A report on the limestones and cement materials of north Georgia

GEOLOGICAL SURVEY OF GEORGIA
S~ .W. :ty.IcCALLIE, State Geologist
BULLETJN No. 2 7
A REPORT
ON THE
LIMESTONES AND CEMENT MATERIALS
OF
NoRTH GEoRGIA

BY T. POOLE MAYNARD. Ph. D.
Assistant State Geologist
Atlanta, Ga. CHAS. P. l;IYRD, State Printer
1912

LIMESTONE AND CEJiENT MA1.'ERI.t1LS OF GEORGI.t1

PLATE !-Frontispiece

PLAN'!' 0.1!' 'l'HJ; PUWUON'l' POR'l'LAND CE~IBN'l' COMPANY, POLK 'OUN'l'Y, GEORGIA

THE ADVISORY BOARD
OF THE,
Geological Survey of Georgia
In the Year 1912
(Ex-Officio) Rrs ExcELLENCY, JOSEPH 1.L BROWN, Governor of Ge-orgia
PRESIDENT OF THE BoARD
HoN. PHILIP COOK___________________ Secretary of State RoN. W. J. SPEER_______________________ State Treasurer HoN. W. A. WRIGHT________________ Comptroller-General HoN. T. S. FELDER_____________________Attorney-General HoN. J. J. CONNER__________ Qommissioner of Agriculture HoN. M. L. BRITTAIN _____ Commissioner of Public Schools

LETTER OF TRANSMITTAL
GEOLOGICAL SURVEY OF GEORGIA,.
ATLANTA, August 26, 1912.
To His Excellency, JosEPH M. BROWN, Governor arnd Presi-
dent of the Advisory Board of the Geological Survey of
Georgia.
SrR: I have the honor to transmit herewith the report of' Dr. T. Poole Maynard, formerly assistant State geologist of this Survey, on the Limestones and Cement Materials of North Georgia to be published as Bulletin No. 27 of this Survey.
Very respectfully yours, S. \711. McC.ALUE; State Geologist.

TABLE OF CONTENTS

PAGE

ADVISORY BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

LETTER OF TRANSMITTAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

,V

TABLE OF CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii-xix

LIST OF ILLUSTRATIONS ............................................. xxi-xxiii

PREFACE ............................................................ xxv-xxvi

LIMESTONES, CLAYS, SHALES AND SLATES............................ 1-28

Limestone . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25

Origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Physical character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2

Chemical character .................................. , . . . . . . . . . 2-3

Uses of limestones and limes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Metallurgical uses ... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Lining of furnaces. . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . .

3

Blast furnace flux... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Fluxing stones used in the production of steel ............. , 5-6

Copper smelting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Lead smelting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8

Glass manufacture ... -... ; ...........-.................... 8-9

Chemical uses . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . 9-11

Sodium carbonate ............................. . . . . . . . . . Calcium chloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calcium carbide Calcium nitrate ....................................... . Dyed textiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............. . Carbonic acid gas ...................................... . Other chemical uses .................................... . Crushed limestone ......................................... . Road metal ........................................... . Ballast ...................................... : . ....... . Concrete ............................................... . Flooring .............................................. . Building stones ........................................... . Mortars and plasters....................................... . Agricultural purposes ...................................... . Chemical function of lime ............................... . Physical effect : . ...................................... . Amount of lime to be used .............................. . Lithographic stone ........................................ .

9-10 10 10 10 10
10-11 11
11-12 11
11-12 12 12
12-13 13-14 14-16
14 14-15 15-16 16-17

vili

CONTENTS

Paper manufacture ........................................ . Leather manufacture ...................................... . Sugar manufacture ... ~ : .................................... Manufacture of glue ....................................... Soap and candles ......................................... Ground limestone ..........................................
Agricultural purposes .................................. . Burning of limestones ...............'....................... .
Intermittent kilns ...................................... Continuous kilns .......................................... .
Vertical kilns with m:ixed feed .......... , ............... . Vertical kilns with separate feed . . . . . . . . . . . . . . . . . . . . . . . . .
Ring or chamber kilns .................................
Rotary kilns .......................................... . ;Fuel used in lime burning .................................. . Classification of common limes ................................. .
High-calcium limes .. ; . . . . . . . . . . . . . . . . .............. . Magnesian limes ...................................... Dolomitic limes and dolomites .............................. Argillaceous limes ....... , .. '............................. Hydrated lime ............................................... . Method of manuf~cture................................... . Advantages of hydrated lime . ; .......................... Uses of hydrated lime ...... ,., ...... : ................. . Literature on hydrated lime ... ; .......................... . Clays, shales, and slates .......... , .............................. Clays ...................................................... . Origin ....... ~ ......................................... Physical character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... Chemical character ....................................... Shales and slates............................................. . Origin ..................................................... . Physical character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chemical character ......................................... Classification of shales .....................................
S'iliceous shales ....................................... Aluminous shales ...................................... . Ferruginous shales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calcareous shales .....' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. CaJrbonaceous shales ............. '...... ~ ............... .

PAGE.
17 17 17 18 18 1818 18-21 19 19-20 19" 20 20 20 20-21 21-23. 21-22 22 22-23 23 23-25 23-24 24 24-25 2525-28 25-26 25 26 26 26-28 26 26-27 27 27-28 27 27 27-28 28 28

HYDRAULIC LIMES, NATURAL AND PORTLAND CEMENTS ................
The relation of hydraulic limes, natural and Portland cements ...... . Hydraulic limes . : ........................ ...................... .
Eminently hydraulic lime ................................... .

29-74 29-30 30-32
31

CONTENTS
PAGE
Grappier cements ...................................... . 31 Feebly hydraulic limes ..................................... . 31-32
Raw materials ......................................... . 31 Selenitic lime ......................................... . 31 Burning hydraulic limes .................. .................... . 31-32 The evolution of cements ....................................... . 32-33 Natural cements ............................................... . 33-38 Raw materials ............................................. . 34 Compos"ition .............................................. . 34-36 Manufacture .............................................. . 36-38 Winning the raw materials .............................. . 36-37 Types of kilns ......................................... . 37 Burning ............................................... . 37-38 Crushing and grinding..................................._. 38 The nature of Portland cement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-41. Portland cement ................................................ . 41-58 Raw materials ............ .- ............................... . 41-42 Calcareous materials ..................................... . 42-44 High-calcium limestones ................................ . 43 Argillaceous limestones ................................ . 43-44 Marls ................................................ . 44; Argillaceous materials ................................... . 44-45 clays ................................................ . 45 Shales and s'lates ........................... _.. _.......... . 45 Chemical ingredients ....................................... . 45-46 Chemical interpretation .................................... . 46"47 Calculation of cement mixtures .... ; ......................... . 47-49 Transportation facilities and markets ........................ . 49' Conditions affecting development. ........................... . 49-56 Determination of quality............................... . 49-50 Determination of quantity .............................. . 50-51 Relation to topography and drainage ..................... . 51 Overburden ............................................ . 51 Location with respect to fuel supply ...................... . 51-52 Coals accessible to North Georgia .......................... . 52-56 Chattanooga district ................................... . 52-53 Georgia coals .......................................... . 54-56 Winning the raw materials ............. ' .................... . 56 Process of manufacture ..................................... . 57 Limestone ............................................. . 57 Shale ................................................ . 57 Mixture of limestone and shale........................... . 57 Hints on construction of plants .............................. . 58 Slag or Puzzolan cements ....................................... . 58

X

CONTENTS

PAGE:
Oxychloride cements ............................. _. ............. . 59 History of cement development in the Southern States .............. . 59-74

Maryland ................................................... . 62-6'3' Security Cement and Lime Company...................... . 62 Tidewater Portland Cement Company .................... . 62-63

Virginia .................................................... . 63-64 Virginia Portland Cement Company ..... , ................ . 63-64 Norfolk Portland Cement Corporation .................... . 64

West Virginia .............................................. . Buckhorn Portland Cement Company ..................... .
Kentucky ................................................... . Kosmos Portland Cement Company ....................... .

65 65 65-66 65-6'6

Tennessee .................................................. . 66-67

" Dixie Portland Cement Company ......................... .

66

'Clinchfield Portland Cement Company .................... . 66-67

Georgia .................................................... . 67-68. Southern States Portland cement Company ............... . 67 Piedmont Portland Cement Company ... , ................. . 68

Alabama ......... .......................................... . S'outhern Cement Company .............................. . Standard Portland Cement Company ..................... . Atlantic and Gulf Portland Cement Company .............. . Alabama Portland Cement Company...................... . Mobile Portland Cement and Coal Company ............... .

68-70 68 69
69-70 70 70

Oklahoma .......... .................. , ...................... . Dewey Portland Cement Company ........................ . Oklahoma Portla?d Cement Company ..................... . Choctaw Portland Cement Works ........................ .

70-72 70-71
71 71-72

Texas Alamo Cement Company ................................ . Texas Portland Cement Company........................ . Southwestern States Portland Cement Company ............ . Southwestern Portland Cement Company .................. .

72-74 72 73
73-74 74

PHYSIOGRAPHY, STRUCTURE AND' GEOLOGY OF NORTH GEORGIA .......... . 75-108 Physiography ................................................. . 75-77 Piedmont Plateau ...................'......................... . 75 Appalachian Mountains ...................................... . 75 Appalachian Valley .......................................... . 75-77 Cumberland Plateau ......................................... . 77 Structure ............. ~ . . . . . . . . . . . . . . . . . . . . . . . . . . ............. . 77-78 Piedmont Plateau ...................... : .................... . 77 Appalachian Mountains ...................................... . 77-78 Appalachian Valley ......................................... . 78-

CONTENTS

xi

PAGE.

Cumberland Plateau ......................................... . 78

Geology ...................................................... . 79-108

Piedmont Plateau .. , ........................................ .

79

Appalachian Mountains ...................................... . 82-83

Murphy marble ......................................... . 82-83

Areal distribution ..................................... .

82

Lithologic character . . . . . . . . . . . . . . . ................... . 82-83

Paleontology .......................................... . 83

.Appalachian Valley and Cumberland Plateau ................... . 83-108

Cambrian ................................................. . 83-90

Weisner quartzite ....................................... . 84-85

Areal distribution ..................................... . 84-85

Lithologic character ................................... . 85

Paleontology .......................................... .

85-

Beaver limestone ........................................ . 85-86

Areal distribution ..................................... . 86

Lithologic character .. : ................................ .

86

Paleontology ................. ......................... . 86

Apison shale .............................. .............. . 86-87

Areal distribution ..................................... . 86

Lithologic character ................................... . 86

Paleontology .......................................... . 87

Rome formation .. , ...................................... . 87-88

Areal distribution ........... , ... , ...... , , . , . , .-..... -... . 87 -

Lithologic character .................................... . 87-88

Paleontology .......................................... . 88

Connasauga shales' and limestones.; .................... .... . 88-90

Areal distribution ..................................... . 88-89

Lithologic character ................................... . 89

Paleontology .......................................... . 90

Cambro-Ordovician ........................................ . 91-92

Knox dolomite .......................................... . 91-92

Areal distribution ..................................... . 91

Lithologic character ................................... . 91-92

Paleontology ................................... : ....... . 92

Ordovician ............................................... . 92-97

Chickamauga formation .................................. . 93-97

Areal distribution ..................................... . 94-95

Lithologic character ................................... . 95-97

Chickamauga limestone .............................. . 96

Rockmart shales and slates ........................... . 96-97

Paleontology .......................................... . 96-97

Western basin ....................................... . 96

Eastern basin ....................................... . 9T

xii

CONTENTS

PAGE
Silurian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 97-99 Rockwood formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97-99 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97-98 Lithologic character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Paleontology ....................... , . . . . . . . . . . . . . . . . . . . 99
Devonian ........................... , ..................... 100-102 Armuchee chert .......................................... 100-101 Areal distribution ...................................... 100-101 Lithologic character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Paleontology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Chattanooga black shale ................................... 101-102 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Lithologic character ................................... 101-102 Paleontology . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . 102
Carboniferous ........................ :.. .................... 102-108 (Mississippian) .......................................... ,102-107 Fort Payne chert ......................................... 102-103 Areal distribution .... : ...... ; .......................... 102-103 Lithologic character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Paleontology ............................... . . . . . . . . . . . . 103 Floyd formation .................... , .................... 103-104 Areal distribution .. , ......... ; ........................ 103-104 Lithologic character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Paleontology ................. , . . . . . ... . . . . . . . . . . . . . . . . . 104 Oxmoor sandstone ....................... ~ . .' ............... 104-105 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Lithologic character .................................... 104-105 Paleontology ....................................... , . . . 105 Bangor formation ......................... : ............ 105-107 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Lithologic character ....... : ............................ 105-106 Paleontology ......... ................................. 106-107 (Pennsylvanian) .......................................... 107-108 Lookout formation ....................................... 107-108 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Lithologic character . . . . ..... r 107-108 Paleontology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Walden sandstone .... ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 . Lithologic character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Paleontology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
LIMESTONES .A.ND CEMENT MATERIALS OF THE PIEDMONT PL.A.TE.A.U .A.ND
APP.ALAOHIA.N MoUNTAIN AREAS IN GEORGIA ... 109-128
Piedmont Plateau ............................................ 109-114

CONTENTS

xiii

PAGE
Geology ........... .......................................... 109-110 Description of indiYic1nal localities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110-114
Stephens County ............................ -.. . . . . . . . . . . . . . no One mile west of the mouth of Panther Creek. . . . . . . . . . . . . . no
Habersham County .......................................... 110-112 One-fourth mile south of the mouth of Little Panther Creek .. 110-n1 Billy Walker quarry .................................... 1n-112
Hall County ...............................................112-n4 C. L. Deal Manufactur1ng Company ....................... 112-114 Conditions affecting development. . . . . . . . . . . . . . . . . . . . . . . 113 Development ......................................... 113-114 Flowery Branch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Appalachian Mountains ..... .................................... 115-128 Fannin County .............................................. 115-117 Geology ................................................... 115-116 Description of individual localities ............................ 116-117 One mile east of Mineral Bluff. . . . . . . . . . . . . . . . . . . . . . . . . . . 116 The Dickey property .................................... 116-117 Gilmer County ............................................... 117-119 Geology ................................................... 117-118 Description of individual localities ............................ 118-119 Holt property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 North Georgia Marble Company.......................... 118-119 Pickens County .............................................. 119-128 Geology ............. ........ , ............................. 119-120 Description of individual localities ............................ 120-128 King JYLarble Company. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Detroit Marble Company ................................. 120-121 Whitestone Marble Company ............................. 122-123 Crystal Marble Company ..... ~ .......................... 123-124 Two miles northeast of Jasper. . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Perseverance quarry .................................... 124-125 Georgia Marble Company ................................ 125-126 Southern Marble Company ...............................126-127 Amicalola Marble Company. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Cherokee County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Description of individual localities... . . . . . . . . . . . . . . . . . . . . . . . . . 128 Seven miles northwest of Canton ........... . . . . . . . . . . . . . . . 128
LIMESTONES AND CEMENT MATERIALS OF THE APPAL."..CHIAN VALLEY AND
CUMBERLAND PLATEAU AREAS IN GEORGIA ...................... 129-278
Polk County .................................................... 129-159 Geology ..................................................... 129-131 Beaver limestone . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129,

xiv

CONTENTS

PAGE
Knox dolomite .......................... . . . . . . . . . . . . . . . . . . . 129 Chickamauga formation ..................................... 130-131
Chicki:unauga limestone ............. : . . . . . . . . . . . . . . . . . . . . . . 130 Rockmart shales and slates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Description of individual localities ............. : ................ 131-159
~1arble Hill ............................................ 131-132 Ellis Davis and Son's slate quarry. . . . . . . . . . . . . . . . . . . . . . . . 132 Rockmart Shale Brick and Slate Company. . . . . . . . . . . . . . . . . 133 Morgan Hills ..........._. .............................. 133-134 Southern States Portland Cement Company ................ 134-143
Conditions affecting development ........................ 136-139 Winning and preparation of limestone ...................139-140 Winning and preparation of the shale ................... 140-141 Mixing limestone and shale ............................ 141-143 Piedmont Portland Cement and .Slate Company ............ 143-149
p
Geologie relations .................................... 143-144 Conditions affecting development ....................... 144-145 Chemical and physical properties ....................... 145-147 Winning and preparation of the limestone................ 14i Winning and preparation of the shale.................... 147 M3xing limestone and shale ............................ 147-148 Geoigia Portland Cement and Slate Company .............. 148-15] Geologie relations .. '...... , ........................... 149-150 Conditions affecting development ....................... 150-151 Southern Lime Manufaetur'ing Company ................... 151-153 Geologie relations .................................... 151-152 Conditions affecting development. . . . . . . . . . . . . . . . . . . . . . . 152 Suggestions in development ............................ 152-153 Development .............. : ...... .". . . . . . . . . . . . . . . . . . . 153 Three-fourths mile northeast of Red Ore .................. 153-154 Aragon Station, Seaboard Railroad. . . . . . . . . . . . . . . . . . . . . . . 154; Aragon Springs ........................................ 154-155 Davitte property ....................................... 155-156 Bald Mountain Portland Cement Company ................. 156-157 Deaton's iron ore pit ................................... 157-15.8 Vicinity of Cedartown. . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . 158 Youngs station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~ 159 Floyd County .................................................. 159-179 Geology ..................... : . ............................... 159-163 Beaver limestone ............... . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Connasauga shales and limestones .............................. 159-160 Knox dolon1ite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Chickamauga formation ..................................... 161-162 Fioyd formation .............................. .' ............ 162-163

CONTENTS

XV

P.A.GE
Bangor formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Description of individual localities. . . . . . . . . . . . . . . . . . . . . . . . . . 163-179
Haynie ................................................ 163-164 Henry Bass property. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Southwest Rome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Northeast Rome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Six-mile Station . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 166 Big Cedar Creek exposure ................................ 166-167 Exposure near Pinson.................... . . . . . . . . . . . . . . . 167 Exposure near N annie. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Oostanaula River exposure ............................... 168-169 J. Scott Davis property................... . . . . . . . . . . . . . . . 169 West side of Lavender Mountain ......................... 169-170 Beach Creek exposure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Lavender Station ................................ : . . . . . . 172 Halls Mountain ......................................... 172-113 Huffaker limestone quarry ................... _- ........... 173-174 Little Dry Creek ........................... . . . . . . . . . . . . . 17~ Floyd County quarry .................................... 174-175 D. B. F. Sellman property ............................... 175-176 Heath Creek exposure, Big Texas Valley................... 176 Orsman ............................................... 176-17'7 One and one-half miles southwest of Orsman ............... 17'7-178 Two miles southwest of Orsman........... . . . . . . . . . . . . . . . . 1'78 Willingham-Harvey-Lipscomb property .......... ......... 178-179 Chattooga County .............................................. 1'79-199 Geology ............................... : ..................... 179-182 Connasauga shales and limestones ............................ 179-180 Knox dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Chickamauga formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Rockwood formation .................................. . . . . . . 181 Floyd foTmation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 BangoT foTmation .......................................... 181-182 Description of individual localities .............................. 182-199 Buckels limestone quarry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Two and one-half miles southeast of Trion. . . . . . . . . . . . . . . . . 183 One and one-half miles north of Trion .................... 183-184 Bald Mountain ...................... .- ................. 184-185 J\1enlo .................................................. 185-187 Shackleton ............................................. 187-188 Gore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . 188 Two miles northeast of Gore ............................. 188-189 Four miles southwest of Subligna ......................... 189-190 Subligna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

xvi

CONTENTS

P.A.GE
One and one-half miles northwest of Crystal Springs ........ 190-191 Tidings ............................................... 191-192 One and one-half miles north of Kartah ................... 192-193. Gaines property ............. ; .........................193-194 Robinson property .................................... 194-195 Two miles west of Menlo ................................195-196. Cedar Poi~t . , ......................................... 196-19T Neals Gap .............................................. 19T-19& Martins Cave .......................................... 198-199 Dade County ...................... : .......................... 199-218 Geology ..................................................... 199-20(} Chickamauga formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 Rockwood formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 Bangor formation .......................................... 199-200 Lookout formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 Description of individual localities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201-218. Trenton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Tatum . . . . . . . . . . . . . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 202 One-half mile west of Trenton ...... , .................... 202-203. One mile northwest of New England...................... 203. One and three-fourths miles s'outh of Rising Fawn .......... 203-204 Southern !ron and Steel Company .......................... 204-208 Four miles northeast of Rising- Fawn. " .................... 209-21(} Sitton Gulf ...................... ; . . . . . . . . . . . . . . . . . . . 210 Two p.1iles east of Trenton .............................. 210-211 I Two. and one-half miles southwest of Trenton.~ ............ 211-212 Two and. one-half miles northwest of New England .... : .... 212-2f3 Three miles north of New England ................. .'... 213-214 One and one-half miles northwest of Trenton .............. 214-215Two miles west of Rising Fawn ........................ 215,216 Proctors Bluff ...... , ... ............................... 216-217 Four miles southwest o Trenton, .... ,.................... 218 Walker County ........................ ........................219-245 Geology .......... ........................................ 219-220 Connasauga sh~les and limestones.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Knox dolomite ................... , . . . . . . . . . . . . . . . . . . . . 219 Chickamauga formation ............. , . . . . . . . . . . . . . . . . . . . . . . . 219 Rockwood formation ............. ........................... 219 Floyd formation ............ ........ .. . . . . . . . . . . . . . . . . . . . . . 220 Bangor formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Description of individual localities .............................. 220-245 Chickamauga Cement Company .......................... 220-226
Geologic relations ........ , ......................... 221-222Conditions affecting development . . . . . . . . . . . . . . . . . . . . . . . 222-224-

COKTEKTS

xvii

?AGE
Winning and preparation of the raw material. ........... 224-225 Manufacture of hydrated lime. . . . . . . . . . . . . . . . . . . . . . . . . . 225 Manufacture of natural cement. ........................ 225-226 Trouth and Company's quarries . . . . . . . . . . . . . . . . . . . . . . . . . . . 226-227 Catlett Gap road. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 McLamore Cove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Horine Development Company ............................ 229-232 Geologic relations .................................... 229-231 Chemical interpretation ............................... 231-232 Conditions affecting develop'ment. . . . . . . . . . . . . . . . . . . . . . . . 232 Shinbone Ridge ............... , ........................ 232-234 West side of Pigeon Mountain .................... ...... 234-235 Two and one-half miles southwest of Copeland ............. 235-236 Jackson property ................. : . ... . . . . . . . . . . . . . . . . . . 236 Brum property ........................................ . 237 Nickajack Gap road, east side of Lookout Mountain . . . . . . . . 237-238 McLamore Cove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Dougherty Gap ........................................ 239-240 Coulter property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 One mile southwest of Cedar Grove post office. . . . . . . . . . . . . 240 Bowers Gap ......................................... . . 241 One-half mile west of Cassandra. . . . . . . . . . . . . . . . . . . . . . . . . . 242 One and one-haif milesnorthwest of Cassandra. . . . . . . . . . . . . 243 Southern Iron and Steel Company ........................ 243-245 Catoosa County ................................................ 245-257 Geology . .................................................... 245-247 Rome formation .......................................... : 245 Connasauga shales and limestones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 Knox dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 Chickamauga forma_tion . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 Rockwood formation ..................... :. . . . . . . . . . . . . . . . . 246 , Bangor formation ....................... : .................. 246-247 Description of individual localities .............................. 247-257 Fort Oglethorpe well No.5 ............................... 247-249 Graysville Mining and Manufacturing Company ............ 249-254 :Hale property ......................................... 254-256 Cedar Bluff ............................................ 256-257 Whitfield County ................................................ 258-264 Geology ...................... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Connasauga shales and limestones ............. . . . . . . . . . . . . . . . . .258 Chickamauga formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Rockwood formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Description of individual localities................... : ......... 259-264 Du.cketts Mill .......... .............. : . . . . . . . . . . . . . . . . . 259

xviii

CONTENTS

PAGE
One mile north of Ducketts Mill. . . . . . . . . . . . . . . . . . . . . . . . . . 260.Jet Black Marble Company .............................. 260-261 Cedar Ridge, north of the Dalton-Dawnville road ........... 261-26Z Four miles northeast of Dalton ........................... 262-263 Two miles due north of Dalton. . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Three and one-half miles east of Waring. . . . . . . . . . . . . . . . . . 264 Dantzler property . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Mur~ay County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Connasauga shales and limestones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Knox dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Chickamauga formation . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Gordon County .................. ' .... : ......................... 266-267 Geology ...................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 -Connasauga shales and limestones. . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Knox dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266Desc:ription of individual localities .............................. 266-267 One mile southeast of Fairmount ................ ......... 266-jti'/ One mile southwest of Fairmount.......................... 2~)7' One mile northeast of Pine Log Creek..................... 267 Bartow County .................. ."............................. 267-278. Geology ..... , ................. ' ............................. 267-268. Beaver limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Rome formation ...................... .... , . . . . . . . . . . . . . . . . . 267 Connasauga shales and limestones ....... , . . . . . . . . . . . . . . . . . . . . . 268~ Knox dolomite ........... : . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . 268 Chickamauga limestones and Rockmart shales. . . . . . . . . . . . . . . . . . 268. Description of individual localities .............................. 268-278 Two miles south of S'ophia .............................. 268-269 Fols'om . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26!f Four miles east of Folsom ............................... 269-270 Georgia Green Slate Company ............................ 270-271 Ladd Lime Company .................................... 271-273.
Geologic relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Physical and chemical character. . . . . . . . . . . . . . . . . . . . . . . . . 272 Conditions affecting development ....... ; .. : . .... .'...... 272-273: Development ....... , ................. .'................ 273 Uses ................................ , . . . . . . . . . . . . . . . 273 Howard Hydraulic Cement Company...................... 273-275 Geologic relations .............................. ,. . . . . . 274 Conditions affecting development. . . . . . . . . . . . . . . . . . . . . . . 275 Development ............ :. . . . . . . . . . . . . . . . . . . . . . . . . . . . 275. Clifford Lime and Stone Company........................ 276-277 Geologic relations .................................... 276-277'

CONTENTS

xix:

PAGE
Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Uses .....................................................'.............. 277 Paul F. Akin property ................................... 277-~78 APPENDIX ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279-285 United States Government Specification for Portland cement ........ ~ .. 280-~81
Specification ................................................... 28G-281
Interpretation of results ............. ............................ 281-285

ILL US TRA TIONS

PLATE
I. Plant of the Piedmont Portland Cement Company, Portland, Polk County, Georgia ................................. Frontispiece

II. III. IV.
Y. VI. VII. . VIII.
IX.
X.
XI.
XII.

FACING PAGE
An outcrop of white Murphy marble at the Perseverance quarry, 2 miles east of Jasper, Pickens County, Georgia. . . . . . . . . . . . . 48
Marble Bluff, near Whitestone, on the Louisville and Nashville Railroad, Gilmer County, Georgia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
An exposure of Weisner quartzite along the Western and Atlantic Railroad, at the iron bridge over the Etowah River, 1 mile east of Cartersville, Georgia, showing the crushing and folding of the quartzite. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
A view showing outcrop of black marble at the quarry of the American Black Marble Company, Whitfield County, Georgia... . . . . 88
Residual chert and clay resulting from the, weathering of the Knox dolomite, in a cut on the Central of Georgia Railway, near Summerville, Chattooga County, Georgia. . . . . . . . . . . . . . . . . . . 92
A cut on the Chattanooga Southern Railroad, at Estelle, walker County, Georgia, showing shales and sandstones associated with the fossil iron ores .................................. 102
A. Rockmart slates. Quarry of the Rockmart Shale Brick anu Slate Company, Rockmart, Polk County, Georgia. . . . . . . . . . . . 122
B. Mill of the Whitestone Marble Company, Whitestone, Pickens County, Georgia. Quarry immediately east of the mill. ..... 122
A. Murphy marble, Detroit Marble Company, Whitestone, Pickens County, Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
B. Quarry of the Georgia Marble Company, near Tate, Pickens County, Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
A. Rockmart slates. Quarry of the Black Diamond Slate Company, about 2 miles northeast of Rockmart, Polk County, Georgia. . 130
B. Rockmart slates. Artificial cut made by Seaboard Railroad immediately south of Rockmart, Polk County, Georgia. . . . . . . . . 130
A. Chickamauga limestone. Quarry No. 3, Southern States Portland Cement Company, Rockmart, Polk County, Georgia. . . . . 144
B. Chickamauga limestone. A portion of quarry No. 1, Southern States Portland Cement Company, Rockmart, Georgia. . . . . . . 144
A. Chickamauga limestone oYerlain unconformably by Rockmart

xxii

ILLUSTRATIONS

FACING

PLATE

PAGE

shales and slates. Quarry No. 3, Southern States Portland

Cement Company, Rockmart, Polk County, Georgia. . . . . . . . . . 140

B. Mill of the Southern States Portland Cement Company, Rock-

mart, Polk County, Georgia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

XIII. A'. Chickamauga limestone. Quarry of the Piedmont Portland Ce-

ment Company, Por,tland, Polk Co11nty, Georgia ............... 146

B. Chickamauga limestone. Quarry of the Bald Mountain Portland

Cement Company, 114 miles north of Aragon Springs, Polk

County, Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

XIV. A. Chickamauga limestone. Quarry of the Southern Lime :iY.4anu-

facturing Company, Aragon, Polk County, Georgia. . . . . . . . . . 152

B. Rockmart siates. Quarry of Ellis Davis' Sons, Rockmart, .Polk

_ County, Georgia, showing cleavage. Bedding not shown. . . . . 152

XV. A. Argillaceous limestone in the Floyd formation. Quarry located

in the city limits of Rome, at the intersection of the North

Attalla Railroad and the Rome-Summerville public road. . . . . 174

B. Stone crushing plant owned by Floyd County, located imme-

diately east of the quarry in A ... , ........................ 174

XVI. A. Bangor limestone, about 5 miles. north of Crystal Springs, on the

Robinson property, Chattooga County, Georgia.............. 194

:B. Shales at the top of the Floyd formation, about 5 miles north of

Crystal Springs, on the Robinson property, Chattooga County,

Georgia ................ : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

XVII. A. Bangor limestone. Lower quarry of Southern Iron and Steel

Company, 1 mile northeast of Rising Fawn, Dade County,

Georgia .......................... , :,. . . . . . . . . . . . . . . . . . . . 208

B. Knox dolomite. A section of quarry, Ladd Lime Company, near

Cartersville, Bartow County, Georgia. . . . . . . . . . . . . . . . . . . . . . 208

XVIII. A. Trauth and Company's Quarry. . Chickamauga limestone, near

Chickamauga station, showing the variable thickness of the

bedding, Walker County, Georgia. . . . . . . . . . . . . . . . . . . . . . . . . . 226

B. Lime kilns and mill of the Chickamauga Cement Company, Ross-

ville, Walker County, Georgia ............................. 226

XIX. A. Connasauga limestone. Portion of quarry of the Graysville Min-

ing a~d Manufacturing Company, immediately west of Grays-

ville, .Catoosa County, Georgia ............................ 248

J3. Knox dolomite. Eastern end of quarries of Graysville Mining

and Manufacturing Company, east of Graysville, Catoosa,

County, Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

XX. A. Reel iron ore on the Rockwood shales, Peters property, Taylor

Ridge, Chattooga County, Georgia ........................ 252

J3. Close view of marble quarry, showing massive and heavy-bedded

Knox dolomite, Catoosa County, Georgia ................... 252

ILLUSTRATIONS

xxiii

PLATE
XXI.
XXII.

FACING PAGE
A. Quarry of Knox dolomite. Kilns and stone house, Hale prop-
erty, about J.lh miles southeast of Graysville, Catoosa County,
Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 B. Knox dolomite. Ladd Lime Company's quauy, showing heavy-
bedded and massive dolomite, Bartow County, Georgia. . . . . . . 256 A. Ladd Lime Company. Located about 2 miles southwest of Car-
tersville, Bartow County, showing Ladd 's mountain, lime kilns, and crushed stone bins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 B. Lime kilns and cement mill, Howard Hydraulic Cement Company, Cement, Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

FIGURES
1. Ta'ble showing production of Natural and Portland cements in the United States, and of Portland cement in the Southern States, since 1890. . . . . 61
2. Map showing the physiographic subdivisions of Georgia. . . . . . . . . . . . . . . . . 76 3. Map showing the areal distribution of marbles and limestones in the Pied-
mont Plateau and Appalachian Mountain areas of Georgia. . . . . . . . . . . 80 4. Map showing the location of mill and quarries of the Southern States Port-
land Cement Company ..................... : ................. : . 0 135 5. Map showing the location of the property, mill, and quarry of the "Pied-
mont Portland Cement Company, Portland, Georgia ..... 0 143 6. 11:ap showing the Nat11ral cement outcrop in the vicinity of Rossville, Ga .. 221

MAPS
1. Geological map of the Appalachian Valley and Cumberland Plateau areas of Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 .

PREFACE
The writer desires to present in this report the results of his researches on the lime and cement materials of North Georgia, and after careful consideration of all the conditions pertaining to their commercial development to make known for what purposes these materials can best be used.
All the literature at the writer's command has been made use of in preparing that portion of the report which deals with limestones and cements, their manufacture, uses, etc. The geology of the Appalachian Valley and the Cumberland Plateau is discussed in more detail than is usual in an economic report. An intimate knowledge of the geology of this area was essential in order to fully comprehend the possibilities of the undeveloped deposits. Every outcrop of limestone of any commercial importance, together with the associated shales, has been sampled and analyses have been made. Especial care was taken not only to locate definitely on a topographic map the position of the section, but to describe carefuly each lithologic unit, and to show in the sections described the character of the unit corresponding to any analysis.
The maps accompanying this report show the distribution of the lime and cement materials in the Piedmont Plateau, the Appalachian ).(fountains, the Appalachian Valley, and the Cumberland Plateau, along with the definite location of more than 350 samples which were analyzed by Dr. Edgar Everhart, chemist of the Geological Survey of Geo,rgia.
The discussion of the lime and cement materials by districts or by lesser physiographic and geologic subdivisions is usually preferable to the geologist; however, the description of individual localities by counties makes the information in this report more accessible to the property owners, for which reason this report has been arranged to conform with other reports issued by the Survey.

xxvi

PREFACE

The writer desires to express his sincere thanks to Prof. S. W. McCallie for many valuable suggestions in the preparation and revision of the manuscript. Dr. Edgar Everhart, chemist of the Geological Survey of Georgia, and- Mr. Clarence N. Wiley, general manager of the Atlantic and Gulf Portland Cement Company, have always gladly co-operated and given their advice freely. The writer is also indebted to the general managers and chemists of the Southern cement mills and the lime manufacturers of Georgia for their many courtesies.

/

LIMESTONE AND CEMENT MATERIALS OF
NORT-H GEORGIA
LIMESTONE, CLAYS, SHALES AND SLATES
LIMESTONES
ORIGIN
Lime (calcium) occurs originally in the igneous rocks of the earth's crust, where it is found in combination with a great number of substances and is an important constituent in a large number of rockmaking minerals. Lime never occurs in nature as such, but always in combination with other constituents as carbonate, sulphate, silicate, phosphate, etc. On account of its ease of combination there are a great number of rock-making minerals containing a large percentage of lime.
By the action of water and the acids of the atmosphere and lithosphere, lime is dissolved. The analyses of river waters show them to contain a considerable amount of carbonic acid. This holds the lime in solution and it is carried by the rivers to the sea where limestones (carbonates of lime with varying amounts of impurities) are formed, either from the accumulation and ultimate consolidation of the fossil remains of organisms which secrete lime or from the chemical precipitation of lime from solution.
The limestones of North Georgia are all of marine origin. They may be divided, for convenience of description, into five distinct types, namely: high-calcium limestones, magnesian limestones, argillaceous limestones, dolomites, and high-calcium .or dolomitic marbles. The differences in these calcium and magnesium carbonates are due sometimes to conditions of deposition depending on their origin, either from the accumulation of organic remains, deposition due to chemical

2

GEOLOGICAL SURVEY OF GEORGIA

precipitation, by the admixture of argillaceous sediments, or to sub- .

sequent causes.

PHYSICAL CHARACTER

Limestones show wide differences in physical character. The

physical character is usually a criterion of the chemical composition.

Limestones vary in color from pure white to black, depending on

differences in chemical composition. The amorphous and semicrystal-

line limestones are usually light gray to bluish gray in color, or

? -



'

variegated. In the highly crystalline limestones the impurities may

be crystallized and segregated in bands or the coloring matter may be

uniformly disseminated throughout or irregularly distributed.

Limestones vary in texture from am?rphous and semi-crystalline

to crystalline: Variation in density and absorption properties are due

largely to differences in texture.

Limestones vary in hardness, specific gravity and compactness from

the unconsolidated shell marls to the crystalline marbles. Many va-

rieties of limestone are named on the basis of chemical composition,

as high-calcium, magnesian, dolomitic, etc. Special names are also

given because of their structure or most abundant accessory con-

stituent, as argillaceous, chalky, sillceous, bituminous, oOlitic, and

pisolitic; and still othe~s a~e named from certain predominant fossils

as crinoidal, coralline, and formaniferal.

<mEMICAL CHARACTER
The chemical composition of a pure limestone is expressed by the
+ formula, CaC03 (calcium carbonate) or CaO (calcium oxide) 56 per
cent. C02 (carbon dioxide) 44 per cent. Limestones seldom occur without the presence of other constituents. Calcium carbonate ~s the most abundant constituent, and a rock must contain at least 50 per cent. calcium carbonate to be termed a limestone.. Silica, magnesia, alumina, the alkalies, etc., occur in less .abundance in the limestones and are usually referred to as impurities or accessories. While a very pure limestone is valuable, especially for certain metallurgical and chemical purposes, it is often the accessory constituents or impurities that make the limestone equally as valuable.

LIMESTONES, CLAYS, SHALES AND SLATES
The classification of limestones depends largely on their chemical composition. A limestone very high in calcium carbonate with a small percentage of impurities is known as a high-calcium limestone, while limestone containing more than five per cent. of magnesium carbonate is known as a magnesian limestone. When 30 per cent. or more of magnesium carbonate occurs it is known as a dolomite, and when the alumina and silica range from 15 to 20 per cent. the rock is termed an argillaceous limestone. Marble, travertine, calcareous tufa, etc., may have the identical chemical composition of a very pure limestone ; however, they are distinguished by their physical properties and hot by their chemical composition.
UISES OF LIMESTONES AND LIM,E.S
METALLURGICAL UsES Lining of furnaces.-Dolomite is used in basic open-hearth furnaces to re~air the scarification of the hearth due to the action of the slag. The furnace structure consists of a~ outer lining of common brick with an inner permanent lining of magnesite brick, which may be from two to three feet in thickness, and upon this the crushed basic dolomite is tamped. Calcination of the dolomite and the ,scarification of the hearth, due to the slag, causes the dclomite to be gradually received into the slag and become a part of it, thus adding to the basicity of the slag; however, its assistance is not very great. The stone must be as low in silica, iron and aluminum oxides as possible, so that these acid acting substances will not form sufficient fusible compounds with the bases to lower the refractory properties, and lessen its resistant power to the corrosive action of the furnace burden. The stone for this purpose should approach as closely as possible a theoretical dolomite, so that the content of magnesiamay be high. The higher the content of lime the greater the danger of the disintegration of the lining when the furnace is cooled down, as lime oxide slakes readily, while magnesium oxide is more difficult to slake. Blast furnace flu:r.-High-calcium limestones and dolomitic limestones or dolomites are used for blast furnace :fiuy; In the Pittsburgh

4

GEOLQG-IG.AL SURVEY OF GEORGIA

district and in the East a high-calcium fluxing stone 1s extensively

. used, while in the South dolomite is more. generally used as the

fluxi!J.g stone.

The value of limestones and dolomites for fluxing depends on the

quantity of~the impurities-.silica, alumina, sulphur, and phosphorus-

present, and the preference for a limestone or a dolomite depends

largely on the chemical composition of the ore used. The function of

the fluxing stone is to furnish the .bases (lime.and magnesia) to combine

with the acidic impurities of the ore and coke. As the primary object,

therefore, is to flux the acid impurities it is desirable to secure a lime-

stone or dolomite as free from these impurities as possible. Fluxing

stones are sometimes used containing as much as 10 per _cent. of silica

and aiuinirta; however, those. in general use run less than 2 per cent.

Sulphur a11d phosphorus are almQst always present; however, they

occur in such small amounts that they are not considered .in esti'mating

the value of a fluxing stone, except in the manufacture of Bessemer

iron, in which case the content of phosphorus in the flux~ng stone

should be less than 0.1 per cen~.

':Che factors determining the character o the .:fii:uxdng st0ne most

desirable depends on the chemical composition of the ore and the

character of the product desired. While limestones possess certain

advantages, dolomites also have equal advantages, and, after all, furnace

'

.

.practice in a particular district best determines the character of the

fluxing stone to be used.

Following1 are some of the properties of calcium and magnesium

as fluxes:

The smaller atomic weight of magnesium (40 as compared with 56 for calciu~) enables it to eombine with a larger proportion of acids th~n calcium t'O form a slag of a given. formula. For example, Mg1Si03 con.sists O-f 40 per cent. MgO and 60 per cent. SiO.; while Ca.Si03 consists of 48.28 per cent. GaO and 51.72 per cent. Si02 'This is almost exactly offset by the smaller percentage of MgO in Mg008, 47.62 as compared with 56 per ce.nt. OaO in Oa008 One .
pound of Mg008 will convert .2867 pounds of Si02 to MgSi08, whereas one
pound of Oa008 will convert .2896 pounds of SiO, to OaSiOs..

1Matthews and Grast~, The Limestones of Mar~land: Vol. VIII, pt. 8, 1910, p. 240.

LIMESTONES, CLAYS, SHALES AND SLATES

5

Theoretically, a greater quantity of fuel is required to melt a magnesian slag than a lime slag, as the specific heat of magnesia is greater than that of lime. Furnace practice in the Birmingham district, however, indicates that the fuel consumption is not higher. In this district an enormous amount of slag is carried in the furnace, and when lime is used as a flux the furnace "slips" and "hangs," while a magnesia slag is more fluid and the furnace works smooth and regular.
Magnesia is said to have less affinity for sulphur than lime1 While the lime may be essential with ores high in sulphur, the hard and soft red hematites of the South are practically free from sulphur and the hard calcareous ores, which constitute the greater portion of the furnace burden, furnish sufficient lime to take care of the sulphur m the coke.
The physical conditions essential for the fluxing stone are: (1) the stone must be crushed small enough to pass a four-inch ring and remain on a two-inch ring; (2) the stone must be free from dust.
Fluxing stones used in the production of steel.-Limestones are used in the manufacture of steel in the basic open-hearth process. By the use of limestone, the fluxing of the silica and the alumina takes place, the manganese, carbon, and practically all of the phosphorus and a large portion of the sulphur is removed.
In a letter to the writer, Mr. C. H. Elliott, Superintendent of the Open-Hearth and Bloomington Mill Department, Atlanta Steel Company, says:
:E1or limestone, the specification is simple: as low in silica as possible, also iron and aluminum oxide an:d magnesium carbonate, .and as high in calcium carbonate .as possible. In other words, as pur.e a calcium c.arbonate as one can conveniently 'and economically secure.
Dolomite is used to repair the scarification of the hearth due to the action of the slag. As the dolomite is also received into the slag as it is worn .away and dissoived by the slag and becomes a part of it, it adds to the basicity of the slag, but its assistance is not very great. The specification for dolomite is the same as that for limestone. One would like as near a theoretical dolomite as possible.
In the limestones we try to avoid and reject all samples running under 92 per cent. calcium carbonate, as the presence of more than 3 per cent. Si02 o;r 4 per cent. MgC03 makes the stone undesirable. The silica is undesir-
1Hoffman, iron and steel.

6

GEOLOGICAL SURVEY OF GEORGIA

able because it loweiiS the .effi<;ien.cy o:J; ilie flux for removing the silicon and phosphorus from the molten metal lllnd the magnesia, because it makes the slag too ref~actory and therefore requiring too much heat to !l'educe it to a fluid s~te.
,Southern pig iron- is high .in phosphorus, ranging ftl'om .50 to 1.40 per cent., and to remove this relatively lMge amount of phosphorus requires a slag of 20 per cent. s!i.liCJa or less. If the silica exists in the slag to a greater exten:t than 20 per cent., the .removal of the phosphorus is very uncertain.
The following analyses show the chemical character of the dolomites
and limestones used in the asic open-hearth process' by the Atlanta
Steel Company1

Analyses of Dolomites and Limestones Used by the Atlanta Steel Co.

''

Al:!Os

Dolomites and Limestones

Si02 and- CaCOs MgCOs

Fe20s

'

Dolomite from-
Shook & Fletcher, Birmingham, AI~-------- .96 Birmingham Realty Co., Biimingham, Ala . _ .82 Birmingham Realty Co., Birmingham, Ala __ 2.72

.57 52.82 1.06 53.71 1.74 51.19

45.51 44.91 45.61

Ladd Lime & Stone Co., Cartersville, Ga ___ .68 1.62 52.97 44.99

Limestone from-

Chickamauga Quarrying & Construction
Company, Chattanooga, Tenn_ ---.------- 2.18 American Chemical Manufacturing Co__ . ___ 1.32

.. 72 .34

95.24
95,,"~? ::..,-~

1.86 -----

Copper smelting.-A great deal has been written about the com-

position of copper slags; however, very little information is available

regarding the bases, that is, ferrous oxide, manganous oxide, lime,

magnesia, barite, alumina, zinc oxide, etc., which are among the

principal slag forming substances dealt with in copper srnelting. Of

the above, pnly the calcareous materials, lime and magnesia, will be

discussed.

Limestone and dolomite are both used in copper smelters to add

sufficient basic flux so that the add silica content of the slag will not

reach a maximum of more than 40 per cent. While it is entirely

practicable to make slags which contain more than 40 per cent. of

silica, it is ~ot the general practice. The formation temperature and

1Analyses furnished by Mr. C. H. Elliott, Atlanta Steel Co.

LIMESTONES, CLAYS, SHALES AND SLATES

7

the flowing temperature of a slag depends to a large extent upon the chemical composition of the base present. Very pure high-calcium limestones are used in nearly all copper smelters; however, a dolomite
was used with considerable success at the Golden Reward plant, Deadwood, North Dakota, by Franklin P. Carpenter1 The materials used consisted of siliceous gold ores containing only a trace of sulphur,
pyrite and pyrrhotite; later, this was replaced by siliceous pyritic concentrates from Homestake. The principal basic flux was a dolomitic limestone. The dolomitic limestone was preferred to pure limestone and Mr. Carpenter2 says:
Nothing like a scientific attempt has ever been made to determine tihe forma,tion-poin.t of our slags, hence I can not say that they were less fusible than they would have been with all lime and no magnesia. They did seem more liquid, and c.ertain1y less magnesian limestone was required fo!l" the s~ame work. This was due, of course, to the lower comFbined weight. of magnesia.
. Peters8 says, in regard to the replacement of lime by magnesia:
All experiments with which I am acquainted indicate that the replacement of lime by magnesia causes a moderate rise in the formation temperature until about three-fourths of the lime has been replaced, beyond which limit the .temperature rises with gre,at rapidity.
Some interesting observations were made by Hoffman,4 which are referred to under the discussion of the use of limestone in the metal-
lurgy of lead. Fulton and Knitzen~ are of the opinion that 'csome magnesia up to
8 or 10 per cent. replacing lime is desirable, owing to its greater silica saturating power and the lesser specific gravity of the resultant slag."
The physical and mechanical conditions of ore in the blast furnace
is of very considerable importance in the smelting process. The many difficulties which may result from the "fines" can be largely overcome
by some method of consolidation of "fines" into lumps. No material
1Carpenter, Franklin P., Pyritic Smelting in the Black Hills: Trans. Amer. inst. Min. Eng., Vol. XXX, 1906, pp. 764-777.
2!bid, p. 773. "Peters, E. D., Footnote, Mineral Industry, 1909, p. 246. 4Trans. Amer. Inst. Min. Eng., Vol. XXIX, 1900, p. 642. 5Fulton, Chas. H., and Knitzen, Theodore A., Sulphide Smelting at the National Smelter o! the Horse Shoe Miming Co., Rapid City, S. Dak.: Trans. Amer. Inst. Min. Eng., Vol. XXXV, 1905, p. 329.

8

GEOLOGICAL SURVEY OF GEORGIA

has been more frequently used for this purpose than freshly burned lime: The lime is slaked with considerable water and the resulting milk of lime thoroughly incorporated with the ore until the entire mass is like a thick mortar. The amount of lime necessary for the consolidation of the H:fines" varies according to the physical condition of the ore, the amount of sulphates present, etc. ; however, it is usually from 5 to 12 per cent. Sometimes it is fed into the furance in the form of partially drie(l mud or made into balls- and heated thoroughly dry and hard.. The addition of lime is in almost all cases favorable to subsequent fusion. On account of the ease of consolidation, its general availability, fl.uxir,tg qualities, and cheapness, it is regarded as the most useful substance- known fqr the consolidation of ''fines."
Lead smelting.-The valu~ of iime in the smelting of galena (PbS)
was not recognized until 1907. Previous to thistime, limestone or dolomite was added in the smelting of lead only in the reverberatory proces.s for the mechanical effect of stiffening the ,charge; however, it was observed that when the limestone was a<;lded the charge became glowing, so that it was known that its addition had a chemical as well as a physical effect.
In 1897, Huntington and Haberlein pattented a process of oxidizing galena by forcing air under pressure through a rriixture of galena and lime or limestone and it became established as ,a successful and economic process in 1906.
At the present time, three methods of oxidizing galena by the addition of limestone or gypst1m are carried out on a commercial scale, and are known as lime roasting or "pot roastin,g": (1) the HuntingtonHaberlein process1 ; (2) The Carmichael-Bradford process2 ; and (3) the Solvesberg process8
The chemical effect of the addition of the lime in the various processes has been discussed by many workers and the more important papers have been published in book form by Ingalls.
Glass manufacture.-Limestone has an important use in the manu-

1Eng. & Min. J-our., Vol. LXXX, 1905, p. 106. 2Ingalls, Eng. & Min. Jour., Vol. LXXXI, 1906, p. 9. BMin. Mag., Vol. XII, 1905, p. 391.

LIMESTONES, CLAYS, SHALES AND SLATES

9

facture of glass. Both high-calcium and dolomitic limestones are used and it depends on the character of the finished product as to just what the specifications of the chemical composition of the stone shall be. The function of lime and magnesia is to act as a flux and to combine with the silica to form a silicate. Burchard1 says, "magnesia, which is more apt to be introduced into glass materials through limestone than through sand, is troubleso;ne because it renders the batch less fusible." - While magnesia may be objectionable in the manufacture of certain kinds of glass, considerable quantities of calcined dolomite are used in the manufacture of flint and plate glass.
Glass may be divided into four general classes, namely, plate, window, green bottle, and flint. vVhen limestone is used in the form of carbonate, it is ground fine enough to pass a twenty-mesh sieve or finer. After first crushing the limestone, it is usually ground by rockemory mills or by a mill of the impact pulverizer type.
CHEMICAL Us:ms Sodium carbonate.-The Le Blanc2 process of manufacturing sodium carbonate is as follows: After sodium sulphate (Na2 S04 ) has been formed by the action of sulphuric acid (H2 SO4 ) with sodium chloride (NaCl) at a high temperature, limestone and coal or charcoal is added and calcined in a reducing flame. Sodium sulphate (NaS04 ) +carbon (2C) +limestone (CaC03) =sodium carbonate (Na2CO,J +lime sulphide (CaS)+ carbon dioxide (2C02 ). The carbon dioxide passes off into the air and the sodium carbonate is separated from the ~mlphide of lime by leaching with water at a moderate temperature for the sulphide of lime is practically insoluble in water. The Solvay process with calcium chloride as a by-product is as follo:ws : Carbon dioxide is passed into a solutton of sodium chloride saturated with ammonia. Under certain conditions the reaction is as follows: Salt (NaCl)+ammonia (NH3 )+water (H20)+carbon dioxide (C02)= sodium bi-carbonate (NaHC03) +ammonium chlo-
1Burchard, E. F.; Bull. U. S. Geol. Survey, No. 285, pp. 458-454. 2Encyc. Britan., VoL XXII, p. 242.

10

GEOLOGICAL SURVEY OF GEORGIA

ride (NH4Cl). The sodium bi~carbonate being less soluble than the accompanying compounds is separated by filtering; The solution containing ammonium chloride is treated with calcined limestone. The ammonium gas is liberated and used again in the process, while calcium' chloride and sod-ium chloride are both contained in the waste liquor and the calcium chloride is obtained by crystallization.
. Calcium chloride.-The three important methods of manufacture
of calcium chloride (chloride of lime, muriate of lime, bleaching pow-. der) are: (1) as a by~prodttct in the manufacture of sodium carbonate by the solvay pr-ocess. (In this process more than sufficient is made to supply. the demand) : (2) slaked lime is placed in leaden vats and treated with chlorine gas; (3) dissolving limestone in dilute hydrochloric acid. Calcium chloride crystalizes out when the solution is concentrated by evaporation.
Calcium chloTide is used largely as a disinfectant. When it is heated to redness on platinum it looses practically all of its water and is:<used as a dehydtating agent.
Calci~tm carbide.-This is prepared in the electric furnace by fusing lime oxide.a.nd .carbon in the form of. coke or charcoal. It is used in the manufacture of acetylene gas and cyan amid.
Cyan amid, or "lime nitrogen," is manufactured by passing nitrogen gas, w~ich is obtained from liquid air, over calcium carbide. It is an important fertilizer.
I
Calcium nitrate.-Ground.limestone is an important constituent in the manufacture of calcium nitrate, which is used so extensively as a fertilizer. Calcium: carbonate or lime is treated with nitric acid. Ground limestone is also used as a fertilizer filler.
Dyed textiles.-Ground limestone is used to neutralize the acid condition of dyed textiles.
Carbonic acid gas.-The simplest method of obtaining carbonic
acid gas consists in the calcination of magnesite, which is almost pure
magnesium carbonate (MgC03 ). When magnesite is not available, dolo~ mites are often used. The calcination of calcium carbonate (CaC03 ) will furnish a considerable quantity of carbonic acid gas; however, the

LIMESTONES, CLAYS, SHALES AND SLATES

11

heat required to calcine the calcium carbonate is much higher than that required of magnesium carbonate.
The dolomitic marbles of Pickens County, Georgia, are used by the Pratt Labor~tory of Atlanta in the production of a commerciat carbonic acid gas, in the manufacture of epsom salts and gypsum.
Other chemical uses.-Lime is also used in the manufacture of caustic soda, acetic acid, in the purification of gas and 'water, in the manufacture of Bordeaux mixture, etc.
CRUSHED L~ESTO~~
Road M e'tal.-Limestone for use as road metal should be thoroughly compact and consolidated. The semi-crystalline and. highly siliceous limestones possess the greatest resistance to wear. Limestones possess high cementing qualities and the fines and screenings, when used as a top dressing, fill the empty spaces and give the essential qualities of a good road surface, namely, hardness and smoothness. It is important to know the cementing qualities of the dust produced by any road metal. The consolidated crypto-crystalline and crystalline limestones of North Georgia, and the cherts associated with some of these limestones, are the most important materials used for road. metal in that part of the State. They all possess good wearing and cementing qualities.
Ballast.-In the past, limestones of most any character have been used for ballast without any serious consideration regarding the properties considered today as essential. Limestones are extensively used for ballast on account of the ease with which they can be tamped under the sleepers, their cementing properties, and the cheapness with which they can be quarried and crushed when compared with other stone suitable for this purpose. The stone should be crushed so that it will pass a two and one-half inch and lodge on a three-quarter inch ring. The stone can be packed very tightly under the sleepers, and should be dressed with "fines" or screenings to occupy the large number of spaces between the stone. Most any variety of calcareous stone may be used for dressing, the purpose of which is to form a more compact mass attained through the filling of the empty spaces. The

12

GEOLOGICAL SURVEY OF GEORGIA

sUiceous and semi-crystalline limestone as well as the bolo-crystalline marbles of Georgia possess a high .crushing strength making them eminently suitable for use as ballast.
Contrete.-Limestone crushed for use in concrete should be free from excessiv~ amounts of dust and should vary somewhat in size and shape to assist in close packing. It should all pass a one-quarter inch i-irig. The crushed stone is mi~ed with cement and sand and the
I
value of the stone depends on its strength, durability, size, shape, etc. The limestones and dolomites of North Georgia, with the exception of those of extremely argillaceous character, can be used for concrete construction.
Flooring.~Limeston~s and dolomites which possess a fine crystalline texture and take a good polish are crushed and mixed with white Portland cement for flooring.
The Cambrian fine: crystalline white dolomitic marble of Fannin, Gilmer, Pickens, and Cherokee counties are entirely suitable for this use. At the present time they are only being developed in Pickens county. The preparation of the stone is a~ follows:
':nhe rock is fed into a crusher a:nd the crushed r0tk is passed over screens to separate the dust. It is then fed into a .gyratory crusher where it is broken into many sizes. It is put on the market in sizes
1, 2, 3, etc.> No. 1 passing through 14.,.inch ; No. 2, over %-inch ; and
No. 3, over 1f2~inch ring.
BUILDING STONES
The most important calcareous rocks quarried in Georgia and used for building purposes are the white and vari-colored crysta'lline Cambrian marbles of Pickens County1 Marbles also occur in Fannin, Gilmer, arid Cherokee counties.
The Cambrian limestones of the Appalachian Valley are seldom used for building on account of the clayey impurities present and the usual large amount o,f secondary calcite developed in stringers throughout the limestone.
The Knox dolomite of Cambro-Ordovician age has not been used
1McCallie, S. w., The Marbles of Georgia: Bull. Geol. Survey of Ga. No. 1, 19.07.

LIMESTONES, CLAYS, SHALES .AND SLATES

13

except for local purposes. The high cost of quarrying this heavy bedded and massive limestone will probably prevent its use as a building stone.
The Chickamauga limestones of Ordovician age are the only limestones of the Appalachian Valley region of Georgia that have been widely used for building. At Chickamauga, Walker County, the limestones of the Chickamauga formation have been pretty extensively quarried for trimmings, door steps, foundations, curbing, construction of buildings, and by the United States Government in culvert construction on National roads in the vicinity of Chattanooga. All sizes of stone can be obtained in the same quarry, due to the variation in thickness of the bedding and the numerous joints developed perpendicular to stratification. The limestone splits parallel to the bedding and along these joint planes. The Silurian limestones (Rockwood formation) are always thin bedded and never available for building purposes.
The Floyd and Bangor formations of Mississippian (Lower Carboniferous) age contain the most important and promising building stone of northwest Georgia. The limestones of the Floyd formation seldom exceed 100 feet in thickness, while those of the Bangor formation sometimes reach a thickness of 800 or 900 feet. These limestones contain oolitic, crinoidal, and crystalline beds. The geologic conditions nearness to markets, railroad facilities, and general favorable conditions of quarrying are often such as to make these limestones of economic value.
MORTARS .AND PLASTERS
Both high-calcium and dolomitic limes are used in preparing mortars and plasters. The fact that slaked lime mixed with sand hardens when exposed to the atmosphere, together with the ease of preparation, plasticity and adhesive properties, makes it valuable for use, both in interior and exterior construction. The sand prevents shrinkage and indirectly causes a greater strength by aiding the mass in the absorption of carbon dioxide by the lime, forming the carbonate.
Hydrated lime is now extensively used as a mixture with natural

14

.GEOLOGICAL SURVEY OF GEORGIA

and PortlaiJ.d cement for use as mortar. When lime is added up to 30 per cent. it adds strength to the cement and makes it more impervious.
All limes used with sand for mortars and plasters should be thoroughly slaked. If the lime is not thoroughly slaked it will contain some quicklime and the absorption of moisture by the quicklime causes the mortar or plaster to expand and crack.
AGRICULTURAL PuRPOSES
High-calcium. and magnesium limes are preferable for agricultural purposes. High-calcium limes are used on soils containing considerable magnesia, while the magnesium limes are more suitable for soils free of this constituent. Argillaceous limes are only used when high-calcium and magnesium limes ar~ not available, for the agriculturi:st desires the greatest percentage of calcareous materials 1?0ssible in the stone to perform the chemical and physical functions in a soil already containing sufficient silica and alumina.
Chemical function of time.-Phosphoric acid, potash, and lime are the principal constituents in the soil that need constant replacement. When lime is applied to the soil it un:ites with silica and alumina, which are the two most abundant soil constituents, and also with other soil substances. Lime makes potash available for plants, and it reacts with the inert compounds of iron and alumina, which may be combined with phosphoric acid and causes the phosphorus to become. available for plant food. It also -reacts with organic compounds and manures and liberates ammonia and neutralizes organic acids which result from organic decomposition.
Physical effect.-The physical effect of lime on the soil which is largely due to chemical reactions that have taken place betwe~n lime and certain soil constituents, is often of as much value to the plant as the indirect effect of fertilization due to the liberation of plant food. The physical characteristics of soil.such as texture, porosity, character Of soil particles, which increases or decreases the capillarity, etc., are of considerable importance in determining the value of soils for agricultural purposes.

LIMESTONES, CLAYS, SHALES AND SLATES

15

Lime reduces the plasticity of clayey soils and makes the clay more
porous and through a greater porosity it promotes nitrification. Lime
furthermore on sandy soils, by chemical combination, forms silicates and performs the function of a cementing material, bringing the soil particles closer together, thus diminishing the porosity of the sandy soil.
It is especially desired to emphasize the fact that residual soils derived from limestone are usually as much in need of lime as those derived from sandstones, shales, or crystalline rocks. This can best be brought to the attention of the agriculturist by the analyses of a calcareous rock and a soil derived from it, copies of which are here given:
Analyses of Knox Dolo,mite1 and Soils in the Vicinity of Cave Springs, Georgia.

Constituents determined.

Knox dolomite.

Soils.

Calcium carbonate (CaCOa) _______________________ _ Magnesium carbonate (MgCOa)- ______ ------ ___ -- __ Alumina (AhOa)- _--- ___ ----- . ------- -----------Iron oxide (Fe20a)------ _--- ___ ---------------- __ Silica (Si02)-- __ -------------------------- -- ---- --

52.05 36.32 2.68 2.10
6.47

} .01 to 2.00 } 6.00to 16.00 60.00 to 80.00 .

In the process of rock disintegration, the calcareous matter is dissolved out of the rocks and is carried away in solution, thus forming soils by the accumulation of silica and alumina with a small percentage of other constituents. It is necessary to apply lime so that it will be uniformly distributed in th~ soil, in order to perform the physical and chemical functions above mentioned.
Amount of lime to be used.-The number of bushels of lime to be used per acre and the frequency of application depend on the character of the soil. A number of interesting results were brought out at the Maryland Agricultural Experiment Station and presented in their Bulletin No. 110, p. 9. The results of their experimental work shows

l.Spencer, J. W., Paleozoic Group of Georgia.: Geol. Survey of Ga., 1893.

16

GEOLOGICAL SURVEY OF GEORGIA

that, all things taken into- consideration, annual application of twenty bushels of lime to the acre is proportionally more effective than 50 to

60 bushels.

LITHOGRA.Pmc STONE

Lithographic stone is a fine grained, homogeneous limestone of

uniform
'

chemi-cal.

composition.

It may vary in color, which is not

such an important factor as constant physical character. The litho-

graphic stones in practical use contain a low percentage of magnesia.

The effect of acid on calcium and magnesium is so different that if the

stone contains any considerable amount o.f magnesia it can not be

evenly etched.

The following .chemical analyses show the variation in chemical character of some lithographic stones1 :
AnalY'ses of Lithographic Stones.

Constituents determined.
'

Branden- Solenhofen Mitchell burg, Ky. Bavaria.. Co., Iowa.

Insoluble in hydrochloric acidSilica (SiOz) _________________ ----------

Alumina and iron oxide (AlzOa +FezOa) Lime (CaO) ~ _________ ~ ____________ . _ . -

Magnesia (MgO) _______________ . _. _____

Soluble iir:hydrochloric acid~

-

Alumina (A1z0a)-~------------------Ferrous oxide (FeO) ____________ --------

Magnesia (Mgo) ______ '--- __ ...,- __________

Lime .(CaO)-----~--------------------Soda (NazO) ____ ---- __ -------- -- -- -- -Potash (K20) ___ ----'- --------- -~ -- ---Humus ____ -----------.-~-------'----- __ Hygroscopic water (HzO) _____ ------ ____
Water of composition (H20) _____________

Carbon anhydride (C02)-------- __ ---- __ Sulphuric anhydride (SOa) ____________ ._

3.15 .45 .09
-----
.13 .31 6.75 44.76 .13
--- --
.41 .47 43.06
-----

1.15 .22
tr.
-----
.23 .26 .56 53.80 .07
__, ___
.23 .69 42.69
----- '"

.78 tr. -----
--. --
.12
-----
.07 I 54.91
.18
.11 -----
.35 43.16 tr.

Total____ -'- ____ "__________________ . 99.71

99.90

99.68

Mechanical admixtures of silica and alumina are objectionable, as

1Hoen, A. B., Iowa Geological Survey; Vol. XITI, 1902; p. 846.

LIMESTONES, CLAYS, SHALES AND SLATES

17

they leave a roughened surface when the limestone is etched. Calcite in veins or distributed irregularly throughout the stone is also obj-ectionable. A cross section perpendicular to the plane of stratification shows the character of the texture. The hardness required to suit the engraver is best determined by the engraver himself. Absorption and specific gravity tests are important.
Lithographic stone is not confined to any geologic formation, but may be found in any sedimentary rocks where the conditions of sedimentation were satisfied.
PAPER MANUF.ACTURE
Paper is largely manufactured from two types of material: (1) straw, rags, etc.; or (2) wood pulp. In the manufacture of paper from straw and rags, lime oxide is used to dissolve any fatty impurities which may be present. The lime oxide should be derived from a highcalcium limestone.
In the manufacture of paper from wood pulp, there are two important methods of reducing the wood to pul.p: (1) the soda process; and (2) the sulphite process. High-calcium lime is used in the former process while dolomitic lime is used in the latter.
LEATHER M.ANUF.ACTURE
High-calcium lime, low in silica, alumina and iron, is preferable in the tanning process of hides and skins. Lime in solution as "milk of lime" is used to remove the flesh adhering to the skins, to loosen the hair, and to soften an4 swell the hides for the further processes to which they are subjected.
SUG.AR M.ANUF.ACTURE
Calcium oxide in solution in the form of "milk of lime," used in
the manufacture of sugar, must be derived from a high-calcium lime-
stone, low in silica, alumina, and iron, and especially low in magnesia. Magnesia forms a soluble compound with sugar, while calcium forms an insolU:~le tricalcium sucrate which may be separated by filtering and later when carbon dioxide gas is passed into solution it is broken down into calcium carbonate and a solution of sugar.

18

G~OLOGIC..AL SURVEY OF GEORGIA

MANUFACTURE OI!' GLUE
In the manufacture of glue, organic animal refuse is :treated with tinslaked or lime hydrate ill: the form of "milk of lime" to remove the oils, flesh, and blood, and to disintegrate the tissues and to soften the marrow..
SoAP .AND CANDLES ('_'
.High-calcium limes with a small quantity~ ;of. magnesia are used with sodium carbonate to reduce it to caustic S.Qdfl. which is used with fats to form soap. By the addition of sulphur,ic p.cid the ~ree organic acids are separated and are used in the manufacture of candles.
GROUND LIMESTONE
Agricu. ltural p.urposes.-Gr.ound limestone is used to perform the same. functions in soils as; burnt lime. The chemical activity of the ground limestone will depend on the degree of fineness of the particles. For agricultural purposes they are usually ground to a fineness of 60 to 70 mesh. Ground limestone can be applied at any season of the year.. It can be equally disti-ibuted on or into the soil and the ."burning;'~ which may result from the excess of slaked lime due to the crude method of distributing it upon the surface; is not likely to occur.
Lime is also used largely for many purposes which have not been mentioned above. Among the more important uses are: the manufacture of sand-lime brick, slag cement, pottery, hydrating agents, disinfecting compounds, etc.
BURNING 0 LIMESTONES.
The high-calcium, magnesium and dolomitic limes are all produced in the same general way, namely, by the decarbonation of limestone. The character of the resultant product depends largely on the chemical composition of the calcined rock. High-argillaceous limestones are seldom used for lirrie, but more especially in the manufacture of the complex ce~ents. The chemical reactions which take place in the bu~ing o1f each variety will be discussed under the classification of limes. In the manufacture of quicklime, the carbon dioxide must be driven from the limestone, the water in the limestone must be evaporated and the stone must be heated to its dissociation temperature.

LIMESTONES, CL.AYS, SH.ALES .AND SL.ATES

19

The dissociation temperature varies ior each variety of limestone and also in two limestones of the same chemical composition, due to differences in texture, hardness, compactness, etc. Water is often added in the burning process forming when heated steam, which, in association with the carbon dioxide given off by the limestone, still further aids in the dissociation of the stone.
The types of kilns most used today in burning limestone are the intermittent and the continuous kilns which are here described.
INTERMITTENT KILNS
Intermittent kilns are vertical with mixed feed. After the kiln is charged, burned, and cooled, the lime is drawn. While this method of manufacture is still in use in the rural districts in some localities, it is regarded today as distinctly primitive. '
CONTINUOUS KiLNS
In all of the continuous kilns, the burnt lime is withdr~wn from below while the limestone is added at the top and there is no interruption in the production, unless so desire.d by the operator. These kilns are of four types: (1) vertical kilns with mixed feed; (2') vertical kilns with separate feed; (3) ring or chamber kilns; (4) rotary kilns.
Vertical kilns with mixed feed.-These are of many types, and on account of their ease of construction they are usually made in the vicinity in which the lime is manufactured. They vary from square or bottle-shaped stone kilns to those made of iron or steel plates and lined in the interior with fire-brick. The feeding of the kiln takes place from the top where first a layer of coal and then a layer of limestone is added and so on alternately and continuously, or at regular intervals. A fire is started at the bottom and as it works its way up, the limestone is calcined and is drawn at the bottom. The manufacture of lime by this process has the following advantages: (1) construction is cheaper .than separate feed kilns or chambe_r or ring kilns; (2) less amount of fuel is necessa_ry to burn the lime; (3) the yield is larger for the same size of kiln. The lime is usually of lower grade however than that which is burnt in separate feed kilns, due to admixture of ash and clinker with lime.

20

GEOLOGICAL SURVEY OF GEORGIA

V e1tical kilns with separate, feed.-In these kilns the hot fue! gasses, only, come in contact with the limestone, which is fed in at the top while the fuel which consists of coal or wood, is fed into fire boxes which are usually set into the walls of stone kilns, while in the more modern iron and steel kilns, the fuel is burnt in horizontal furnaces from two to four in number built out from the kiln above the drawing pan. Producer gas is also used.
Ring or chamber kilns.-The Hoffman kiln1 is the best known type of the ring or chamber kiln, and while it has been used extensively in Germany for the manufacture of lime as well as Portland cement and brick, it has not come into use in this country. The fuel consumption is low in comparison with the vertical kiln; however, it requires skilled labor for each operation.
Rotary kilns.-The New York li~e c~mpany at Natural Bridge,
N. Y., was the first company in this country to carry on the successful manufacture of lime in the rotary, kiln. This method of manufacture
results in a lime which is superior in many ways to lime burned in the
vertical kiln and many difficulties of burning are done away with. The following references are cited for those interested in the manufacture of litne in the rotary kiln :
Rock Products, V.ol. IV, No. 1, p. 35. Flrase-h, .Mineral Industry, Vol. VII, p. 491.
Spa,c$.:man, Henry 0., Rock Pr:oduct's, Vol. TV, No. 21 p. 38.
Rock Products, Vol. IV, No. 5, p. 45.
FUEL USED IN LIME BURNING
The two principal materials used in Georgia for lime burning are .wood and coal. Wood is best suited technically. With good wood, more lime, as a rule, can be produced than with coal; however, the cost of wood today is usually slightly greater per ton of lime produced.
Coal is gradually replacing wood for the burning of limestone, due to the scarcity and high cost of wood in most localities. With the modern appliances for burning coal the many .objections to its use which formerly existed are done away with.
The cost of burning depends on: (1) the chemical character of
1Frasch, Mineral Industry, Vol. VII, p. 491.

LIMESTONES, CLAYS, SHALES AND SLATES

21

the limestone, whether high-calcium, dolomitic, or argillaceous; (2) the physical character of the rock, nature of crystallinity, texture, degree of consolidation, etc. ; ( 3) the kind of fuel used, quality, and cost ; (4) the skill of. the burners.
Few lime burners keep any accurate account of the amou~t of fuel consumed per ton of lime. Statistics are not available on the cost of production of lime in this State; however, for those interested in the character of fuels used in other states and the cost of production, the following references are cited :
1905--Grimsley, G. P., Clays, Limestones, Cements: W. Va. Geol. Snrvey, Vol. ill, 1905, pp. 360-368 'and 383-384.
1906-0rton, Edward., and Pepple, Samuel Vernon, Limestones, Lime and Sand-lime Brick: Geol. Survey of Ohio, 4th ser. Bulls. 4 and 5, 1906, pp. 291-293.
1907-Eckel, Edwin C., Cements, Limes and Plasters: 1907, pp. 98-112. 1907-Bueib.ler, H. A., The Lime and Cemen,t Resources of Missouri: Mo. Bureau of Geology & Mines, Vol. VI, 2nd ser., 1907, pp. 37-43.
CLbSSil'IOATl!ON OF COMMON LIMES
The common limes are classified, according to their chemical composition, as follows: high-calcium limes, magnesian limes, dolomitic limes, dolomites, and argillaceous limes.
HIGH-CALCIUM LIMES
When limestones contain less than 5 per cent. of magnesium carbonate and a small percentage of other impurities they produce, when decarbonated, a high-calcium lime. The chemical changes which take place in a theoretically pure limestone in the burning process are the following!
Limestone (CaC03) +heat= quicklime (CaO) +carbon dioxide (C02 ).
If the quicklime is exposed to the atmosphere it will absorb water and form hydrated calcium oxide (Ca(OH) 2 ). The same result can be had by the addition of water: CaO + H 20=Ca(OH) 2 After the lime has "slaked" and is further exposed to the atmosphere it takes up carbon dioxide (C02 ) and the chemical reaction may be expressed as follows :
Calcium hydrate (Ca(OH) 2 ) +carbon dioxide (C02 ) =calcium

22

GEOLOGICAL SURVEY OF GEORGIA

carbonate (CaC03 ) +water (H20), thus the calcium oxide by combination with the carbon dioxide of the air returns to the carbonate and the water evaporates into the air. High-calcium limes are known to the mixer as "strong limes," on account of the fact that they will carry more sand than other. limes. A theoretically pure limestone carries 56 parts by weight of calcium oxide (CaO) a,nd 44 parts by weight of carbGm dioxide (C02 ), and if we assume that decarbonation is complete we may express the result as follows:
100 pounds calcium carbonate (CaC03 ) +heat== 56 pounds of quicklime (CaO)+ 44 pounds of carbon dioxide (C02 ).
MAGNESIAN UMES
When a limestorte contains more than 5 per cent. and less than 30 per cent. of magnesium ~arbonate it produces, when burnt, a magnesian lime. The carbon dioxide is driven off precisely as in, a theotretically pure high-calcium lime; however, there are some differences in burning and usually less heat is required for decarbonation.

DOLOMITIC LIMES AND DOLOMITES

I

.

Most of the commercial limes carrying J:I:lagnesia approach the com-

position of a dolomite. When a dolomite is calcined, the amount of

calcium and magnesium oxides in 100 pounds of dolomite can be

d.etermin. ed and expressed in a commercial formula as follows : . Calcium carbonate ,(CaC03 ) 54.3 per: cent.+ Magnesium carbonate
(MgC03 ) 45.7 per cent.= a theoretical dolomite.

Calcium carbonate is made up of 56 per cent. calcium oxide (CaO)

and 44 per cent. carbon dioxide (C02 ). If we now assume that decarbonation is complete, the loss of carbon dioxide on calcination, due to

the calcium carbonate, will be 54.3 X 44 = 23.9 per cent. carbon diox-

ide (C02 ), and the residue of calcium oxide due to the calcium car-

bonate will be 30.4 per cent.

'

I

Magnesium cC).rbonate contains 48.0 per cent. magnesium oxide

(MgO) and 52. per cent. carbon dioxide (C02 ), hence 45.7 X .52= 23.7 carbon dioxide (C02 ) and the residue of Magnesium oxide (MgO), due to the magnesium carbonate, will be 22 per cent. The

LIMESTONES, CLAYS, SHALES AND SLATES

23

total composition of the original rock may be expressed as follows: The original. rock contains in 100 lbs._______ 30.4 lbs. CaO and -------------------------------- 22.0 " MgO

making a total of______________________ 52.4 " CaO and MgO contained in 100 lbs. of dolomite.
.ARGILLACEOUS LIMES
Limestones high in silica and .alumina are seldom burned for common lime, but are extensively used in the manufacture of complex hydraulic cements.
HYDRATED LIMES
When quicklime is exposed to the atmosphere for any length of time or if water is added the lime combines with the water to form slaked or hydrated lime. The chemical reaction is as follows :
Lime (CaO) +water (H20) =lime hydrate (Ca(OH2). It has been realized for many years that when quicklime (CaO) is slaked by the ordinary laborer, too much or too little water is added and an unsatisfactory product is likely to result. The quicklime generates heat on slaking, and if too little water is added "burning" is likely to occur, while too much water is equally as objectionable. It is almost impossible for the day laborer to mix the quicklime and water in the proper proportions. The results of a poorly mixed lime hydrate may cause "pitting" and cracking of the mortar. Lime hydrate can now be carefully manufactured and the unsatisfactory results mentioned above done away with.
METHOD OF MANUFACTURE
(1) The carbon dioxide must be driven from the limestone as in any ordinary process in the manufacture of quicklime (CaO). (2) The quicklime must be ground to a fairly uniform small size. In some plants it is crushed to about one inch while in others it is reduced to one-half inch size or to a fine powder. (3) The ground quicklime must be intimately mixed with sufficient water. There are a number of methods used for hydrating the quicklime; however, the principal object of them all is to thoroughly and intimately mix the quicklime

24

GEOLOGICAL SURV;EY OF GEORGIA

and water. The amount of the water to be added depends on the chemical character of the quicklime. Different amounts are added to a high-calcium, a dolomitic or a high-magnesium lime, and the amount to be added in each case is determined by exp~rience. (4) Any unhydrated lumps or cores must be separated by screening from the fine slaked lime.
The very fine hydrated lime is packed in bags and sold according to the standards adopted by ~he hydrated lime manufacturers of the United States1 The cost and equipment of a hydrated lime plant depends on the character of the stone and the method of manufacture.
ADVANTAGES OF HYDRATED LIME
Hydrated lime is characterized by the. foHowing advantages: (1) It will not. air slake, for it has taken up already the necessary amount
of water of combination. It will 'therefore keep for a long time in
barrels, sacks, or paper bags. As it does not absorb water, there is no danger of expansion which takes place in quicldime (Ca6), due to the absorption of water front the atmosphere. It can be shipped by water and there is no d<;~.nger of heat being generated and consequent fire. (2') It does not contain, grit or "core"-this is separated by screening. (3) "PoPping" and cracking of mortars made with hydrated lime are not so likely to occur as. from lime-hydrate roughly prepared. (4) It can be mixed uniformly with cement and is used for the purpose of water-proofing the latter or to ma:ke a more easily troweled mortar.
USES OF HYDRATED LIME
The more important uses of hydrated lime are : for purifying water, washing boilers, iron moulding, agricultural purposes, coM water p~ints, glass industry, a dry spray and in solution with sulphur for fruit trees, etc. Hydrated lii:ne mixed with natut:al cements and gypsum .makes a slow setting, but very hard, plaster. Hydrated lime added to and ground with natural cement rock adds greatly to the strength of the cement mortar2 By the addition of hydrated lime to Portland cement
a.Engineering News, Sept. 8, 1904, Vol. 52, p. 220. 2Bleininger, .A;;- V., The Manufacture of Hydraulic' Cements: Geological Survey o:f Ohio, Bull. 8, 4th ser., 1904, p. 191.

LIMESTONES, CLAYS, SHALES AND SLATES

25

mortars, better working properties, a greater density, and waterproofing qualities are the result. Hydrated lime as a disinfectant is equally as good as the quicklime. It can be put up in small packages for sale and can be kept almost indefinitely. Hydrated lime is used for many other purposes.

LITERATURE ON HYDRATED LIME

1903-Brig1ham, S. Y., The Manufa,cture and Properties of Hydrate of

Lime; Engineering News, Vol. 50, Aug. 27, 1903, pp. 177-179. 1903~Warner, C., Hydrated Lime: Engineering News, Vol. 50, Oct. 8,

1903, pp. 320-321.

1903-Warner, C., Strength Tests of Mixtures of Hydrated lime arid

Port1and Cement: Engineering News, Vol. 50, Dec. 17, 1903, p. 544.

1904-Peppel, S. V., Lime Experiments: Rock Products, Vol. 3, April-

May, 1904, p. 17.

1904-Brigham, S. Y., Hydrated Lime: EngineeLring News, Vol. 50, June 9,

1904, p. 543.

1904-W,arner, C., Standards Adopted by Manufacturers of Hydrated Lime:

Engineering News, Vol. 52, .Sept. 8, 1904, p. 220.

.

1906-Drton; Edward, Jr., and Peppel, Samuel Vernon, The Limestone Re-

soruces and the Lime Industry of Ohio: Bull. Geol. Survey of Ohio No. 4, 4th

ser., July, 1906.

1910-Lazell, E. W., Comparative Tests of Lime Mortar, Both Tension

.and Compression-Hydrated Lime and Sand-Cement Lime and Sand: Rock

Products, Vol. X, No. 3, Sept. 22, 1910, pp. 48-51.

1910-Matthews, E. B., and Gr,asty, J. S., The Limestones of Maryland:

Maryland Geo1. Survey, Vol. VIII, pt. 3, 1910, pp. 225-229.

CLAYS, SHALES AND SLATES
CLAYS
' ORIGIN
Clays consist of a heterogeneous mixture of rock constituents the nature of which depends upon the character of the material from which the clay is derived. Clays are all of secondary origin and are derived from either igneous, metamorphic, or sedimentary rocks, resulting from the disintegration of these rocks by the normal processes of weathering and erosion. Clays may be either residual or transported. Residual clays are those derived in situ from the underlying rocks. Transported clays consist of stream, glacial, lacustrian, marine, and estuarine deposits.

.26

GEOLOGIC.AL SURVfEJ! OF. GEORGIA

PHYSICA;L CHARA:CTER

The residual clays, resulting from the decomposition of igneous,

.metamorphic and sedimentary .rooks, are seldom uniform in their physi-

cal charact~r and usually contain fragments of siliceous nodules, com-

cretions, etc., which may be interspersed throughout the original rocks.

The transported clays which consist of stream deposits vary from fine

to coarse-grained clays, but are seldom uniform over a sufficient thick-

ness for economic,use in the manufacture of cement.
'
CHEMICAL'CHARACTER

The residual and transported stream clays of North Georgia and

the consolidated shales and slates may all be of similar'chemical char-

acter. However, some chemical constituent usually :predominates and

they may be classified as siliceous, aluminous, ferruginous, and car-

bonaceous.

SHALES AND SLATES

ORIGIN
Shales consist of fine muds or clays whi~h have been -at some time

deposited in water and have been subsequently subjected to pressure

and consolidated into r.ocks, possessing characteristic cleavage or other

structures. The P.ressure was due either to the weight of the over-

lying rock formed by subsequent deposition, to forces to which these

rocks were subjected during mountain f01"ming periods of the earth's

crust, or to both of these causes combined. Under further pressure

and increased temperature the character and structure of the shale

were altered, chemical changes took place, the rock underwent a re-

crystallization, perfect cleavage and fissility developed and the shales

were changed into slates.

. PHYSICAL CHARACTER

Shales vary in color from cream and white to black, depending on

' the presence or absence of carbonaceous matter and variations in chemi-

cal composition.

.

In texture, the shales vary from fine-grained, close, compact; con-

solidated clays to semi-crystalline and crystalline slates. Shales are

characterized by their fissile nature which is usually parallel to the



LIMESTONES, CLAYS, SHALES AND SLATES

27

original bedding while the cleavage of a slate may be at any angle to the stratification. The weathering of shales is often a criterion of their chemical composition. Shales weather splintery, hacldy, pisolitic-like, etc. Argillaceous shales usually break down at once, on exposure; to clays, while the more siliceous varieties weather hackly or splintery, and when they are highly crystalline, as in commercial slates, they retain their fissile character when exposed to the weather for a long period of time.
Slates are quite deficient in plasticity, while shales are usually somewhat deficient; however, shales which have been superficially disintegrated by weathering agencies often contain sufficient plasticity for the manufacture of brick of superior quality.
CHEMICAL CHARACTER
The chemical composition of shales varies between rather wide limits. Silica and alumina are the most abundant constituents present, while lime, magnesia, manganese, iron, titanium, and the alkalies are present in smaller amounts. The term shale signifies no specific chemical composition ; however, as a geologic term it. signifies fineness and uniformity of composition over a unit of uniform lithologic similarity.
CLASSIFICATION OF SHALES
Shales may be described as siliceous, aluminous, ferruginous, calcareous, and carbonaceous.
Siliceous shales.-Distinctly siliceous shales of extremely fine grain are rare. They represent the transition stage between the formation of normal shales and sandstones.
Aluminous shales.-Shales with a relatively high content of alumina in comparison to silica are referred to as aluminous shales.
Ferruginous shales.-Unweathered shales usually contain iron in the form of ferrous carbonate which gives to the shale a dark gray to bluish gray color; the carbonate Lecomes oxidized in the weathered shale to the ferric oxide, which gives the shale a reddish or brownish appearance. Iron may occur as ferrous carbonate in the form of concretions. When the concretions occur in large quantity or in such a

28

GEOLOGIC.AL SUJJ,VEY OF GEORGI.A

state that they can not be economically separated the shale becomes worthless. for most col'nmercial purposes. Iron is1liable to occur in the form of iron sulphide (iron pyrite) and it is _equally as objectionable as the concretions above mentioned. The iron sulphide is oxidized in the weathered shale to the svlg_lJ,ate and gives a somewhat mottled yellow color to the shales.
Calcareous es,ha.Zes.-, Shal~s~a-rryirtg more than 5 p~r cent. of lime are usually referred to as calcareous. Shales wlikh rest coilformably upof! limestone and thin bedded shales interstratified with limestones are usually calcareou~. A shale may owe its content of lime both to organic and inorganic agencies.
Carbonaceous shales.-These shales are char<+cteri4ed by the presence of carbonaceous matter which may vary from a trace to at least 14 per cent. The shale is dark brown to black in cqlor and where the
content of iron' is high the color ~s often green.

HYDRAULIC LIMES, NATURAL AND PORTLAND CE..MENTS
THE . RELATION OF HYDRAULIC LIMES, NATURAL AND PORTLAND CEMENTS
Hydraulic limes, natural cement and Portland cement differ from one another in physical and ch~mical character. Their peculiar characteristics are due as much to their physical condition, resulting from a definite process of manufacture, as to their chemical composition. Matthews and Grasty1 comment as follows on the classification of these compounds:
Nearly all formulas have supposed that cements and hy<kaulic limes owe their hydraulic properties to definite chemical compounds. The most recent investigations which have been made upon this class Of materials tend to prove that they are not definite compounds, but wha.t are known to physical chemists .as solid so!l.utions, and are similar in chatracter to blast furnace slags, steel an.d alloys. It would seem better, therefore, to classify these compounds accol'ding to their physical properties an.d method of manufacture, rather than according to their chemical chamcteristics. Such a classification would be tJ:J.e following:
J Common lime: Limes made by burning relatively pure limestones, which, when mixed with water, slake and show no hydrulic properties.
2. Hydraulic limes: Limes made by burning impure limestones at a low temperature which slake with water, but which show hydraulic properties.
3. Natural cements: Cements which are made by burning impure limesstones at a low temperature (insu:ffjcient to vitrify) which do not slake with water, but require to be ground in order to convert them into a hydraulic cement.
4. Portland cement: Hydraulic cements which are made by heating to incipient vitrification a mixture of argillaceous and calcatreous substances, which product does not slake with water, but upon grinding forms a.n energetic hydraulic cement.
5. Puzzol.an cement: Gements which are formed by incorporating slaked lime with a finely g.round slag or volcanic ash.
lThe Limestones of Maryland, with special reference to their use in the manu. facture of cement: Special Publication Md. Geol. Survey, Vol. :VIII, pt. 3, 1910, pp. 270-271.

30

GEOLOGICAL SURVEY OF GEORGIA

The hydraulic limes are burned at a low temperature so that the

resultant material will contain sufficient free lime to slake the entire

'

.

. clinker when water is added. The taw materials used in the manu-

facture of natural cements are burned to a higher temperature than

the hydraulic limes, that is, to a temperature of.900-l,OO.O degrees cen-

tigrade, so that the carbon dioxide .is driven off and the calcium and

magnesium oxides combine with the argillaceous ingredients. The

natural cements which contai1,1 a low content of argillaceous material

are mo;:te .nea.rly like the hydraulic limes, while those with a high con-

tent of silica and alumina more closely approach a Portland cement.

The fine grinding and burning of Portland cement mixtures to incipient

vitrification, followed by ,the fi:ne grinding of. the clinker, results in a

cement entirely distinct from the hydraulic limes and natural cements.

Portland cements s~t slo;vy~r than natural cements and attain a higher

tensile and crushing sttength.

HYD!t.AULIC LIMES
Hydraulic limes occupy art intennediate position between what are known as simple limes, which show no hydraulic properties, and the complex cements, which are eminently hydraulic.
Hydraulic limes are made by burning siliceous or argillaceous limestones and at times a magnesian limestone _(in the, manufacture of feebly hydraulic limes) at a moderate temperature. While the raw materials used in the manufacture of hydraulic limes occur in this
v,
country, but little has been manufactured; however, a considerable quantity of hydrauli~ lime (including Grappier cements) is imported annually. Its chara.cteristic liglJ.t color, due to the low content of iron and soluble salts, has made it valuable, especially in interior work. The white cements which are now being manufactured in the United States are taking the place of the foreign hydraulic limes.
The hydraulic limes have been classified by Eckel1 as: (l) eminently hydraulic limes; and (2) feebly hydraulic limes.
1Eckel, Edwin C., Cements, Limes and Plasters, 1907.

HYDE.A.VLIC LIMES, N.A.TVE.A.L AND FOBTLAND CEMENTS 31

EMINENTLY HYDRAULIC LIMES
Raw materials.-The more important constituents of the limestones used in actual practice vary between the following limits :
Per Cent. Calcium carbonate (Ga003) 3 9 - 45 Silica (SiOz) . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . 13 - 17
Alumina (AlzOa) .. . 1 _
J Ferric Oxide (FezOs) ......... ........ . ... 0 3

The calcined stone must satisfy the following conditions: (1) it must contain sufficient free lime to slake the. entire clinker when water is added. (2) Just sufficient free lime should be present to effect the disintegration of the clinker. (3) Free silica and alumina should not be present in the clinker.
Grappier cements.-These cements are made by the fine grinding of the underburned and overburned material resulting in the manufacture of eminently hydraulic limes. Lafarge non-staining cement made in France is a well known Grappier cement.

FEEBLY HYDRAULIC LIMES

Raw materials.-The more important constituents of the limestones

used in actual practice vary between the following limits:

Per Cent.

Lime and Magnesia (CaD+ MgO) ................. 45-48

Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 - 36

Silica (Si02)
Alumina (Al20a) ......... l
Ferric Oxide (Fe20a) .......................... j

5- 8 4- 7

The calcined stone contains a large excess of free lime, reducing the hydraulic property to almost nil.
Selenitic lime.-The feebly hydraulic limes form the base for the manufacture of selenitic limes, often known as Scott's cement, which consist primarily of lime (CaO) plus a small amount of sulphur trioxide (803 )
. BURNING OF HYDRAULIC LIMES
Hydraulic limes are burned in kilns similar to the types used in the manufacture of simple limes. The argillaceous character of the

32

GEOLOGICAL SURVEY OF GEORGIA

rock necessitates a higher temperature in the kiln for complete decar-
bonation than a common high-calcium OJ dolomitic limestone.
THE EVOLUTION OF .CEMENTS
It has b~en recognized since very early times that the product resulting from the burning of limestone when mixed with sand and water would 'Produce an ordinary lime mortar. Lime mortar, however, would !not harden under- .water. A material was needed for construction which would harden under water as well as in air and such a material now knOtwn as -"natural cement" was used by the ancient Egyptians, the Greeks, and the Romans. Cummings1 says :
The fact is, that the history of natural rock cement rea,ches so far back into the early .ages, th~t it is impossible to learn precise_ly the date of its first fabrieoation.' But we do kn.ow that the ancient Egyptians made natural cement foU!r thousand years ago which would set and harden under water. The Romans over two thousand years ago made most excellent natu~al cement, and used it in enormous quantities for sewers, water pipes, bathing fourutains, piers; breakwaters, :aqueducts, etc.
Many American writers have stated that the pyramids of Egypt were built of cement. In a letter from Athens, Greece, to the writer, Dr. D. M. Robinson2 says:
The pyramids of Egypt have no cement. They are built of blocks of native sto.n.e and the whole was covered with slabs of marble' The covering w:as long ago removed.
John Aspdin of Leeds, England, originated the name "Portland cement," which he . applied to the resulting product made from limestone and clay after burning and grinding. This material, when it hardened, so closely resembled the stone from Portland, England, that he called it Portland cement. While the name Portland cement has remained, it is today a very different material,, from the cement made by Aspdin. It is generally thought that Aspdin made nothing more than an artificial Roman cement. Portland cement of today is a product; not an invention. It has been produced as the result of years of
. arduous investigations and has reached its present stage of perfection
through the normal process of evolution from the simple to the complex.
1Cumm1ngs, 1Jriah, American Cements, 1898, p. 13. 2Professor of Greek, American School of Classical Studies, Athens, 190-9-1910.

HYDE.ADLIC LIMES, N.Al'DR.AL .AND PORTLAND CEM:ENTS 33
About the year 1818, a great deal of canal construction was going on in the United States and the engineers in charge were on the lookout fot a material which would produce a natural cement. Canvas White; an engineer, found a natural cement rock near Chittenango, Madison County, New York, from which he manufactured a hydraulic cement used in the construction of the Erie canal. This marks the beginning of the cement industry in the United States. Natural cement was found in many other localities soon after this discovery was made by White.
At the time Aspdin made his so-called Portland cement in England in 1824, it had not been recognized that burning the material to incipient vitrification was essential. It is not known definitely at just what time it was recognized as essential for a Portland cement, however, it was known prior to 1859.
In 1875 the Coplay Cement Company, of Coplay, Penn., which company was at that time manufacturing a natural cement, was able through the experimental work of their President, David 0 .. Saylor, to manufacture the first Portland cement made in this country.
Between the years 1875 and 1883, there was little advance in the manufacture of cements in America. Time was necessary to put the American cements on an equal footing with the European Portlands. Since 1890 the increase has been phenominal and the production and growth of natural and Portland cement in the United States can best be seen in the accompanying table No. 1.
NATURAL CB:MENTS
Natural, Roman, and Rosendale cements are all derived from the same class of raw materials and the same general process of manu4 facture is used in their preparation. In the discussion which follows, they are all included under the general term natural cements.
Natural cements consist of those materials resulting from the burn..: ing and subsequent grinding of an argillaceous limestone containing natural compounds or mixtures of those compounds which, when combined, possess hydraulic properties. Natural cements are often referred to as hvdraulic cements. All lime cements are hydraulic.

34

GEOLOGICAL SURVEY OF GEORGIA

R.A.w M.A.TERIALS The raw materials used,in the manufacture of natural cements may be found throughout the sedimentary rocks from the Cambrian to the Recent, and they are widely distributed geographically. The raw materials contain froni.15 to 30 or 40 per cent. of argillaceous material which combines with the lime, and also with the magnesia when p~es ent, to give the cement its hydraulic properties. Magnesia is not an objection<iLble constituent in a natural cement. It hydrates readily when it is calcined at a temperature below 1,000 degrees centigrade, while a highly burned rock containing a high content of magnesia hydrates slowly. The magnesia acts like lime combining with the argillaceous constituents to form silicates and aluminates. In the table below, analyses are presented of natural cement rocks from the more important localities in the Southern States.

COMPOSITION
The wide range of the composition of natural cements is due to difflerences in the character of the raw materials; in the methods of burning, and in the temperature attained, all of which cause differences in the chemical combination of the constituents and in their physical properties.

HYDRAULIC LIMES, N.ATVRAL .AND PORTLAND CEMENTS 35
Analyses of Natural Cement Rocks in the Southern States

Location.

:-s.-... I +0 I I&oI-S~ I ,...._

,........ ceo~

"" .5 ~

c:e9 S<t1 c:::>OO
s 2 ~...._,

:;:::!___.

-<
:;z 00.

CD
~ -~ <'l '"0

_,b >=!

,-.,.

.Q.!J,..~.-....

~CD

CD

.Q

lXl cq

c:e 0

"" o o :><: ~
c:::> Cl) ;::::~
'C""l)' '-"
~

Cl)
;.::1

,....... 0 c:e

...c...:l-0--.
>~g=3'! -:;-bg'lJ :;g

g3

oC+'l =>5'.""_'

_. ~

~;=: z'-c":e

,..qQ
"o8..o'-o"

~

00

_:o...:. :_l_P_. ..CgQ3O~ Z' .." .. 0 ,...., ..., ,.......
p,,..~o...qq,..x:s0Cil)...0.Oa$:; ~<.'l .0;o>=!PO'--oC"''l:.-.~.c2:,e "~.0."...

- ---- -- --- --

Maryland_ Cumberland1 ___ 24.74 16.74 6.30 23.41 4.09 6.18 2.22 -- -- -- --- 22.90 -- --

'---v--"

Maryland_ Hancock2 __ ---- 19.81 7.35 2.41 35.76 2.18 ---- -- -- ---- ----- 31.74

~

Maryland_ Antietama______ 15.97 7.59 23.72 15.60 - - 0. 71 - - -- -- - 34.82

~

Virginia___ Baleony Falls4 __ 17.30 6.18 1.62 29.54 13.05 ---- ---- ---- ---.- 34.17

1 ~~~~~o~85 W VirMginia

74

..---'----..

Shepherdstown5 15.89 5.58 1.0052.74 19.06 4.92 0.31 0.12 ---- ...

Cedar Cli:ff6 ____ 27.86 11.71 .72 40.74 13.95 1.30 ---- ---- -----

Kentucky_ Louisville7 ------ 9.69 2.77 1.95 29.09 15.69 ---- -- -- ---- -- --- 40.14

'---v--"

Geo,gia___ Cement8 - ______ 5.28 Georgia___ Rossv:ille9 _ _ __ _ _ 6. 52 Georgia___1Rossville1 o_____ 122. 93

2.62 \30.6017.25~---. 0.02 0.04 3.83 ---------
0.96 47.98 1.25 ---- ---- tr. 2.58 40.71
4.16 33.80 0.45 ---- 0.03 0.02 10.43 28.18

1Eckel, E. C., Cements, Limes and Plasters, 1907, p. 206. 2Ibid. 3!bid, p. 218. 4lbid, p. 212. ~Grimsley, Geo. P., Clays, Limestones, Cements W. Va. Geol. Survey, VoL III, 1905, p. 500. 6!bid, p. 508. 7"Crown Brand," Hansdale Mill, New Albany Cement Co. Analysis by W. A. Noyes, quoted by Siebenthal, 25th Ann. Rept., Ind. Dept. Geol. & Nat. Res., pp. 880-386. 6From strata of dolomitic limestone used at the present time. 9Limestone. 10Argillaceous limestone locally known as "cement rock." 9 and 10 are burnt separately, then mixed and ground to produce a natural cement.

In the following table are 1lresented analyses of the natural cements

at the more important localities in the Southern states :

36

GEOLOGICAL SURVEY OJJ' GEORGIA

Analyses of Natural Cements in the Southern States

Location.

__...
0

CD
'"0 -~

.'".C.0.D.

. z ,..__
ra o Col
.s .s 0 li!g
g::s ~w.
s2- ~'-"
< 8 - - 00.

..---. OQ

.'.tC.:.D.i

,..c_o_

<ilO ~

~0 ~

~5

~

CD

Iii

..... ..... IDO c:ilr-. - 0 CSD h~bD
Iii'-'
~

Col c:il
;=I Col
~<i.!l:!~1

0 .

.t:.:.:J.s.

..---.
co

..clO

~
'"0,-.
~ Col
oO

,.:&::0;0'-.' Iii'-'

00.

D

....._

!V

0
Col

+<=>ill:'C-l'
~

Maryland ____ Cumberland1 ___ 25.70 12.28 4.22 52.69 1.44 ----- ----- ---------

r

~

Maryland____ Hancock2 ______ 28.02 10.20 8.80 44.48 l.OO 0.50 ----- 7.00
Maryland ____ Antietam3 ______ 33.50 10.44 3.25 29.38 13.37 --- -- 1.15 7.15 Virginia___ --- Balcony Falls4. __ 25.15 8.00 3.28 49.53 13.78 ----- - -- -- 0.26

~

West Virginia Shepherdstown5 33.42 10.04 6.00 32.79 9.59 0.50 ----- ----- ---West Virginia Cedar Cliff6 ____ 27.86 11.71 2.72 40.74 13.95 1.30 -- --- ----- 0.85

~

Kentucky ____ Louisville7 ------ 21.10 7.50 44.40 7.00 .80 ----- 11.18 1.16

~

~

Georgia ______ Cement8 _ ------ 22.58 7.23\ 335 48.18 15.00 ----- ----- 3.66

~

~

Georgia______ Cement9 _______ 19.60 11.60 48.96 18.14 ----- ----- ----- ----

~
Georgia. ___ . _'Rossvillel o_____ 25.89 .6.201 1.99 34.09 1. 59~---- 0.50_~--- ----

IDaw, A. W., .Alnalyst, Mi-n. l!hd,, Vol. 6, p. 96. 2Cummings, Uriah, American, Cements, 1898, p. 36, Round Top hydraulic cement. BRichardson, C., An~Myst, Brickbuilder, Vol. 6, p. 229. 4Cummings, Uriah, American Cements, 1898, p. 36, James River hydraulic cement. 5Ibid, p. 35, Shepherdstown hydraulic cement. GAttix, J. C., Analyst, W. Va. 'Ge<>l. Survey, Vol. III, 1905, p. 503. 7Mineral Industry, Vol; I, -p. 50. scummings, Uriah, Americrun Cements, 1898, p. 35.
DBowron, w. M., Analyst, Eckel, E. C., Cements; Limes & Plasters, 1907, p. 253.
IClark, C. M., Analyst, Supplied by Chickamauga Cement Co.

M.ANUFAC'I'URE
Winning the raw materials.-The raw materials are quarried in open pits or mined. The majority of the materials. used in the manufacture of natural cements, with the exception of those in the Lehigh district of Pennsylvania and New ]ersey, occur in beds six to eight feet in thickness, and on account of the structural conditions and the usual considerable thickness of overlying rocks, are most economically secured by mining.
The argillaceous limestone should be broken into pieces of ap-

HYDRAULIC LIMES, N.ATUE.AL .AND PORTLAND CEMENTS 37
proximately the same dimensions. The more satisfactory method is to pass the rock through crushers. When the rock. is fed into the kiln in uniform sizes a better utiliz:ation of the kiln space is secured and a greater uniformity of burning results. When materials of different size are fed into the kiln the smaller masses will be overburned before the larger ones are thoroughly calcined.
Types of kilns.-Argillaceous limestones used in the manufacture of natural cements can be burnt either in vertical continuous feed kilns or in rotary kilns similar to those used in the manufacture of Portland cement. The general type is the vertical continuous feed kiln much like the ordinary lime kiln, but usually larger. The average size consists of a vertical cylinder ten feet in diameter and 24 feet high, the lower seven feet is funnel shaped, tapering to three feet in diameter and narrowing to a neck through which the calcined rock is drawn. The coal, which consists of either an anthracite or a high grade bituminous variety, is either fed into the kilns with the argillaeous limestone or in alternate layers. This method of adding the fuel necessarily causes irregularity in burning, and the raw materials in close contact with the fuel will probably be overburnt before the Emestone that is not in direct contact with it .is thoroughly calcined. This difficulty could be overcome and the quality of the cement greatly improved by burning the fuel in furnac~s arranged at the bottom and around the vertical kilns.
Burning.-The changes which take vlace in burning an argillaceous limestone consist first in the driving off of carbon dioxide from the calcium and magnesium carbonates and the combination of the resulting calcium and magnesium oxides with the argillaceous materials to form silicates. Magnesium carbonates decompose at a lower temperature 'than calcium carbonates. Investigations on the temperature of burning of raw materials for natural cements were carried on by Bleininger1 and he came to the following conclusions :
The best temperature for burning calcareous Roman cements is 1,000 degrees C. Below this temperature hydr.aulicity is not fully developed, above
~Bleininger, Albert Victor, Manufacture of Hydraulic Cements: Geol. Survey of Ohio, 4th ser., Bull. 3, pp. 184, 185.

38

GEOLOGICAL SURVEY OF GEORGIA

it a D:Oill-.hydxaulic compound is evidently produced; whether On goin:g still

higher hyd,raulicity is r.esto.red has not been determined, but seems doubt-

fuL****



.

The proper burning temperature of dolomitic Roman cements is about 950

degrees C., and should be iower rather than higher.

Natural cement rock in the Lehigh district is crushed to a pea size

or smaller and burned in the rotary kiln. The length of burning is

considerably shorter than the time required to burn the rock in the upright kiln. The clinker is burned unifor~ly and as a result there is

no underburned or overburned rock, and after the clinker is crushed

and pulverized it results in a superior quality of cement.

Crushing and grinding.-The calcined "cement rock," as it comes

from the vertical kilns, consists of hard and soft material. These

materials are separated, and at some plants the hard calcined rock is

discarded while at others the soft clinker is thrown away. The calcined rock. :first. .undergoes a preliminary grinding~ The

vertical cracker known as the_ coffee mill is the type which has been

most used in the past. The :finely ground dust passes through screens

and is conveyed to the packing house while the coarser, material is

carried to the mill _for :fine grinding. The buhrstone and the rock

emery mills were the type in general use for :fine grinding until the

last decade.

The more progressive manu~acturers of natural cement today crush

the calcined rock in a disintegrater or Kent mill and then pass it to a

tube mill for the :fine gtinding. The advantages of the tube mill are:

(1) :fineness of the product, usually 90 to 95 per cent. through a 100-

mesh sieve; (2) its large capacity; (3) no screening necessary; (4)

repair of mill and wear of pebbles very small; (5) eliminating the

troublesome attention required in 'the dressing of stones which is nec-

essary in the buhrstone and rock emery mills.

Until the last decade the grinding of calcined cement rock was

seldom carried further than 95 per cent. through a 5Q!-mesh sieve. The

manufacturer now realizes that :fine grinding has the effect of increas-

ing the sand-carrying capacity of the cem~nt, making its strength test

greater in mortars and the cement more sound.

'HYDB.AULIC LIMES, N.ATUB.AL AND POBTL.AND CEM:ENTS 39
THE NATURE OF PORTLAND CEMENT
In the beginning of the modern practice of the manufacture of cements it was observed that limestones containing argillaceous matter possessed hydraulic properties when calcined. The early makers of cement attributed the hydraulic properties to the presence of the clay.
The French were the first to investigate extensively the nature of cements and while there were also many other works in Germany, England, Russia, United States, and elsewhere, it is only possible here to give a brief summary of a few of the more important investigations.
Vical made known the results of his investigations in 1818 ; however, his experiments were confined chiefly to hydraulic lime and puzzola:n.
Le Chatelier1 was the first to make a mineralogical (microscopic) examination into the nature of Portland cement. He considered tricalcium silicate (3CaO.Si02 ) the active element of cements, and found also what he considered to be tricalcium aluminate.
Richardson in 1902 illustrated the crystalline character of Portland cement by means of micro~photographs and came to the conclusion that it is a solid solution. In 1904', after carrying on the most extensive microscopic investigation yet attempted, he arrived at the conclusion that cement clinker consists of two solid solutions, i. e., tricalcium aluminate (3Ca0.A120 3 ) dissolved in tricalcium silicate (3Ca0.Si02 ) and dicalcium aluminate (2CaO.Al20 3 ) dissolved in dicalcium silicate (2CaO.Si03 ).
W. B. and S. B. Newberry3, making a study of synthetic compounds, agreed with Le Chatelier that tricalcium silicate (3CaO.Si02 ) was the active element in cements; however, they considered the alumina present as dicalcium aluminate (2CaO.A120 3 ).
Day and Shepherdi of the Geophysical Laboratory of the Carnegie Institute were the first to study the synthetic silicates both by the aid of petrologic and physico-chemical methods. They first carefully
IAnnales des Mines, 1887. 2Papers, Ass'n Amer. Portland Cement M'f'rs, June 15, 1904. sThe Constitution of Hydraulic Cement: Jour. Soc. Chem. Inds., Vol. XVI, XL ~The Lime Silica Series of Minerals: Jour. Am. Chern. Soc., Vol. XXVIII. No. 9, Sept. 1906, pp. 1089-1114.

40

_ GEOJ:.,(J(}ICAL SURVEY OF GEORGIA

studied lime (Ca.O) and silica (Si02 ) separately. They observed that calcium oxide is so refractory that with the present pyrometers it is

not possible to make a satisfactory determination of its melting point.

They succeeded by direct experiment upon pure silica in establishing

the fact that tridymite a'nd not quartz is the stable crystalline form of

silica for all- temperatures above 1,000 degrees. The further study o

silica established many important facts. Having. investigated the two

component minerals of the lime-silica series they began the study of

their relation to each other in mixtures of various proportions. After

extensive chemical and microscopic work these investigators were able

to reach a conclusion that tricalcium silicate (3CaO.Si02 ) does not
exist. Their remarks concerning the former belief that 1t was the

important constituent of Portland cement are as follows1 :

A moment's c.onsideratioiJ- shou1d suggest t,hat th81re is no. real necessity

for assuming the existen.ce of the tricalciu1ll silicate in order to explain the

nature of Portla,nd cement.. It is a systein Of .at least three components with

a great number of p'osstbilities. The real difficulty appears to have been.

that crystalized lime is. reJ,atively inert and does not reaidily giv.e the reactions

common to ordinary linie, consequently the tests which we-re thoU:ght to dem-

onstrate the absence of free lime in these preparation.s have proved very mis

leading. For example, we have found that crystals of lime a.re but very

slowly attacked by water (See page 1,094). Another argument which is freely

offered, that there ca,n be 'no free lime present ''because if free lime is added

the cement dusts _spontaneously'' is obvious fallacy. Free ume does not cause

the dusting and if it did the fa0t that the aCLdition of free lime caused dust-

ing would be no proof that none was present.

.

In the microscopic sections studied, every preparation containing

more than 65 per cent. CaO (orthosilicate composition) an excess of
I
free lime could always be positively identified. The tricalcium silicate

composition was fused and cooled in various ways and free lime was always foutid present in quantity and further exa~ination of sections

made by other workers always showed free ~ime pr~sent, so they were

forced to the conclusion that no tricalcium silicate existed.

Burchar9. says2 :
"The most important p~ueiy scientific studies of the constitution of Port, lan.d c.ement clinker have been carried on during the last few year~ by Day,

1Ibid, .note 3, pp. 1106-110'7. 2The Cement Industry in the United St~tes in 1910: Advance Chapter from Mineral Resources of the United States, 1911.

"

HYDRAULIC LIMES, NATURAL AND PORTLAND CEMENTS 41..

Wright, Shepperd, and Rankin in the Carnegie Geophysical Laboratories,. Washington, D. C.1 In the more re.cent work it .has been found that a smaU addition of alumina brings out the tricalcic silicate, but it appears to have peculiar properties and limitations. For instance, the triealcic sil1cate has been found to be unstable at its melting temperature and for some degree below, so that a melt of this compound invariably cxystalizes on cooling to orthosilicate and lime. In the presence of alumina, or even alone, if held for
a sufficient" time at temperatures in the vieinity of 1,8000 the orthosilicate and
lime combine to form a new compound with new and independent properties, homogeneous within the limits above noted. As the result of about 800 observations, it has been concluded by these investigators that tric.alcic silicate belongs to that cla.ss of compounds which form by reaction between the solid components, but which de0ompose before the melting temperature is reached; that is, they axe wholly unstable in contact with the melt. The reaction is,
+ therefore, reversible and would be expcressed as follows: 3Ca0 . 8i02 ::;:::: 2Ua0 .
Si02 Ca;O.
PORTLAND CEMENT

Portland cement is derived from an artificial mixture of calcareous and argillaceous materials consisting essentially of lime, silica, alumina,

and iron oxide, which, when brought together in certain definite proportions, finely ground, and burnt to incipient vitrification, result in a fused mass known as clinker, which when pulverized to a fine powder has the property of setting under water and attaining a high compressive and tensile strength.

RAw MATERIALS

The following raw materials are used in the manufacture of Port-

land cement :

Calcareous materials

Argillaceous materials

High-calcium limestones or mar- Clays, shales, or slates

bles

Clays

High-calcium limestone with ar- Slags

gillaceous limestone

Marls

Limestones

lDay, A. L., Shepherd, E. S., and v'iTright, F. E., The lime-silica series of min-
erals: Am. Jour. Sci., 4th ser., Vol. 22, October, 1906, pp. 265-302. Shepherd, E. S., Rankin, G. A., and Wright, F. E., The binary systems of alumina with silica, lime, and magnesia: Am. Jour. Sci., 4th ser., Vol. 28, October, 1909, pp. 293.333. Shepherd, E. S., and Ram.kin, G. A.., Preliminary report on the Ternary system Ca0Al203Si02. A study of the constitution of Portland cement clinker, with optical study by F. E. Wright: .Jour. Ind. and Eng. Chern., April, 1911, pp. 211-227.

42

GEOLOGICAL SURVEY OF GEORGLA

The essential ingredients used in the manufacture of Portland cements are all found combined with one another and with other constituents in calcareous or argillaceous materials. While the essential constituents all occur in nature in the uncombined state, with the exception of lime, they are never used commercially in the u~combined form, except in small quantities when the raw materials are deficient to some slight extent in any one of the essential elements.
The raw materials from which Portland cement may be made in . North Georgia are, chiefly: (1) High-calcium limestones or marble
and clays, shales or slates; and (2) high-calcium limestone and argillaceous limestone.
Calcium carbonate, whiGh is the source of the lime, is the predominating constituent in the calcareous materials, while silica and alumina
form the chief constituents of the clays, shales ot slates. Iron oxide
is always present in both the calcareous and argillaceous materials and greatly facilitate their fluxing in the kiln; how~ver, in the manufacture of a white Portland cement iron is not desirable and the alkalies are used to promote the iiuxing.

CA.LC:A.REOUS MA.TERIALS
The calcareous materials should satisfy the following physical and chemical conditions :
1. The lithologic character of the calcareous materials should be uniform over a unit of sufficient thickness for economic development.
2. Concretions of iron in any form ; uncombined silica in the form of chert, flint, quartz veins, or when combined in the minerals tremolite and diopside, is seriously objectionable.
3. It is always essential that the magnesia content be low, so that after the argillaceous material has been added the total quantity of magnesia does not exceed 5 per cent. The magnesia content of limestone varies from a fraction of one per cent. to the true dolomites. It is one of the most important factors to be taken into consideration in the location of the calcareous materials.
4. The argillaceous co~tent consisting of silica and alumina should

HYDRAULIC LIMES, NATURAL AND FOR1'LAND CEMENTS 43
not be in sufficient quantity to interfere with the desired silica-alumina ratio in the finished product.
5. To obtain a white Portland cement the percentage of ferric oxide in the calcareous material must not exceed 0.2 per cent.
6. The alkalies are usually contained in very small amount in the high-calcium and argillaceous limestones and need not be considered;. however, they are sometimes present in objectionable quantity in the marls.
7. The sulphur content should not exceed .5 per cent. 8. The phosphorus content seldom needs to be considered, except in the marls. It should not exceed .02 per cent. High-calcium limestones.--High-calcium limestones may be halocrystalline or crypto-crystalline in their physical character. The halocrystalline limestones contain a very high percentage of calcium carbonate and are usually low in impurities. The halo-crystalline limestones, or marbles are usually massive and often the recrystallization has been so complete that all traces of the original bedding have been obliterated. The crypto-crystalline limestones in places occur in massive beds and are usually extremely dense. They are most abundant in the Appalachian Valley region, and are an important source of_ lime for the manufacture of Portland cement. The content of calcium carbonate is usually lower than in the halo-crystalline limestones with a greater percentage of impurities, consisting chiefly of silica, alumina, and iron oxide, while they are frequently associated with beds containing much magnesi]lm carbonate. Argillaceous limestones.-The argillaceous limestones are usually dense, non-crystalline in physical character and high in clayey impurities. When the silica, alumina, and iron oxide consist of 20 to 25 per cent. and the calcium carbonate consists of about 75 per cent. of the rock, it is then known as an argillaceous limestone. The argillac~ ous limestones form the most important source of both the calcareous and argillaceous materials used in the manufacture of Portland cement in the United States. The argillaceous materials are supplied in these

44

GEOLOGICAL SURVEY OF GEORGIA

. rocks and for this reason they are often classified with the argillaceous .rocks; however, the high content of calcium carbonate places them among the limestones. It is usually necessary to. add a small percentage of very high-calcium limestone to these argillaceous limestones in order to procure a suitable mix for Portland cement, although they are also the most important source of the calcareous materials.
M arls.-The marls are extensively usecl in the manufacture of Portland cement. High..calcium marls and argillaceous marls are usually well suited for making cement and are generally characterized by a low content of magnesia. The marls are seldom consolidated and the first cost of crushing is unnecessary. As marls are not found in North Georgia they will not he further discussed.

ARGILLACEOUS MATERIALS

The argillaceous materials sh0ttld -safisf~ht1J:e 0il:lowing physical and

chemical conditions :

1; Th:e lithologic "character of the argillaceous material should be

uniform over a suffici:ent thickness 'for econ0rrlic development.

2. Concretions o_f iron in any form, un.combined silica in the forrn

' Ot[!fitil).t"'ancl~q_.gapt~;~~vi~in:~)ar~ s:~ti!ffi:S{& .idpje9ti~ri.a;'J;:R~~;'' .

tct70 3. The silica cottitent .shoU:l'd, be iirG>m 60

per~ cent. Argill~

:ceousmater:i:a:ls clefici:ent-itr: sH.icacatl<be use<:t;wtth'ftee silica 1n :the

form of pure finely ground sandstone;. however, it is always most

desirable tc\1 add the silica in combined form.

4. It is always essential that the magnesia content be low so that

.the combined mix of calcareou-s and argillaceous material does not

exceed 5 per cent.

5. In the manufacture of a white Portland cerrient the clay must

b:e' sufficiently-- .:low 'iti ierric oxide ,(ilfe203} so that the combined material contains less than 0.5 per cent.

6. The content of sulphur should not exceeO. 0:5 per cent.

The following relation of the chemical ingredients of the argilla-

ceous 'material is 'preferable :

' '

The ratio of the silica to the alumina should range between 3 to 1

and. 4 to l. The sum of silica and alumina -should not exceed 86 per

HYDE.A.ULIC LIMES, N.A.TUE.A.L AND PORTLAND CEMENTS 45
cent. The sum of the alumina and iron oxide should not be more than one-half the siliq.. The closer the sum of the alumina and iron oxide approaches one-third the silica the better.
The presence of iron oxide (Fe2 0 3 ) is desirable in the manufacture of the gray cements to facilitate the fluxing; however, it should not be in such quantity as to cause the iron oxide (Fe20 3 ) content of the finished product to exceed 4 per cent.
The argillaceous materials consist of clays, shales and slates and may all be of similar chemical composition, but differing in their . physical characteristics.
Clays.-The residual clays of North Georgia are seldom suitable for use in the manufacture of Portland cement. The residual clays in the Appalachian Valley region, which are derived from high-calcium limestones and shales, may be of sufficient thickness locally to be available.
Shales and sla~es.-The shales and slates consist of fine-grained: consolidated muds and usually contain less than 5 per cent. of calcium carbonate. Shales and slates used in the manufacture of. cements are known as normal shales and slates when they contain less than 5 per .cent. of calcium carbonate, while they are known as ~alcareous shales and slates when they contain more than this amount of calcareous materiaL
CHEMICAL INGREDIENTS
The more important and essential chemical constituents, which compose the mixture in the manufacture of Portland cement, are lime, silica, alumina, and iron, while the less important or accessory con- . stituents are magnesia, the alkalies, sulphur, water, carbon dioxide, and at times the following substances: _phosphorus pentoxide, titanic oxide, strontium oxide, ferrous oxide, and manganous oxide, all of which occur in such small quantity that they can be neglected.
The chemical analyses of a cement alone does not give us any information regarding the combinations in which the chemical elements occur in the cement. Two cements containing essentially the same chemical analysis may differ to a very considerable extent in their

4:6

GEOLOGICAL SURVEY OF GEORGIA

physical properties. Definite proportions of the essential ingredients are necessary to produce a Portland.. cement that will satisfy the standard

physical tests.

CHEMICAL INTERPRETATION

In order to obtain a conception of the nature of Portland cement it

is

necessary

to

'
be

familiar

with

the

chemical

' constitu~nts

of

which

it

is composed. The more important elements contained in cements, their symbols and atomic weights are given in the following table1 :

Symbols a.1~d Atomic Weights of Elements

Element
Hydrogen_~------ ----c---
Oxygen_ ___ ________ . __ ~ __ _ Silicen _______ . __ .. _____ . _ Aluminum __ .. ___ . ________ _ hon__________________ _ Cidcii.llli _______________ _
Magnesium..:~-- --------Carbon _______ .:. __ _____ _ Suiphur _ ____ ___ _ _ ______ _

Symbol
H 0 Si AI Fe Ca Mg
c s

Atomic Weight
1.01 16.00 28.4:0 27.10 55.90 4:0.10 24:.36 12.00 32.06

!he analyses of the raw materials and cements are always given in th~. form in which these elements. are co:J;Tiqined.

The more important compounds which constitute a Portland cement

mixture are :
. '

Calcium carbonate (CaCOs)

Magnesium ca:rbouate (Mg008)

Silica

(Si!0 2 )

Alumina.

(Al20s)

Oxide of iro.n

(F~Os)

Alkalies

(N~O, K20)

The chemical interpretation of these compounds is as follows :

The molecular weight of any of these compounds is equal to the sum of the atomic weight of the elements constituting the compound.

The percent.age of any element contained in the compound is obtained by adding the atomic weights and dividing the result into the atomic

1Jones, Harry C., Elements of Inorganic Chemistry, 1908, pp. i21-122.

HYDEAVLIC LIMES, N.A.TVE.A.L AND POETLA.ND CEMENTS 41
weight of any one element. For example, take calcium carbonate (CaC03 ), which may be considered as made up of lime (CaO) and carbon dioxide (C02 ) :
One atom of Ca has an atomic weight of_ ____________ 40.1 One atom of C has an atomic weight oL______________ 12.0 Three atoms of 0 have an atomic weight of 3 X 16 or__ 48.0 The moleeular weight of the ca~cium carbonate is equal to the sum of the atomic weights of the elements constituting the compound. The molecular weight of the lime (CaO) equals the sum of the automic weights of its elements, that is, 56.1. In order to obtainthe percentage of any one element in a compound divide the atomic weight of, that element by the sum of the elements contained in the compound. For instance: Ca has a molecular weight of 40.1 0 has a molecular weight of 16.0 } 56.1 Percentage of calcium (Ca) in lime (CaO), 40.1 -+- 56.1 = 71.4 Percentage of oxygen (0) in lime (CaO), 16.0-+- 56.1 = 28.5 If the percentage of lime ( CaO) is giy.en and the .percentage of calcium carbonate (CoC03 ) is desired divide the percentage of lime (CaO) by .56 and if the calcium carbonate (CaC03 ) is given and the lime (CaO) is desired multiply the percentage of calcium carbonate (CaC03 ) by .56.
CALCULATION OF CEMENT MIXTURES
In calculating mixtures of calcareous and argillaceous materials for the first time it is necessary to rely entirely on the chemical analyses of the untried materials. It has not yet been found possible to scientifically express the composition of Portland cement in a mathematical formula, so it is therefore impossible to arrive at a definite conclusion as to just what the ultimate analyses of the cement of any local raw materials should be except through experiment. It is possible to arrive at a close approximation to the ultimate composition of the
+ cement by the use of a formula (3CaO.Si02 2CaO.A120 3 ) pre-
sented by Prof. Newberry for the constitution of Portland cement. In Prof. Newberry's calculation the percentage of iron oxide is added to

4:8

GEOLOGICAL SUEV:BJY OF GEORGIA

the perc<;!ntage of aluminc,~., the. total being considered 'as alumina, while

he .does not take into account the magnesia. Eckel presents a formula

which differs from Newberry's only in the fact .that the magnesia and

the iron are allowed for. The various steps in th~ proportioning of a

cement mixture as given by Ecke11 are :

Opera,tion 1. Multiply the pe:rcenta.ge of silica in t'he clayey materiaJ by

2.8, the percentage Of alumina by 1.1, and the percentage of iron oxide by 0.7;

add the produts; subtract from the sum thus obtained the percentage of lime

oxide in the ela..yey ma,terral plus 1.4'times the percentage of magnesia and call

the result n.

Operation 2. Multiply the percentage of silica in. the calcareous material

by 2.8; the percentage of alumina by 1.1, a,nd thepe:rcentage of iron O:J:Cide by

0.7; add the p:roduets and subtract tihe sum from the percentage of lime oxide

plus 1.4 times the percentage of magnesia in the. calcareous material, calling
the result m.

Oeration 3. Divide n by m. T'he quotient will be the mnhber of parts

of calcareous material required for one part of clayey m:l'J,terial.

Example. Assuming that materials of the following composition are in

use the operation would be as follows:

Clay

Limestone

Siliea (S:i!02)

62.2

2.4

Alumina (AliOs)

16.1

' 2.0

Ferrie. oxide (FezOs)

4.2

0.3

Lime (GaO) _ JIII;agruesi!). (JIIIgO)

1.6

50.2

1.2

1.5'

SulphUl' trioxide (808)

1.7

0.6

Al~aJies (Na20, K 20)

0;8

0.4

Water, carbon dioxide, etc. 12.2

42.6

Operation 1, clay:

Silica

X 2.8 = 62.2 X 2.8 = 174.16

Alumina

X 1.1 = 16.1 X 1.1 = 17.71

Iron oxide X 0.7 :_ 4.2 X 0.7 = 2.94

Lime JiA:agnesia

X 1.0 = X 1.4 =

194.81 1.6 X 1.u = 1.60 1.2 X 1.4 = 1.68

3.28

194.81- 3.28.= 191.53 = n.

Operation 2, limestone:



Silica .Alumin!a Iron oxide

x. 2,.8 = 2.4 X 2.8 =
= X 1.1 =. 2.0 X 1.1
= = X 0.7 0.3 X 0.7

6.72 2.20 0.21

9:13 '1Cements, Limes and Plasters, 1907, pp. 892-893.

HYDRAULIC LIMES, NATURAL .AND PORTLAND CEMENTS 49

Lime Magnesia

= = X 1.0 50.2 X 1.0 = X 1.4 = 1.5 X 1.4

50.20 2.10

52.30 - 9.13 = 43.17 = m.

52.30

Operation 3:

- = --- = n

43.17

part of clay by weight.

4.44 parts .of limestone to he used for each

m 191.53

It must be recollected that the value given by the above formula repre-

sents t:he- highest amount of lime theoretically possible un.der the best possible

conditions of :fine grinding :and thorough burning. Even in the best run plants

these conditions cannot be attained in practice, and in .a trial run either in a

test kiln or in actual plant it is foolish to attempt to rea.ch this limit. 'The

limestone shoWlll by the formula s:hould therefore be reduced in order to get

safe results. A reduction of 10 per cent. will probably be satisfactory. In

the example given .above this would wo.rk out 'as follows:
= 4.44 parts of limest,one (to 1 of clay) allowed by formula= 0.44 10 per cent. reduction for safety.

= 4.00 pa;rts of limestone (to 1 of clay) to be actually used.

TRANSPORTATION FACILITIES AND MARKETS
The first essential specification in the location of a Portland cement plant is that it shall have adequate transportation facilities. A plant should be located if possible either on a water route and a railroad or in close proximity to two railroads. A location with respect to an adequate market is another essential factor.

CONDITIONS AFFECTING DEVELOPMENT
Determination of quality.-In the search for raw materials suitable for the manufacture of a Portland cement it is desired to secure beds of definite and uniform chemical composition over lithologic units of sufficient thickness to be economically available. Limestones and dolomites cover wide areas and are often of great thickness. Limestones containing more than 5 to 6_ per cent. of magnesia can not be successfully used in the manufacture of a Portland cement. The relative content of magnesia in the calcareous rocks can be told with considerable accuracy in the field. Dolomites and dolomitic limestones can always be detected in the field by the fact that when they are treated with dilute hydrochloric acid they effervesce with difficulty. Magne-

50

GEOLOGICAL SUB}TEY OF GEOBGIA

sian limestones containing from 5 to 15 per cent. of magnesia effervesce more slowly than the high-calcium limestones. When highcalcium limestones are treated with dilute hydrochloric acid they are entirely dissolved.
In the search for a limestone available for a cement, it is first desirable to select a section where the limestone is best exposed in the formation and to make a Gareful study of the character of each lithologic unit and ~o colle<;t samples for chemical analyses from every inch of each unit. The physical character Of the calcareous rock is usually a criterion of the chemical composition and when a thorough knowledge of the whole formation is obtained any definite bed can be recognized when exposed and its chemical composition known with sufficient accuracy to justify a careful sampling for a definite accurate knowledge of the rock at arty point.
Irt the search for argillaceous materials it is a:lso essential to be
familiar with the relation ?f lithology to chemical character. The
magnesia content in the argillaceous materials is usually low and the most important _factors to be taken into consideration are the silicaalumina tq;tio, the ,.cpntent of iron, and the physical character of the
. argillaceous material. Determination of quantity.-The determination of the quantity of raw materials is an essential factor in the location of a Portland cement plant. A plant should not be built unless there is sufficient raw material present to supply a mill with a capacity of 2,000 barrels a day for at l~ast 25 years. The term so often used "the indications are that 'the materials ate inexhaustible" is sufficient proof that the author of such a. statement knows but little of the occurrence of these materials. What is desired are the facts, and nothing but the facts should be con~idered concerning raw materials.
The horizontal length and width of the outcrop and the depth to which it can be commercially won can be easily ascertained. The number of cubic feet of stone can be obtained by multiplying these values, which, multiplied by the weight of one cubic foot of the material in

HYDRAULIC LIMES, NATURAL AND PORTLAND CEMENTS 51
pounds, divided by 2,000 (2,000 pounds to the ton) will give the available tonnage.
Relation to topography and drainage.-The locatio.n of the plant in its relation to topography and drainage has an important bearing on the cost of manufacture of the cement. If the quarries of the calcar~ous and argillaceous materials are so situated that the raw materials can reach the plant and pass through each process to the final bagging and packing by means of a gravity system, it is needless to say it can be done at considerable less cost than at the mill where the raw materials are raised from below water level to the mill, and raised and reraised through the many processes to which it is necessary to pass the raw materials. Quarries located above water level can be drained with ease and thorough drainage greatly facilitates the quarrying of the rock in wet weather.
. Ove1'burden.-The thickness and character of the overburden, if present, should be carefully ascertained. The writer has seen quarries started where in a very short time the amount of the overburden will reach a thickness, due to the dip of the rocks, that will prevent the commercial winning of the raw materials.
Location with respect to fuel supply.-A Portland cement plant must be located in the close proximity to a fuel su1_:>ply. The fuel con= sumption represents one of the largest items in the cost of manufacture. Great water-power developments may furnish power for the operation of the machinery; however, it will be necessary to use coal as a fuel in the burning of the raw materials in the rotary kiln. While the highcarbon coals, that is, anthracites and semi-bituminous coals, give higher temperatures than the bituminous coals they are not as satisfactory as the bituminous coals for use in the rotary kiln. When the high-carbon coals are pulverized and blown into the kiln combustion takes place more slowly than when pulverized bituminous coal is used.
The specifications for a coal to be used in the rotary kiln for the burning of the raw materials to incipient vitrification are as follows :
1. The volatile matter should be high, preferably between 30 and 40 per cent., so that the maximum temperature is 1_:>roduced in the

52

GEOLOGICAL SURVEY Oli' Q-EORGIA

rotary kiln about 10 feet from the lower end of the k:iln. When the

maximum temperature occurs too far ,-from the lower end of th'e kiln

it causes "ringing" and it makes .it difficult .fof the burner to watch the vitrification of the clin):<er, through a knowledge of wpich he r~gulates

th~ burning.

2. The fixed carbon should preferably range between 50 and 60

per cent.

,

3. The lower the content of sulphur in the. coal the better. When

the content of su1phur is more than 1 per cent. it is liable to cause

many. difficulties.

4:; The lower the content o.f ash the better. A high content of

ash rtot only decreases the heating power of the coal, but a considerable

P,ortion of the ash is contained in the cementmixtttre, andthus ash in

excess contaminates the finished cement.

COALS ACCESS~LE TO NORTH GEORGIA
Chattanooga. district.-The coals available .for use in the manufaGture. of Portl~u,d cem~nt in North G~orgia can be obtained from the Chattanooga district, c~ntaipip.g portions of the three states of
Q~9rgi~,, Al<:rbam~t~i~l,ta. We17~e,,S~e:
Bayes1 defines. tP,e limits .of ,the ChattaJil.ooga dis:trkt as follows :
Tbe Chattanooga district includes the territory from t'he Emo-ry River
S()11t:I:J.J>Y"at:d ;a short distance into: northern Georgi~ and 1\,labg.:rp.a. It includes tlie'Sewa:riee b:a&in, which is a portion of the Cumberla,n,d Plateau, the Wald.en ba~in, separ.ated from the Cumbetl.and Plateau .on the west 'by Sequatchie "VIal}:Ky,, ftn~,.;th~- Look,qut basin; :w:hich occupies the northern portion of the . Lookout Mountain syncline.
AnalyE;es of coa.ls .fr:om the, T.enness.ee portion of the Chattanooga d.rs.tr.1ct2 are g1 ven b.e1ow.

iHayes, c. w., 22111d Ann. Rept. u. s. Geol. survey,. Pt. III, 1902, pp. 234,.
2Shiflett, R. A., Mineral Resources of Tennessee for 1909, pp. 35-36.

HYDRAULIC LIMES, NATURAL AND PORTLAND CEMENTS 53

Chemical Analyses of Coals from Tennessee Portion of Chattanooga District

County and Operating Name of

Company

Coal

Cll 00
,..:<;:.::l::)
0
:2
E-<

:::::
0 '""d .!;~:.I...;
~0 ~

(1)
~

..~,_,

s ~~
~

p0..

..0
<:':JJ

<l)

;...;
..;,:_:,l

'"';::l

orfJ

..J:l 0..

~

'3
rJJ.

-- ~

BLEDSOE COUNTY-

IDS. per ct.\per ct. per ct. per ct. per ct.

~ Atpontley Coal Co ____ Sewanee_____ - 34 63 .571 28. 17 7.10 1.61 1.15

CUMBERLAND COUNTY-
~ Clear Creek Coal Co __ Isoline _______ 44 53.86 42.20
F-all Creek Colliers ____ Upper Sewanee 50 63.70 30.76 Renfro Coal & Coke Co Sewanee______ 42 68.27 28.32
Waldensia C'l. & C. Co Upper Sewanee 42-60 64.50 29.55

2.21 4.82 2.32 5.50

1. 73 0.72 1.03 0.45

1.47 0.40 0.06 0.54

GRUNDY COUNTY-
Flat Brarich Coal Co __ Sewanee______ Nunely Ridge Coal Co Sew:mee______ Sewanee Fuel & Iron Co Sewanee______ Ten. Consol'd Coal Co Sewanee__ . ___
HAMILTON COUNTY-
Montlake Coal Co ____ No. 10 _______
New Soddy Coal Co. (Big S) ______ . _---- No.9 ________
New Soddy Coal Co. (Soddy) ____________ No.7 ________
Sale Creek Coal Co ___ No.2 ________

34 66.80 24.57 7.43 1.20 0.66
36 61.68 29.73 7.65 1.04 ------
30 59.88 31.32 7.50 1.30 0.85
42 61.68 29.73 7.65 1.04 - ----
36 64.92 26.34 8.74; ---- -- 0.84
I
30 61.22 27.40 10.11 1'.27 0.47
27 60.44 29.18 7.16 2.10 1.12 42 60.29 31.27 7.02 1.42 0.60

MARION COUNTY-
Battle Creek C'l & C Co Battle Creek__ 24-312 59.77 34.74 New Etna Coal Co____ Kelly ________ 32,73.12 20.26 Nunley Ridge Coal Co Sewanee______ 48 61. 681 29.73 Ten. Consol'd Coal Co Sewanee______ 36 60.601 30.30

5.12 0.02 0.17
4.70 ---.--- ------
7.65 1.19 0.73
6.00 1.04 -- ----

RHEA COUNTY-
Fox Coal Co. L ______ No.2 ________ Fox Coal Co. 2 _______ No.5 ________ Dayton Coal & Iron Co Richland _____

240 60.57 34.23 3.77 1.43 0.51 30 60.24 28.97 9.45 1.34 0.82
22 59.20 31.00 12.40 ------ 0.99

ROANE COUNTY-
Roane Iron Co _______ Sewanee______

54 53.76 30.13 15.96 ------ 0.61

SEQUATCIDE COUNTY-:-
Southern Steel Co_____ Sewanee______

48j 58.85 29.50 10.55 1.10 0.86

WHITE COUNTY-
Bon Air Coal & Iron Co Ravenscroft, Mine__ Bon Air_ _ .___
I
Bon Air Coal & Iron Co Bon Air, Mine______ No.3 ________
Clifty Creek Coal Co __ Sewanee______

36 57.00 37.00 4.90 1.10 ------
54 57.50 33.00 7.50 ------ 2.00 48 ------ ------ ------ ------ ------

54

GEOLOGICAL SUlWEY OF GEORGIA.

Georgia Coals.-The commercial coal deposits of Georgia occur only in Sand and Lookout mountains in Walker, Chattooga and Dade counties.
Lookout and Sand mountains structurally consist of shallow synclines separated by the Lookout Valley anticline. The base of these mountains consists of the Bangor limestones immediately above which occurs .the Lookout sandstones and shales. The coals worked in the vicinity of Coal City in Sand Mountain occur in what are known as the lower coal measures, that is, in the Lookout sandstones and shales. The Walden formation lies stratigraphically immediately above the Lcmkout formation and carries the Sewanee coal. Only a comparatively small remnant of this formation remains on Lookout Mountain and forms what is locally known as Round. Mountain.
Chemical A'nalyses of the: More Impv:rtiJ/n't Coals of Georgia.

Name of Location of

Coal

M:fue

'

ttl

Q.)
:':":s'
:$
0 ~

>=!
0
"g~
~ <:.J

s .~.........., $..<..:.a,
~
~

,.t:l
~

~

E! ..Cl

,,..t.:el .
:::! 00.

Q.
~

Analyst or authority

--

Suwanee1 Durham, Walker

Gustave Bedell,

County-- ____ ----- 79.100 16 ..030 4;810 (). 3600.. 007 Cha.ttanooga,

Sewanee2 Durham, Walker

A. s. Hewitt,

----- County______ 0.615 75.956 21.011 1.9400.470

New York.

Tatuma __ ~ Rock Or eek

N. P. Pratt

Gulch, Walker

Laboratory,

~County_~ ____ 1.02075.980 20.850 1.440 0.760 0.007 Atlanta.

Rising Rising F a w n,

A. s. :H~witt,

Fawn4 __ Dade County_

75.756 19.046 4.840 0.786 0.002 New York.

R!'.l.ccoon5 Cole City, Dade

N. P. Pratt

County ______ 1.150 60.120 24.850 13.880 1.510 -. -.... Laboratory,

Atlanta.

lSpencer, :r. w., Geology of the Paleozoic Group of Georgia and Resources
Geol. Survey of Ga., 1893, p. 258.
2Ibid, p. 258.
sMcCallie, S w., Coal Deposits of Georgia: Geol. Survey of Ga. Bull. 12, 1904,
p. 42.
'Average of three analyses, Spencer, J. W., Geology of the Paleozoic Group of Georgia and Resources: Geol. Survey of Ga., 1893, p. 259.
5McCallie, S. w., Coal Deposits of Georgia: Bull. Geol. Survey of Georgia No.
12, 1904, p. 90.

HYDE.A.ULIC LIMES, NA.TUEA.~ .AND POETLA.ND CEMiENTS 55
Correlation of the coal beds of Georgia with one another and with the coal beds occuring in similar formations in Tennessee and Ala~ bama have been attempted on lithologic grounds by many workers; however, they have hardly been more than conjectures. Prof. S. W. McCallie, in speaking of the correlation of the Georgia coals aptly remarks1 :
The only solution to the quesUon of correlating the coal seams of the upper coal measures of Lookout Mountain with the co.al seams elsewhere, seems to lie in the paleontological evidence furnished by the associated shales. Many of these shales teem with p}ant remains, which, if properly studied, would, no doubt, furnish valuable aid in conelating the various coal seams of Sand and Lookout mountains. Until such evidence is obtained no correlating, of any scientific value, is likely to be worked out.
Analyses of Coals of Georgia by Dr. William Henry Emerson2

--
I II III
IV
v

Carbon 1
85.75 86.97 79.41 85.07 84.32

Hydrogen Water

2

3

4.63

.88

4.44

1.06

4.60

.93

4.48

.77

4.72

1.21

Sulphur 4
.79 .62 .88 .88 .78

Nitrogen 5
1.44 1.25 1.39 1.50 1.66

Ash 6
3.17 2.00 9.05 3.42 4.20

--
I II III
IV
v

Calculated heating value 7
8.366 8.351 7.821 8.234 8.292

Colorimeter
8
8.415 8.409 7.763 8.290 8.211

Difference
9

Difference Heating val- Fixed carbon,

I per cent. ue per gram and moistof combust'n ure, free

10

11

12

-49 -.6

8.770

79.1

-58 +58

+- . 7 .7

8.675 8.624

78.4 75.3

+ + -56 81

-.7 1.0

8.653 8.680

78.0 78.1

I. Lump coal, Durham Mine, Walker County. II. S. T. Carson's property, Walker County. Vein 120 feet below Durham. III. S. T. Carson's property, W.alker County. Vein 180 feet below Durham. IV. Washed coal, Durham Mine. V. Unwashed coal, Lookout Coal & C.oke Co., w,alker Coun.rty. T:he last two columns show that all these coals belong to the same class, t'he differences not being greater than those that might arise in coal from the

1coal Deposits of Georgia: Georgia Geological Survey Bull. No. 12, 1904, pp.
112-118. :eontained in report by S. W. McCallie, Geological Survey of Georgia, Bull.
No. 12, 1904, pp. 116-117.

56 '

GEOLOGICAL SURVEY OF GEOR-GI.A

sam.e mine :flrom difference of sample combined with experimental errors. They
fall,in th~ lower part of the semi~bituminous class, wh0se heati:ng value, ac-
to coraing Prof. Wm. Kent, ranges from 8,666 to 8,888 caloTes, and whose
fixed carhon r8!tJ..ges from 75 to 85 per cent.~

WINNING 'I'HE RAw MATERIALS

The winning of the raw materials is om~ of the most important

factors to be taken into consideration in the cost of cement manu-

facture and one which has probably been most neglected. In North
Georgia <the-.raw materials can only be econGniicallyJ wo.n by open quar-
ryin."g. . It is most desirab1e to loc~te the quar~ies on the .hillside in

order to secure a long working face, to fe~;cilitate the drainage of the

quarry so that wet weather will not interfere with quarrying and to

make it possible to convey the raw materials to the mill by means of

gravity. It is seldom possible to secure both the limestone and the
shale in such ari Jd'eal posit~on; ho.we:&:er, ii the two materials are not

in immediate proximity it is most desirabJ.e to locate the m}ll, provided

all other conditions ate satisfactory, at the source of the liemstone, as

about three or feur parts of limestone are use-cL to one part of shale.

The quarrying consists first o.f stripping. the overburden, if such

ih occur,s, w. h.i. ch,

North

Georgia,

'l:lsuali~

edn~{~ts '

.:o:!..,It~$id~a(or

trans-

ported days mor_e or less heterogeneous in physkal~nq\~he1.1:iical char-

acter, 'it{ 'Order to prevent the tontarhination di;tHi~ rria%~fial'~With the

on quarry stone. The method of working the quarry depends the loc~l

topographic and geologic conditions. Limestone quarries are usually

best worked in ot;te or more henches. After the drilling and blasting

of the rock froth place, the m6re massive rock is sledged or reblasted

and then loaded ~~ther by hand or steam shovel into carts or ,small cars

and taken to the stone house. V{hen a quarry is worked to a consid~rR;ble depth -be-lGw water le:vel or ,some disf~n~e from the mill the

raw material may be lifted from the quarry and conve:y~d to the mill

by means qf an aerial tram. In the quarryl.ng of shale where it is.

physically homogeneous over a sufficient thic}mesS; steam shovels are

far mbr~ 'satisfactory than in the winning of limestone.

1Efii'erson, William H., in Coal Deposits of Georgia: Geol. Survey of Georgia, Bull. No. 12, 1904, pp. 116-117.

HYDB.AVLIC LIMES, N.ATDB.AL AND POBTL.AND CEMENTS 57
PROCESS OF MANUFACTURE
Limestone.-The limestone first undergoes a preliminary crushing, which results in a stone of about two inches in diameter. The stone necessary for the day's run passes directly to the rotary driers, while the excess of crushed stone should pass to storage bins having a ten days to two weeks capacity in order to provide for the night's run and to supply the mill in case of any break-down in the stone house. The driers both for limestone and shale, if located close to the kilns, can utilize the waste heat from the kilns and save the additional expense of fuel for drying the raw materials. When the limestone leaves the driers it should be conveyed to storage bins with at least a twenty-four hour capacity, so that the mill will be supplied with stone in case of any delay in the drying.. The limestone then passes to the mills for preliminary grinding, from which it is conveyed to a storage bin.
Shale.-The shales first undergo a preliminary crushing and are conveyed, like the limestone, to storage and driers and thence to the mills for preliminary grinding, from which it is conveyed to a storage bin.
lvfi.::ct~we of limestone and shale.-The ground limestone and shale at this point in the process of manufacture are drawn from the storage bins in the proper proportions as determined by the chemist and thoroughly mixed. The mix can be made by alternate drawing of portions of the _calcareous and argillaceous materials or by the use of automatic mixing machines. The mix is then conveyed to the pulverizing machines, from which it passes to the kilns where it is burned to incipient vitrification ancl passes out of the slightly inclined rotary kilns as clinker and is conveyed either to cylindrical coolers or direct to the clinker pile, where it is exposed to the atmosphere and allowed to season and soften. The cool and seasoned clinker is conveyed to the finishing house. The clinker now undergoes a preliminary grinding, the gypsum to retard the set is added and then the ground clinker must be pulverized. After the process of the fine grinding is complete the cement passes to the stock house where it is stored and seasoned and then packed in bags ready for shipment.

58

GEOLOGICAL SUEVEY OlJl GEORGIA

. HINTS EN CONSTRUCTIONOF Pl:.AN:WS

.

1. Each grinding unit should nave its storage bin with at least a

twenty'-f6ut .hour capidty.

2. Each kiln s'hotild be providecl with a storage bin with at least ,

a twenty-four capa61ty:

3. The limestones of North Georgia available for the manufacture
are of cement nard. co\iipa2t seti1i.:.crystallh1e to. crystalline in physical

. character and require a h~avy machine for their grinding and pulver-

.

.

izirig.

4. Sli:f?cient grinding machinery to provicie for an ample capacity

should be installed, so that the mills can turn out considerable more

material than is ordinarily required of thEmi.

5. In order to acquire the grea'test efficiehcy all machines which
operate tbgtither in ' oclJt.rfirtg ouit kn.~;. o-Re prb'bes;s' 'shO;uM have their

power derived from the same sburce. 6. Th~ p6Wer 'sh.bhld be s6 s'ilbdivid~ed that any machine may be
cut out withHtit sfd,~j)itig tHb oti~dt'ion 6foH:lei rriathiries.

sl:ii\G- G;gJ?u~Z'dtWN d~NT.sL'

-" Th~ -~~w materials f-rom which the slag or Puziolan cements is made 'fri this' country con~ist o! 'i)iast-furnace slag ~rid high-calciu~

limestone. The analyses of the siag must be constantly made so that

be up l, -' : . ,

-

,

~ i .

I

. '' . < ,,, , ,. ~ , i. '

'

th~ prop~r cemerit iniittire "can . made either be!ore or after the

prelHninary gfinding. The process ,ater the mixture of the

.Lf . _ ~!,.::-(: -t~1 -:.\.-~;-::1~-.,.:~ it.;-/.:~- ~!)'tr:

~.:-~:.J::-,:

-~---

materials is prec~s.ely; like tha.t: of _Portland cement manufacture.

'