Paleontology and biostratigraphy of the upper Bangor limestone (Mississippian) around Lookout Mountain, Georgia-Tennessee [May 1980]

PALEONTOLOGY and BIOSTRATIGRAPHY of the
UPPER BANGOR LIMESTONE (MISSISSIPPIAN) AROUND LOOKOUT MOUNTAIN, GEORGIA - TENNESSEE
by
Johnny Ariton Waters
OPEN-FILE REPORT S(r--9
In partial fulfillment of Department of Natural Resources contract no. 79551.
Georgia Department of Natural Resources Environmental Protection Division Georgia Geologic Survey
May 1980

. .....
PALEONTOLOGY and BIOSTRATIGRAPHY of the
UPPER BANGOR LIMESTONE (MlSSISSIPPIAN) AROUND LOOKOUT MOUNTAIN, GEORGIA-TENNESSEE by Johnny Arlton Waters
Department of Geology West Georgia College
Cru7ollton,Georgia,30118
OPEN-FILE REPORT SQ--9
In partial fulfillment of Department of Natural Reaourcea contract no. 79551 .
Georgia Department of Natural Resources
Environmental Protection Division Georgia Geologic Survey
May 1980

Table of Contents

Introduction . . . . . . . . . .

l

Regional Setting

2

Study Area . . . . . . .

4

The Fauna

. . . . . . . . . . . . . 14

Biostratigraphy

30

Discussion . . . . . . . . . . . . . . . . . . 32
. References Cited . . . . . . . . . . . .. . . 35

Appendix A . . . . . . . . . . . . . . . . 38

i

Illustrations Figure 1. Locality Map . . . . . . . . . . . . 6 Figure 2. Measured section at Georgia 143 .. 8 Figure 3. Rising Fawn, Georgia Section . . . . . . 13 Figure 4. Cross-Section showing Depth Relations .. 15 Figure 5. Distribution of Faunas . . . . . . . . . 17 Figure 6. Faunal Niches . . . . . . . . . . . . 21 Figure 7. Brachiopod Niches . . . . . . . . . . 23

II' ,,
I
Tables

Table 1. Fauna at Rising Fawn . . . . . . . . . 19

Table 2. Inferred minimum depth relations of

. . . . . . . . Bangor Brachiopods . .

25

ii

Introduction With the widespread acceptance of the plate tectonic
model, geologists have become increasingly interested in paleogeographic reconstructions through time (e.g., Scotese, et al., 1979; Ziegler, et al. _, 1979) and implications on patterns of paleobiogeography. These large scale studies on paleobiogeography depend on numerous faunal studies covering the entire paleogeographic range under consideration as well as accurate correlations to define time planes.
The purpose of this project is to provide additional data on the paleontology and biostratigraphy of the upper part of the Bangor Limestone around Lookout Mountain in northwestern Georgia and southeastern Tennessee. The paucity of data from this area has already been noted by Sando (1977) ~n his studies of Mississippian coral biogeography. Thomas and Cramer ( 19 79, Fig. 8F) have indicated that the deposits of the Bangor Limestone around Lookout Mountain represent the southeastern edge of a Mississippian carbonate platform in facies transition with prodelta muds of the Pennington Formation. Faunas from these limestones. give us a record of the distribution of organisms living at this edge of the carbonate platform.
1

Acknowledgements The Georgia Geological Survey provided salary support and
maps for the field work on this project under contract 79551. Additional support for laboratory preparation of samples, travel, and literature acquisition was provided by a faculty research grant from West Georgia College. The financial support of this project is gratefully acknowledged.
Regional Setting McLemore (1971) and Thomas and Cramer (1979) have
summarized the general stratigraphy of the Mississippian in Georgia and the reader is referred to these works for summaries of previous studies. The Bangor Limestone is genetically related to a persistent. carbonate platform that ext~nded through parts of Georgia, Alabama~ and Tennessee for most of the Mississippian. The platform has been named the East Warrior platform by Thomas (1972) for deposits in Alabama. Outcrops of the Bangor Limestone in northwestern Georgia represent the easternmost exposures of these platform carbonates and the pre-dominance of high-energy carbonate textures suggests proximity to the original depositional edge of the platform.
2

In Alabama, platform carbonates of the Bangor underlying Monteagle Limestone are separated by the Hartselle Sandstone, a barrier island-barrier bar sequence that pinches out to the northeast and southwest of north central Alabama (Thomas, 1972). In Geo~gia the Bangor and Monte~gle are separated by thin shales and sandstones termed the Hartselle Formation that may or may not be genetically or stratigraphically related to the Hartselle Sandstone in Alabama (Thomas and Cramer, 1979). Correlation of these units is equivocal at this time.
The Bangor is overlain by the Pennington Formation, a wedge of delta-front clastics and dolostones that prograded onto the carbonate platform from the northeast (Thomas, 1972). The Bangor-Pennington transition represents a continuous facies change from generally high-energy subtidal carbonates to intertidal and possibly supratidal dolostones to delta-front clastics. The base of the Pennington is usually picked at the first occurrence of maroon and green shales. Regionally this contact is probably time transgressive.
. 3

Study Area
Faunas from five localities in the upper Bangor Limestone around Lookout Mountain were studied for this report (Figure 1; Appendix A). Detailed sections were measured along Georgia Highway 143 on the east side of Lookout Mountain (Figure 2) and at Rising Fawn, Georgia (Figure 3). Lithologic samples were collected from each recognized unit and thin sections and acetate peels were prepared to characterize carbonate textures. Although I used thin sections and peels to classify and interpret carbonate textures, identify fossil debris and note major diagenetic features, no attempt was made to determine the paragenesis of cements or to completely elucidate diagenetic features. All rec~gnizable fossil debris was identified on the outcrop and selected specimens were collected for further analysis. Most of the carbonates were either high energy calcarenites or dolostones and identifiable fossil debris was scarce. Shaley intervals were bulk-sampled, boiled in Quaternary "O" (an industrial agent marketed by Ciba-Geigy) to disperse clays and sieved. The three other sections represent localities where previous workers had studied carbonate textures in detail but not the paleontol~gy (Paris Hollow, Raccoon Mountain) or localities where limited exposures and time prevented detailed study (U.S. 11 south of Rising Fawn).
The Bangor Limestone on the east side of Lookout Mountain was deposited on a shallow marine shelf in
4

5 shallow water. The following depositional facies were recognized (figure 3; parts 1 and 2): (1) subtidal echinoderm grainstones, (2) high energy oolite shoals, (3) lower energy lagoonal packstones and wackestones, (4) dolomitized massive and laminated micrites and sparsely fossiliferous biomicrites from a tidal flat environment. The depositional pattern is cyclic and individual units are usually thin suggesting that the facies belts were narrow and constantly shifting. McLemore (1971) has previously concluded that the Bangor was deposited in a Bahama platform type of environment. The close proximity of facies belts also suggests affinities with a Persian Gulf type environment of deposition (Chowns, 1979, personal communication). The overall pattern for the Upper Bangor is a transition from subtidal grainstones to tidal flat dolostones and is consistent with studies by McLemore at Paris Hollow (in Chowns, 1972) and by Bergenback (1978) at Raccoon Mountain. Recrystallization, dolomitization, solution packing, and stylolitization are common diagenetic features of the limestones. The section along Georgia 143 has been faulted and a doubled solution is present. Sullivan (1942) recognized this and his conclusion is substantiated by biostratigraphic data reported herein.
5

Figure 1.

Locality map of sections studied in this report. Section 1 - exposures along Georgia Highway 143 on east side of Lookout Mountain. Section 2 - exposures along I-59 at Paris Hollow (Stop four of Chowns, 1972). Section 3 -exposures at intersection of I-59 and U.S. 11 north of Rising Fawn. Section 4 - section on Tennessee Highway 134 on Raccoon Mountain (Stop one of Bergenback, 1978). Section 5 - exposures along U.S. 11 south of Rising Fawn. See Appendix A for complete locality descriptions.

6

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Figure 2.

Measured section along Georgia Highway 143 on the east side of Lookout Mountain. Section starts at highest Limestone exposures and continues approximately one mile down the highway. Covered intervals are present. The section has been repeated by thrust faulting.

8

3ED NO I

SAMPLE NO.

'-----13
w-----..:....-...a...-...-y---&----..1,

ARCHIMEDESi PENTREMITES ROBUSTUS ECHI N0 I pACKSI ONE

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ARCH If.tEDESi ANTHRACOSP I RI FER INCREBESCENS
PENTREMITES SP,j PIEROTOCRINUS CE RUGOSUS

BRY.-ECHINO. PACKSTONE
9

?CANINOSTROTION ~.

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BUFF LAMINATED DOLO, MICRITE

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9

BED NO.
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16
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13 12 11 10
9 8
7

SAMPLE NO

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19(1) 18(1)
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MASSIVE DOLOLUTITE BLUE-GRAY WACKESTONE MASSIVE DOLOLUTITE

16(1) DOLO. MICRITE- BRY, WACKESTONE
15(2)
GRAY BRY, PACKSTONE

DK. GRAY ECHINO, PACKSTONE WACKESTONE
SILTST. &FINE GRAINED SS,
SHALE PTEROROCRINUS TRIDECIBRACHIATUS MED. GRAY OOLITIC ECHINO. GRAINSTONE
MED, GRAY BRY. GRAINSTONE DOLO. WACKESTONE
10

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00LITIC ECHINO, GRAINSTONE

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DOLO. LAMINATED MICITE

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BOUNDSTONE

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27

27(9) BRY.-ECHINO. PACKSTONE

12

FIGURE 3. SECTION OF BANGOR LIMESTONE AT THE INTERSECTION OF U.S. 11 AND INTERSTATE ~9 ABOUT THREE MILES
NORTH OF RISING FAWN 1 DADE CO. GEORGIA

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AND RED CHERT RESIDUUM {FORT PAYNE HAS OVERTHRUST

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DK. GRAY WHOLE FOSSIL WACKESTONE AND HIGHLY WEATHERED TERRA B.Q.M LS. RESIDUUM. ABUNDANT FAUNA. LT. GRAY OOLITIC LS. MED. GRAY ECHINODERM GRAINSTONE-PACKSTONE

COVERED
6'

13

The fauna The five studied localities ln the Bangor have yielded
an abundant and diverse fauna. The largest fauna was collected from deeply weathered Limestone residuum two meters below the Bangor - Pennington contact at Rising Fawn. Forty-two macroinvertebrate taxa and one vertebrate are currently recognized. The fauna includes fifteen brachiopod taxa, five molluscs, sixteen echinoderms, five bryozoans and three corals (Table 1). Specimens from the residuum are generally silicified and preservation is poor, although specimens collected from weathered limestone blocks are not silicified and preservation is good. Bryozoan and echinoderm diversity has probably been lowered by poor preservation. Juveniles of several brachiopod species as well as Pehtremites were recovered from washed residues indicati~g minimal transportation and size-sorti~g of the fauna. Samples were not processed for a microfauna.
The Bangor at Rising Fawn consists of locally oolitic skeletal grainstones, packstones and wackestones. The Bangor is interpreted to represent high energy carbonate shoals (grainstones, oolites) and slightly deeper water protected 1!3-goons (wackestones) leeward of the shoals (Figure 4). Faunas lived primarily in the protected lagoons with stable substrates (Figure 5). A few forms such as Agassizocrinus were adapted for living in the
14

F~gure 4.

Cross-section showing depth relations of inferred depositional environments from the Bangor Limestone in northwest Georgia and southern Tennessee.

15

lCARBONATE

ECHINODERM

BAR

GRAINrNES

HIGH TIDE
LOW TIDE
......
0'1

LAGOON
1

figure 4

TIDALrLAT

Figure 5.

Inferred faunal distribution in depositional framework of Bangor Limestone. Most of the fauna lived leeward of the high energy oolite bars in the protected slightly deeper water lagoon. Agassizocrinus and perhaps some bellerophantid gastropods were adapted for living on the oolite shoals. Fasciculate corals assigned to Caninostrotion probably lived in tidal channels in the tidal flat envirorunent.

17

"* AGASSIZOCRINUS

~ BRACHIOPODS

~ STEMt-1ED CRINOIDS

~ BLASTOIDS

?' BRYOZOANS
~ SOLITARY CORAL ~ COLONIAL CORALS
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~?-o'"-c

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Figure 5

Table 1. FAUNA AT RISING FAWN, GEORGIA

BRACHI'OPODS
Diaphragrrius Punctospirifer Girtyella brevilobata Girtyella indianerisis Torynifer Cleiothyridina Etunetria ?Buxtonia; ?Flexaria Composita subquadrata Coeliditun Reticulariina ? S c h u c h e r t e'l l a Arithracospirifer Teidyi Echinoconchus

ECHINODERMS
Pterotocrinus edestus P. tridecibrachiatus P. pegasus Agassizocrinus Diclfocrinus Zeacrinites Phanocrinus Acrocrinus Ophiuroid plates Echinoid plates Pentremites laminatus P. clavatus P. cheerokeeus P. .gut.s chicki ?Linocri:nus Camptocrinus

BRYOZOANS
Glyptop.o'ra Prisrn:opora Archimedes Polyp ora ramose Bry

MOLLUSCS
Platyceras (Orthonychea) Straparollus (Amphiscapha) Bellerophonoid (Euphemites~ intermediate-spired steinkern ?Wilkingia ?Aviculopinna

CORAL
Caninia ~ Zaphrentoides (Am.plexizaphrentis) spinulosa Caninostrotion ? ~
ARTHROPODA
Ka.'skia
VERTEBRATE (teeth and dermal elements)

19

unstable substrates of the oolite shoals (Ettensohn, 1975). Ettensohn and Chestnut (1979) have proposed a similar model for depositional environments and faunal distribution for the Ba~gor-Pennington interval in southcentral Kentucky.
The fauna appears to have affinities with Illinois Basin Faunas although taxa endemic to the ArkansasOklahoma area (e.g. , Pentreinites Taininatus) were recovered. Generic diversity at Rising Fawn is consistent with diversity from the Glen Dean Limestone (Horowitz, 1955) and the Golconda Formation (Rodrequiz, 1960) from the Illinois Basin, the Pitkin Limestone (Easton, 1943) from Arkansas and the Lower Bangor Limestone {Waters, 1978) from northwestern Alabama. As previously stated, lower bryozoan and echinoderm diversity at Rising Fawn is, in part, preservational.
The fauna is a typical Upper Paleozoic offshore brachiopod-bryozoan-echinoderm suspension-feeding community. Figures 6 and 7 show faunal partitioning into niches. Suspension-feeders were stratified in the water column. Brachiopods and bryozoans were low-level suspension feeders. Cainptocrinus, Dichocrinus and Pentremites were situated above brachiopods and bryozoans; other crinoids with larger stems were still higher in the water. All faunal elements were confined to the low and middle levels of Lane (1973); no high level echinoderms were found at Rising Fawn.
20

Figure 6.

Chart showing niche-partitioning in the Bangor fauna. The fauna was a typical Upper Paleozoic attached suspension feeding community. Attached suspension feeders partioned resources by vertical stratification.

21

EPIFAUNA

INFAUNA

FREE

ATTACHED

IMMOBILE

MOBILE

-

Immobile

Mobile

Low

Intermediate

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u 0
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.

Kaskia

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rl

Cll

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'

Ophiuroid (1) Cam12tocrinus Crinoids (7) ?Av.iculoEinna ?Wilkingia

'

Agassizocrinus

Dichoctirtus

l:l 0

Pentrelilites (4

rl

Cll
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Q)

bryozoans (5) brachiopod~ 10)

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Echinoid (1)

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orl > ..NC...11'M.,.o..
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Gastropods (3)

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Corals (3) Vertebrate (1)

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Figure 6 22

Figure 7.

Brachiopod Niches (Modified from Alexander, 1977)

NICHE
Anchored exclusively by spines
Unattached; commissure vertical; umbonal weighting
Unattached; commissure vertical; interarea stabilization
Functional Pedicle tethered
Functional Pedicle interarea stabilization
Cemented (at least as juveniles)

TAXA OCCURRING
Diaphra~mus
?BuxtonJ.a Echinoconchia
Coelidium explanatum
Anthracospirifer leidyi Reticulariina spinosa Punctospirifer transversa
Composita ~ Cleiothridina sublamelosa GJ.rtyella brevJ.lobata G. indianensJ.s EUmetria ~
Torynifer ~
?Schuchertella ~

23

Alexander (1977) has summarized attachment modes for articulate brachiopods. Within his classification the product ids (Diaphragmus, "?Buxtonia, Echinoconchus) were free living as adults and anchored exclusively with the corrunissure vertical and was stabilize.d by umbonal weighting. Eurn."ett'ia, Composita, Cleiothyridiha sublamelosa, Girty ella breVil.obata and G. i 'ndi'anensis were tethered by a functional pedicle. Torynifer was also attached by a functional pedicle but utilized its interarea for additional stabilization. Schuchertella (?) was presumably cemented as juveniles, but as adults may have been free living with the commissure horizontal. Anthracospirifer leidyi, Reticulariina spinosa, and Punctospirifer transversa were unattached with the commissure vertical and were stablized by the interarea.
Stevens (1971) noted differing geographic distributions of brachiopod genera in the Pennsylvanian of Colorado and hypothesized a water depth model to explain these distributions. Waters (1978) modified Stevens' model for brachiopods in the lower Bangor of northwestern Alabama, and using independent lines of evidence substantiated the water depth model (Table 2). The relative abundance of Coelidium explanatum and pauc;i.ty of Anthracospirifer leidyi and Schuchertella (?) suggests that the Bangor at Rising Fawn was deposited 1n minimum water depths of 10-15 meters. These water depths are consistent with the overall depositional framework.
24

Table 2. Inferred minimum depth limits of Bangor brachiopod. genera. Steven's absolute depth ranges are indicated for reference purposes only. Life histories of nearshore genera were more opportunistic than deeper-water genera.
25

Table 2

MORE OPPORTUNISTIC NEARSHORE

MORE EQUILIBRIUM OFFSHORE

Strand line

Bm

12-15m

Anthracospirifer Leidyi

Composita

Schuchertella (?)
1:\J

"'

Reticulariina

?

Diaphragmus

?

Cleithyridina

Eumetria Punctospirifer

? ? __________________? (Rare in this study)

Echinoconchus

Coelidium

Girt~lla

?

? (Rare)

Torynifer

Sixteen different echinoderms based on fragmentary remains are recognized from Rising Fawn. Echinoids and ophiuroids were identified entirely from disarticulated plates and could not be identified to genus. Nine crinoid genera and species were recognized from (..!alyces and separated cup plates. Camptocrinus is recognized exclusively from diagnostic stem fragments. Three species of Pterocrinus were identified from wing plates (highly modified tegmen spines) although calyces were undifferentiated. The taxonomy of Pterocr'inus is partially based on either wing plates or calyx morphology and in many cases the calyx is unknown for species based on wing plates. Agassizocrinus is identified solely from its fused infrabasal circlet which lacks a cicatrix for stem attachment. Flexible crinoids were either absent or rare as none were recovered in this study. Four species of the blastoid Pentre:mites were recognized. P. cherokeeus was the most abundant species and is characterized by prominent flaring deltoids. ~ gutschicki is a broad godoniform species currently recognized as restricted to the Kinkaid interval in the eastern United States. P. clavatus is a rather narrow pyriform species. P. laminatus is a narrow godoniform species from the Pitkin Limestone of Arkansas. Drahovzal (1967) identified this species from the basal Pennington in western Alabama and its presence in equivalent strata in Georgia is herein reported. Echinoderms are important

Chesterian index fossils and biostratigraphic significance of the Bangor echinoderms will be discussed in a separate section.
Three genera of rugose corals are recognized from the study area. zaphrentoides (Amplexizaphrente s ) spinuldsa is a small trochdid solitary coral that is very abundant at Rising Fawn. The remaining two coral genera are members of the Family Cyathopsidae although generic placement is tentative. I have assigned large trochoid solitary corals found ln the study area to Caninia based in part on discussions in Sando (1965) and Sando (personal communication, 1978). Fasciculate rugosans have been assigned to Easton's (1943) genus Canin'ostrotion. Easton established Caninostrotion primari~y to include compound Canina - like specimens. Sando (personal communication, 1978) questions the validity of caninostrotion and suggests that it probably
has affinities to campophyllum gasperense Butts =
Lithdrumus vergi Greene. I have collected some specimens that do resemble. C. gasperense, but others that are obviously different. Pending restudy of these genera and a reassessment of their affinities, the specimens are assigned to Caninostrotion. Caninia and Caninostrotion occur in interbedded calcarenites and dolomite mudstones. Compound corals were usually preserved upright in mudstones in presumed life orientation. Colonies approaching one M3 volume were noted along Georgia Highway 143. Caninia
28

specimens usually were preserved in micrite "coral beds" which weathered to a brownish pinky dolomitic residuum. Most specimens were silicified and interval structures were poorly preserved. Selective silicification and dolomitization of the coral beds probably resulted from increased diagenesis of the porous layers. Caninia and Caninostrotion probably lived in tidal channels (Figure 5) in very shallow water, and represent the primary faunal elements collected from localities 2 and 5.
29

Biostratigraphy
Mississippian biostratigraphy in Georgia has been recently summarized by Thomas (1979). Historically the Bangor Limestone has been correlated with the Glen Dean Limestone of the Illinois Basin (Butts, 1926; Butts, and Gildersleeve, 1948; Horowitz and Strimple, 1974) and the Pennington Formation was inferred to represent Upper Chesterian time. Biostratigraphically important elements identified from this study include the following:
Pterotocrinus edestus P. tridecibrachiatus P. pegasus Pentremites laminatus Pentremites gutschicki P. cherokeeus ?Caninostrotion variabilis Caninia ~ Species of Pterotocrinus have been extensively used as index fossils in the Illinois Basin and the three species herein identified are restricted to the Kinkaid Limestone (Gutschick, 1965; Horowitz and Strimple, 1975). Using plate morphologies of Kinkaid Pterotocrinus species are distinctive and easily recognized. In addition Kinkaid calyces are characterized by 30 biserial arms rather than 20 arms in pre-Kinkaid
30

species. I have collected numerous wing plates and several calyces that are consistent with morphologies described by Gutschick for Kinkaid Pterotocrinus species for the Illinois Basin. Drahovzal, 1967 has reported these species of Pterotocrinus from the Upper BangorPennington transition in Alabama.
Pentremites laminatus was originally described by Easton (1943) from the Pitkin Limestone in Arkansas and is not known from the Illinois Basin. Drahovzal, 1967, reported specimens of P. laminatus from western Alabama, and I have collected and identified several specimens from Rising Fawn. Brenkle, 1977, correlates the Pitkin with the Menard to Kinkaid interval from the Illinois Basin. ~ gutschicki is a distinctive broad godoniform species from the Illinois Basin. Currently its range is restricted to the Kinkaid Formation (Horowitz and Strimple, 1974). P. cherokeeus and closely allied spicate godoniform species range from Glen Dean to Kinkaid in age.
Caninostrotion variabilis is known from the Kinkaid Formation of Illinois and the Pitkin Limestone of Arkansas. Caninia is a coral genus that ranges from Upper Mississippian into the Pennsylvanian. Caninia characterizes Sando's coral zone K (Upper Chesterian) in the western United States.
In summary, the available macrofossil zonations suggest that the Upper Bangor Limestone in northwestern Georgia and southern Tennessee is at least Upper Chesterian (post Glen Dean) in age and is probably age equivalent with the Kinkaid Formation of the Illinois Basin.
31

Discussion
The assignment of a Kinkaid age to the Upper Bangor has implications in several lines of study. Drahovzal (1967) concluded that the Upper Bangor in northwestern Alabama was also Kinkaid equivalent. Drahovzal's data, this study, and unpublished data I have gathered from northeastern Alabama all form a consistent age picture for the Bangor. The depositional environment of the Upper Bangor also forms a consistent picture in these studies. The Bangor - Pennington transition is a continuous facies change from subtidal echiniderm grainstones, oolite shoals, lagoonal packstones and wackestones, and dolomitic tidal flat sediments of the Bangor to prodelta muds of the Pennington. Ettensohn and Chestnut (1979) have reported a similar sequence for the Bangor - Pennington transition in southern Kentucky. They have also reported a very abundant echinoderm fauna living in protected lagoons behind oolite shoals. The relatively reduced echinoderm fauna in northwest Georgia probably results from the relative paucity of preserved lagoonal sediments.
Based on the occurrences of Pterotocrinus acutus, P. bifurcatus and related forms, Ettensohn and Chestnut concluded that the Bangor - Pennington transition in Kentucky occurred in Glen Dean time. This sugge~ts
32

that the facies transition is time-transgressive

and is younger in the southern Appalachians. The

data is consistent wit~ a model of pro-deltaic muds of the

Pennington prograding from a source in the central

Appalachians. Further studies are needed to evaluate

this hypothesis.

If the Bangor Limestone is Kinkaid in age, then

a completely Mississippian age assignment for the

Pennington Formation must be questioned. The

Kinkaid Formation is the highest Mississippian

unit recognized from the Illinois basin. Studies

of the Imo Formation from Arkansas and sections

1n the western United States have recognized

calcareous foram zones mssing from the top of the

Mississippian 1n the Illinois Basin. Further studies

of calcareous forams and conodonts from the Bangor

and Pennington are needed to see if the Pennington

is entirely Mississippian 1n age or spans the

Mississippian - Pennsylvanian boundary. Such

studies are needed to determine

biostratigraphically

if a Missi~sippian - Pennsylvanian boundary un-

conformity is present in Georgia or if the sequence

represents continuous deposition across the boundary.

Recognition of the biostratigraphically important

taxa in the Bangor in northwestern Georgia will aid

in better structural interpretations in the Valley

33

and Ridge. Preliminary interpretation of the Risi~g Fawn fauna allowed Chowns and Waters (1977) to delineate thrust faulting along the west and south sides of Lookout Mountain and to confirm a doubled Bangor section on the east side of the mountain.
34

References Cited
Alexander, R.R., 1977, Generic lo~gevity of articulate brachiopods in relation to the mode of stabilization on the substrate: Paleogr. Paleocl Paleoec. 21:209-226.
Bergenback, R.E., 1978, Carbiniferous depositional environments 1n the southern Cumberland Plateau in Field Trips 1n the Southern Appalachians: Tenn. Div. of Geol. Rept. of Invest. 37:63-86.
Brenckle, P., 1977, Foraminfers and other calcareous microfossils from the Late Chesterian (Mississippian) strata of northern Arkansas: Okla. Geol. Soc. Guidebook 18, Miss.-Penn boundary in NE Oklahoma and NW Arkansas, p. 73-88.
Chowns, T.M.(compiler), 1972, Sedimentary environments in the Paleozoic rocks of northwest Georgia: Ga. Geol. Surv. Guidebook 11.
Chowns, T.M. and J.A. Waters, 1978, The Lookout Valley Fault and thin-skinned thrusting beneath Lookout Mountain, Georgia: Geol. Soc. of Amer. Abs. with Prog. 10(4):165.
Drahovzal, J.A., 1967, The biostratigraphy of Mississippian rocks in the Tennessee Valley in a Field Guide to Mississippian sediments in northern Alabama and south central Tennessee: Ala. Geol. Soc. 5th Annual Field Trip Guidebook, p. 53-60.
Easton, W.H., 1943, The fauna of the Pitkin Formation of Arkansas: Jour, Paleo, 17(2):125-154.
Ettensohn, F.R. and D.R. Chestnut, 1979, Echinoderm paleoscology and paleoenvironments from the Glen Dean and Lower Pennington (Chesterian), south-central Kentucky, (abstract): 9th Inter, Carb. Congr., Urbana, Ill., p. 62-63. 35

Gutschick, R.C., 1965, Pterotocrinus from the Kinkaid Limestone (Chester, Mississippian) of Illinois and Kentucky: Jour. of Paleo. 39(4) :636-646.
Horowitz, A.S., 1955, Fauna of the Glen Dean Limestone ln Indiana and northern Kentucky: Indiana Univ. Ph.D. diss., 450 p.
Horowitz, A.S. and H.L. Strimple, 1974, Chesterian echinoderm zonation in eastern United States: Sept. Congr. Inter. Strat. et Geol. du Carb. Krefeld, 1971, Compte Rendu. Band III, p. 207-220.
Lane, N.G., 1973, Paleontology and paleoecology of the Crawfordsville fossil site (upper Osagian, Indiana): Calif. Univ. Pubs. Geol. Sci., v. 99, 141 p.
McLemore, W.H., 1971, The Geology and geochemistry of the Mississippian System in northwest Georgia and southeast Tennessee: unpub. Ph.D. diss., Univ. of Georgia, Athens, GA.
Rodreguez, J., 1960, Invertebrate fauna of the Golconda Formation (Middle Chester) of Indiana, western Kentucky, and southern Illinois: Ind. Univ. Ph.D. diss., 259 p.
Sando, W.J., 1977, The status of North American Upper Paleozoic coral biostratigraphy: Jour. of Paleo. 51(1):1-22.
Scotese, C.R., R.K. Banbach, C. Barton, R. van der Voo and A.M. Ziegler, 1979, Paleozoic base maps: Jour. of Geol. 87:217-279.
Stevens, C.H., 1971, Distribution and diversity of Pennsylvanian marine faunas relative to water depth and distance from shore: Lethaia, 4:403-312.
36

Sullivan, 1942, The geology of the Sand- Lookout Mountain area, northwest Georgia: Ga. Geol. Surv. Infor. Circ., 15, 68 p.
Thomas, W.A., 1972, Mississippian stratigraphy of Alabama; Ala. Geol. Surv. Mono., 12, 121 p.
Thomas, W.A. and H.R. Cramer, 1979, The Mississippian and Pennsylvanian (Carboniferous) systems in the United States -Georgia: U.S. Geol. Surv. Prof. Pap. 1110-H, 37p.
Waters, J.A., 1978, The paleontology and paleoecology of the Lower Bangor Limestone (Chesterian, Mississippian) in northwestern Alabama: unpub. Ph.D. diss., Indiana Univ., Bloomington, IN., 193 p.
Ziegler, A.M., C.R. Scotese, W.S. McKerrow, M.E. Johnson, and R.K. Bambach, 1979, Paleozoic Paleogeography: Ann. Rev. of Earth and Planetary Sci., 7:473-502.
37

Appendix A. Register of Localities Studied.
Locality 1. Exposures of Bangor Limestone along Georgia Highway 143 on the east side of Lookout Mountain. Section measured from highest exposures of limestone approximately one mile along highway; covered intervals were present.
Locality 2. Exposures of Bangor Limestone and Pennington FM on north and south sides of east-bound lanes of I-24 at Paris Hollow, Dade County, Georgia. Stop four from Chowns, 1972.
Locality 3. Exposures of Bangor Limestone, Pennington FM and Fort Payne chert on northeast side of junction of I-59 and U.S. 11 approximately three miles northwest of Rising Fawn, Georgia. Fort Payne chert is faulted over Bangor - Pennington at this outcrop.
Locality 4. Exposures of Bangor Limestone on north side of Tennessee Highway 134, 1.3 miles east of junction with Tennessee Highway 156; 1.6 airline miles from old Haletown on south side of Raccoon Mountain, Marion County, Tennessee. Stop one of Bergenback (1978).
38

Locality 5. Exposures of Bangor Limestone 1.5 miles south of Rising Fawn, Georgia, on the west side of U.S. 11. Small outcrop containing Caninia and Caninostrotion.
39

EXPLANATION OF PLATE 1. (All figures xl.5 except figure 8 - x2)

Figure 1.

Pterotocrinus tridecibrachiatus Gutschick wing plate from Bangor Limestone residuum at locality 3, Rising Fawn, Georgia.

Figure 2.

P. edestus Gutschick wing plate also from locality 3 .

Figure 3.

~ pegasus Gutschick. Broken wing plate from locality 3 . P. pegasus is rec~gnized from lateral thickening of wing plate peticle.

Figure 4.

Pterotocrinus ~ calyx. Probably ~ tridecibrachiatus as it had thirty arms. Thirty armed Pterotocrinus ~ are khown only from Kinkaid age equivalent formations. Calcyes for P. edestus and ~pegasus are not known.

Figure 5,6. Caninia ~ 5. oblique cross-section of large trochoid solitary coral showing septa and dissepiments; 6. longitudinal section showing tabulae and dissepimentarill,In_._, Both specimens buried in dolomitized micrite.

40

Figure 7.

Caninostrotion cf. c. variablis. Acetate peel of longitudinal section of fasciculate colony embedded in dolomitized micrite (locality 2). Tabulae are entire and dissepimentarium wide near apex. C. cf. variabilis was found at localities 1, 2, and 5 and apprently lived in tidal channels in the tidal flat environment.

Figure 8.

?Caninostrotion sp. Cross-section of colony from locality 2 in micritesparsely fossiliferous micrite. This specimen possible referable to Campophyllum gasperense of Butts.

Figure 9.

Oobiosparite from locality 1, bed 6, sample 12. Characteristic of many high energy oolite shoal.

41

PLATE 1

42

3

7

r

Figure l.

EXPLANATION OF PLATE 2; (All figures xl.S)
Caninostrotion of C. variabilis. Oblique section of fasciculate colony is dolomitized micrite Uocality 2). Corallite in lower center bedding to produce new corallites. Tidal channel part of the tidal flat environment.

Figure 2.

Transition between dolomitized laminated micrite below. and echinoderm biomicrite above. Thin beds of echinoderm debris in micrites show intermittant increased current activity. Locality 1, bed 4, sample 7. Tidal flat-lagoon transition.

Figure 3.

Peloobiosparite; medium to coarse grained oolitic echinoderm packstone; poorly sorted; mature and superficial oolites, fenestrate bryozoans, high spired gastropods, calcareous forams, ostracodes, pellets. Locality 1, bed 23, sample 23(1). Oolite bar - lagoon transition.

43

Figui'e 4.

Medi~ gi'ained echinodei'm gi'ainstone with oolitic coatings; modei'ately soi'ted; oobiospar,ite; few bi'yozoans and calcai'eous forams. Locality 1, bed 10, sample 17. Subtidal shelf - oolite bar transition.

Figui'e 5.

Dismicrite. Locality 1, bed 20, sample 20(1). Tidal flat environment.

44

PLATE 2

45

2

1

3

4 5