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1942 The Geology of the Claiborne (Eocene) Group of Mississippi as Far North as Grenada County. Emil Paul Thomas Louisiana State University and Agricultural & Mechanical College

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Recommended Citation Thomas, Emil Paul, "The Geology of the Claiborne (Eocene) Group of Mississippi as Far North as Grenada County." (1942). LSU Historical Dissertations and Theses. 7854. https://digitalcommons.lsu.edu/gradschool_disstheses/7854

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LOUISIANA STATE UNIVERSITY LIBRARY

119-a

THE a^Q im x OF TBS GUXBOIWS; (ECC3KSS) G SW OF

MISSISSIPPI AS FAH KORTH AS gltSHABA W R IT

A Dissertation

ubmitted te the Graduate Faculty of the Louisiana stats University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in

The School of Geology

By 3toiI Paul Thomas , Oklahoma a g r ic u ltu r a l and Mechanical Co lieg e# 193 M« 3*# Louisiana atate University, 1939 June# 1943 UMI Number: DP69232

All rights reserved

INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted.

In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion.

UMI Dissertation Publishing

UMI DP69232 Published by ProQuest LLC (2015). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code

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ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 ' ■ ' £ " ■ 3 r _ h i \ 'i Clt \

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SP *6063 rS.) ACKWC'VLSuaM^T

This ripert is based upon field work which was dsns for tbs

Obis Oil Company sad it is through tbs generosity of tbs company and tb s bind in te r n e t s f Iir* C* X* Moody and Mr* W* B* JSasry si* i t s geological staff that tbs papsr was mads possible* Dr* H« M* Fisk has been particularly helpful in checking tbs field work and criticising tbs manuscript* era* 1* V* Bows* R* J* Bussell* R* 0*

R u sse ll, 0* J# Boy, J* M* HeQuirt and Mr* C* I** Moody bars a l l given oonstrustivs criticism* Miss Jans isulston Huggins has ably edited tbs manuscript*

i i TA81& OF O-imWTS

Fag# ABSTRACT v i i i NTRGBUCTXOH X

S3K3IiAn FSATUR3S OF TBS AMA MAPPSD 2

FHY8XCCRAFHY 4

CL/ilBORNS STRATIGRAPHY 6

Introduction 6 Tallahatta Formation 10

Basic clayston© member 10

Hesii&ba sand member 19

.inona Greensand 24

Zilpha Sbal® 30

Kosciusko Formation 38

/autubbee Formation 4b

introduction 4b

iirchusa marl member 47

rciterchitte member 50

Gordon Creek shale member 5b

Undifferentiated autubbee of central Mississippi 57

Shipp's Creek shale member 59

General features of the /autubbee formation 64

Coekfieid Formation 68

i i i 3-UTIC&LHIF OF TH3 CLAIB0M2 OF MiSSISLIIFl 1'G f&

CLAIBCKKS SICTXOK

Introduction

Tallahatta Formation

Lisbon and Gosport Formations

Introduction

inona equivalent

Zi lpba equivalen t

Koeeiueio equivalent

autubbee equivalent or typical Lisbon fa c ie s

Coefefield equivalent

YCLIG LSFOSli'XGBAL r*iTTSKK LIST OF PLATES

Flat® I Geo logical Map of the Claiborne Group of In back poeket

ississippi ae Far Forth as Grenada County

F la te 2 Composite Diagram Showing Facies Changes xn back pocket

and Thicknesses in the burfaee Claiborne

Section .cross Mississippi

LIST uF FIGURES

Fig* i Tabular summary of the Hist cry of Claiborne In back pocket

Nomenclature in Mississippi

Fig* 2 Diagram Showing C orrelation of Claiborne Group Page 76

of Eastern Mississippi with Type Claiborne

section of eetern , labeuaa

LIST OF FKGFIL3S

F re fi le A Geologic Irofile along highway ti* l* 4b .n back pocket

From Meridian to Quitman» Glarko and

Lauderdale Counties, Mississippi p ro file B Geologic irofile along highway U* L* 11 In back pocket

frcm Basic City tc Vachuta, Clarke

ana Lauderdale Counties, Lise*

P rofi le C Geologic irofile along state Highway 15 In back pocket

from Philadelphia to Newton, Neshoba

and Newton Counties, Mississippi

I ro fi le D Geologic Irofile along State ii.ghw&y 12 In back pocket

from near It he I to Lc^deuns> a t ta la

County, Mississippi

v ^ r o fi le Goolegle Profile along Highway U* s* 88 In back poeket

from Kilmichael to tho Bluffe, Carroll

ana Montgomery Counties’, M ississippi

Vi abstract

The Claiborne group of Mississippi is divided into six formations in this report* They are (youngest to oldestji Cock * field, autubbee, Kosciusko, Zilpha, inona and Tall&hatta* The

^autubbee formation is subdivided into three new members in eastern

Mississippi* They are (youngest to oldest)s Gordon Creek shale,

Potterchitto member and Archuea marl* This subdivision is not practicable in the central part of the outcrop belt and the forma­ tion is net differentiated there* The marine autubbee lenses out into non-marine eanda and shales in southwestern Attala County, but its non-marine extension, the new Zhipp'e Creek shale, is recognised as far northwest as the alluvial valley of the Miss­ issippi River* The Tallahatta formation is divided into the Basie claystone member and the new Neshoba sand member in the eastern and central parts of its outerop belt, but this subdivision be­ comes in fe a sib le in Grenada County and the formation ie not d if­ ferentiated there* The other four formations are not subdivided*

The history of the terminology, original definition, lithe logy, contact relationehipe, distribution, topographic expression, soils and depoeitional conditions of each of the lithologic units are discussed* The areal distribution of the different formations ie shown on the geologic map (Plate 1} and the facies changes along strike are ehown on a composite diagram (Plate 2)* These two

v ii plates combined, give all of the essential features of the Claiborne group in the area mapped* Five surface profiles are also included*

each of the Claiborne formations of clissiesippi has a lithe logic equivalent in western Alabama* the stratigraphic re­ lationships of the Claiborne beds in that area are discussed briefly and tentative correlations with the type Claiborne section are made*

The Claiborne group of central and eastern Mississippi ex­ hibits a cyclic depositions! pattern which iss

con-marine sands and shales (top)

carbonaceous shales or transition facies

marine facies (bottom)

Dieconform!ties or stratigraphie breaks at which there is evidence of erosion occur at the base of each marine section» while all other contacts are conformable* It is believed that thie pattern is caused by subsidence under load and epeirogenic movements combined*

v i i i The Claiborne group is one of the four groups which constitute the Eocene series of the Tertiary system of the southeastern united

Statoo* This report covers most, hut not a il, of the Claiborne of

Mississippi* la recent years it has become apparent that the lower

Claiborne beds extend much farther north than is shewn on the state geological sap of 1926 (1}« It is probable that they will be found to extend to the northern state line* These beds were mapped only as far north as the northern Grenada County line during this work#

(1) L. w* Stephenson, w« K* Logan and G« A# v/aring, "The Ground-water Kesources of Mississippi," U. c* Geoi* curvey a te r supply Paper 576 (1928), p la te 2. * * ------^ ------The area mapped eevere approximately 6,000 square m ilee and includes all or part of fifteen counties situated in the centraI part of the state of Mississippi* its general outline and position are sheen on the geological map (Plate i}« The area is a belt crossing the state from the Missiesippi-Aiabama state line on the southeast to the alluvial valley of the Mississippi idver on the northwest* It averages about £Q m iles in width a t the Alabama lin e , gradually increases northwestward to a maximum width of 60 &iiee across Attala and Holmes Counties and then decreases northward to about 20 miles i s width in Grenada County* This area was mapped in a th irte e n months* period beginning in the spring of 1940* All of it was covered by the writer except the Claiborne outcrop area of northern i adisen County which is taken from a map by r* 0* L* koedy and is included in order to make the regional map complete*

Xbe Claiborne outcrop pattern reflects the regional structure*

The normal strike of the beds in the extreme southeastern part of the area is about 50 degrees west of north* The strike of the basal

Claiborne contact gradually changes northwestward to about 10 degrees west of north in renada County, while the strike of the upper contact averages about 35 degrees west of north all the way across the state*

This difference in strike reflects a marked northwestward thickening of the Claiborne section from about 330 feet at the Mieeiesippi-Alabama 3

state lino to mere than 1200 foot at the edge of the alluvial valley of the kieaieelppi River* The normal dip is to the southwest and west* it ranges from 25 to 33 feet per mile, being steeper on the lower beds than on the upper* xHTS'XOQBM'HY

The Claiborne group outcrops la two physiographic regions* ihe greater portion ©f the outcrop lies in the area generally known ae the Hearth Central Hills* a well-dieeected ©and hills upland broken by several pronounced ©uestas and escarpments which follow the strike of the beds* The local relief varies from SO to 300 feet and is greater on the outcrop of the beds in the lower part of the Claiborne section than on these in the upper* The beds are well exposed throughout the area except along the western border where an exten­ sive blanket of brown silt often obscures the outcrop* The only other superficial deposits are the recent alluvium and quaternary terrace materials along the streams*

The a©conet physiographic region in which the Claiborne beds outcrop is commonly called the Loess Hills* This is a region of rugged topography which forms a b e lt from b to I Z miles wide along the western border of the Claiborne outcrop* The Tertiary is covered by thick deposits of quaternary sands and gravels and loess throughout the area* The Loess Hills adjoin the alluvial valleyof the Missieeippl iver and are sharply defined on the west by a continuous series of bluffs which rise abruptly above the valley floor* The typical Loess Hills topography marges with typical sand hills topography eastward and the ©astern boundary is arbitrarily taken ae the eastern limit of the quaternary mantle deposits mapped 4 Si* q ®u Fiat® u T ertiary ®xj>®e»r®» ar® Touad ©aiy aiea g th® stream©

Aa raviaee aieag th® bluffs Aa this r®gi©at bat they iaeiud® some e f th® b eet exp©ear®e i a th® etat®* Qteimm& zrzm m m i INTRODUCTION

The tera Claiborne U) was first used by Conrad in 1847 for th e "Claiborne sand" exposed a t Claiborne Bluff* Alabama from which he had described a number of foesils# He assigned it to th© "Lower

e r Older Sosen©”* H iigard f i r s t id e n tifie d the Claiborne group in

Miesieeippi in I860 and divided it into aa upper "Calcareous

Claiborne group1* and a lower "Siliceous Claiborne gr0Up«# Beven

year© later he excluded the "siliceous Claiborne or Buhrstone"

from the Claiborne proper and his restricted definition me used

until 1894 when Harris included the Buhrston© (Tallahatta formation

of later reports) in his "Lower Claiborne stage"* the United

States Geological Survey has included the Tallahafta formation

in the Claiborne group since 1906*

as new generally accepted* the type Claiborne section is

divided into three formations in the area around Claiborne Bluff,

Alabama* They are*

Gosport foeeiliferous sand

Lisbon sandy marl

Tallah&tta formation or "Buferetone"

(2) M* Grace ?ilmartb, "Lexicon of Geologic Kamos of the United States (including Alaska),** U. £. GeojL* Survey Bulletin 893 (1938)* pp# 448-449.

8 7

The group le overlain by the Jackson formation (uppermost geeeae) and le underlain by the lleox group (middle Soeene)*

Figure I le a tabular summary ©f the history of Claiborne nomenclature in Mississippi* It skews that the more modern writer®

hare divided the Claiborne of M ississippi into three formations which correspond to the three ferotations of the type Claiborne section of

Alabama. They area

C oekfieid or Yegua form ation

Lisbon formation

Tailahatta formation

In this report the Lisbon formation of these authors is

subdivided into four formations because it is composed of several stappable units which can be traced across the state* The Claiborne group 9 then, consists of six formations* They arei

Coekfieid formation

/autubbee formation

Kosciusko formation

Zilpha shale

Winona greensand

Taiiahatta formation

The Coekfieid formation ef this report includes all beds above the predominantly arine autubbee formation and below the marine basal Jackson (Moody's Branch formation)* The marine

Wautubhee form ation i s subdivided in to three new members in eastern

M ississippi, is undifferentiated in central M ississippi> and is extended northwestward into the »o«~marine Shipp’s Crook shale member of this report* The Kosciusko formation includes all bods above the Kiipha shale and bo low the Mautubbe© formation* The tom s

Zi. ip ha and inema are used as originally defined by Moore (It 40} and

Love (19it), respectively* The Tallahaita formation is aividad into the Basie elayetone member ( Lowe, 1919) and a now member, the Meeheba sand* The Meridian sand, which is considered basal Claiborne by the

Mississippi §eological Survey, is excluded from the group*

These subdivisions are shown graphically on H ate S, which is a composite diagram shewing changes of facies and thicknesses ef the different femotions along strike from the Hesissippi-Alabama state line to the western and northwestern limits ef the area mapped*

The plate is necessarily highly diagrammatic because it is impossible to show the true complexity of the section on a two dimensional figure* It is constructed from data obtained from highway profiles, measured sections, surface contours, well information and reeonnais* sanee mapping* The plane to which all data are referred is the

Z iIpba-Tinena contact, the most persistent and reliable contact in the Claiborne section* Horisontal intervals on llate % represent distances along the normal strike of the datum plane, while vertical intervals indicate thickness of section* The geologic section shown along any given vertical line is the approximate section which would be shown by a surface geological profile run perpendicular to the normal s trik e of the datum plane from the point where the v e rtic a l line crosses that plane* The towns and villages and a few localities on the outcrop are shown beside vertical arrows which indicate the g eological section exposed, in and around each*

When properly interpreted, Flats 2 shows all ©f the essential elements of the Claiborne group in the area mapped* .& set of examples showing the use of the figure is taken from the area around the town o f Newton, Newton County* The p la te shows th at the geological section exposed in and around the town ranges from the uppermost few feet of the Wautubbee to shout 60 feet up in the Coekfieid* It indicates that the autubbee section near lewton is about 90 feet thick and is d iv is ib le into th ree fa c ie s o r members and th a t along the s trik e northwestward the formation changes facies and becomes thinner* The figure also shows that in the area between Newton and Decatur the

Vautubbee section and th e upper h alf of the Kpseiuek© section are exposed and that between Decatur and Neshoba the lower Kosciusko, a rather thick section of Zilpha shale with a greensand bed at the top, the inona graensand and the Neshoba sand are exposed*

Five selected surface geological profiles run along main highways traversing the Ciaibern© outcrop belt are also included*

Their primary purpose le for use in inspecting the Claiborne in the field* Nearly all ©f the essential features of the section are shewn on these p ro files* 10

'iA U A S U ra FORMATION

introduction

The same Tallahatta first appeared in print in an article by

Dali (3}.# I t was suggested to him by B* A* Smith t© take the place

o f the term "Buhrstone* which had a lithe logic, rather than a geographic, connotation# The term Tallahatta has been in general use in Mississippi since its introduction by Johnson in 1905 to replace Hilg&rd'e term ^siliceous Claiborne**

The typical Tailshatta "bubretone* section, herein called the Basic claystone member, is well developed throughout eastern

Mississippi, but in the central and western portions of its outcrop the typical facies is largely replaced by a sand section called the fteeboba sand member* In the extreme northern part ©f the area mapped the entire section changes facies and is called undifferen­

tiated Tallahatta formation in this report*

C lactose 8»*»tr Introduction - The Basie claystone member is th© stratigraphic and iithologic equivalent of the type section of the Tallahatta forma­ tion of choctaw County, Alabama* The term Basic is used for this

section in preference to Tallahatta because it was found necessary to set up another member in Mississippi and the two members together

logically constitute the Tallahatta formation# The name Basic is well established in Mississippi literature, having been proposed

(3) 7# H* D a li, "A Table o f the Morth American Tertiary Ho ricone, Correlated with One Another and with Thoee of Eastern '‘mi0^ ! i0n8*" Si* *♦ 2*ai* § a sm . M in &sa* Ma£*. p t. 2 (1 8 9 8 ), p . 344* 11

by Lowe is 19id (4) and ueed since is several Mississippi Geological

Survey bulletins* The type locality is a deep out en the railroad

juet north of Basic City, a railroad station is northwesters Clarke

County* Mieeieeippi* as shown os profile Bt a full section SO feet

is thickness ie exposed is this issnediat© vicinity# Xt overlies

the micaceous* ligaitic sands of the uppermost Wilcox (Meridian)

and ie overlain hy the Winona greeneand#

blthoiegy - The Baeie member has the most distinctive lithe logy

ef any ef the beds ie the Claiborse section ef Mississippi# Xt ie

composed chiefly ef siliceous elaystone with intorbsda of siliceous

siitetene and sandstone* These indurated rock© are the “bubrsiens”

ef the elder authors* Buhrstone is any siliceous rock suitable for

use as a millstone* Very little of the material in the Baeie could

be so used and the tens "buhreteae" has been so loosely applied that

the tendency ef the mere recent authors has been to drop it from the

literature#

The e lay stone of the Basie feme by surface induration from

a dark greenish gray* somewhat micaceous, silty clay that usually

contains scattered plant fragments* The indurated material le a

light-colored, brittle rock which is remarkable for Its low specific

gravity and which breaks with a sub«*ccnehoidai fracture# The con­

traction caused by the evaporation of the connate water shatters

the elaystone into angular blocks the surfaces of which are usually

(4) J3« N* Lowe, “Mississippi, Xt© Geology, Geography, Bell© and Mineral Resources,** Miss# Geo I, Survey Bull* 14 (1919), pp* 74-75* 12 stained yellow-brown and which commonXy exhibit a regular concentric banding extending to the center of the block* The claystone commonly contains email lenses, angular inclusions and fuooictai etrueturee of glauconitic silt which impart a heterogeneous texture to the sediment*

The siItstone interbeds of the Basic member are formed by surface induration of a dark greenish gray* lignitic, argillaceous* glauconitic, micaceous* coarse grained silt* They are also light in color and often stained by iron oxide* The siltstenes are usually irregularly indurated and have a characteristic knobby appearance on the outcrop* Inclusions of clay and sand similar to the inclusions in the clayetone are abundant*

Sandstones are the leaet common ef the indurated beds in the Basic* they are similar in general appearance to the si listener and range from fine grained to coarse grained* They vary from highly glauconitic to non-glauconitic and from semi-indurated to quartsitic*

Bhale or blccky clay similar in litho logy to the fresh clay from which the cl&ystone arises but lacking the property of becoming indurated upon exposure is abundant in the Basic* &reensand (5) occurs rarely in the member in the form of thin stringers which are found both at the top and at the bottom of the section*

Throughout eastern ksiseiesippl the base of the Basic member

(5) The term "greeaeattd* is used in this report for a eand which contains ever 15$, of glauconite grains* Glauconite-bearing sand containing lees than that amount is called "glauconitic sand*** 13 is marked by a bed ef co&rse grained* poorly sorted, light greenish gray glauconitic ea&d with an abundance of white quarts granules and small, rounded quarts pebbles* This basal sand of the Basic ranges up to IQ feet in thickness and grades upward through a glauconitic sandy clay or shale into the overlying indurated material*

The structure of the Baeie member is even-bedded and thin-bedded ie thick-bedded, the different facies being interbedded throughout the section* The beds are extensively jointed on the outcrop and large, vertical, dike-like bodies ef clayetone are occasionally seen cutting across the individual beds*

in Newton and Neshoba Counties lenses of nen-glauconitic sand become abundant in the Basie* This material is stained red, brown, yellow, pink and purple on the outcrop and is fins grained, micaceous and well sorted* Its structure varies from massive to cress-bedded*

P e lle ts , p artin g s and strin g e rs of gray clay occur in this? sand*

The characteristic indurated Basic materials become progres­ sively thinner and mere lenticular northwestward along the strike u n t il , in northern Montgomery and Grenada Counties, the only remnants are a few local developments of soft, white glauconitic si listen®*

Interbedded with this si listens and lying both above and below it in Montgomery County th ere ie found a d istin c tiv e black, carbonaceous, silty, micaceous, fisele shale which dries out into a very light gray or white, e lightly indurated flaky shale* kssociated with this flaky shale are partings, stringers and interbeds of micaceous, sparingly glauconitic to non-glauconitie silt and sand* These flaky shales and associated beds reach a maximum thickness of IQO feet in the hills ewet of Grenada, Grenada County, and constitute at least part of Lowe*s Grenada formation which was long considered to be of upper 14

file©* ago* This relationship was first pointed out by the authors of the Claiborne and '?!lee* Field Trip Guidebook of the Mississippi

Ceological seciety (March, 1940)* If this shale section is persistent northward from Grenada County, the Grenada beds should be considered a member of the tallahatta formation*

In Grenada County the flaky shales are overlain by 3 to 30

feet of light greenish gray glauconitic sand ©r greens&nd which ia

characterised by an abundance ©f fucoidai structures and small clay inclusions* These glauconitic beds should be given the rank of & new member in the Tallahatta formation if they are persistent north* ward* until more detailed work is done between Grenada and the uiasissippi-Tennese®® state lino, it is considered preferable to

leave the Tailahatta section undifferentiated in Grenada County*

Lower Contact * In th is report the base of the Claiborne group is placed at the base of the Basic member* The Mississippi

Geological Survey, following Lowe (6), places it at the has® of the

Meridian sand, a non-marine sand section which underlies the Basic throughout the area mapped* The Meridian sand is named from exposures near the city of Meridian, audordale County, Mississippi and was considered to be a member of the Tailahatta formation in state survey publications until Foster (7) recently raised it to

S. Hi* Lew©, "Midway and Wilcox Groups" in wCoastal I lain Stratigraphy of Mississippi, Part First," Miss. Gaol* purvey §EiA» 25 (1933), p* 1 and pp. 106*106*

(7) V* M* Foster, "Lauderdale County Mineral Resources,” Miss* G©ol» Sttrvey Bulletin £i (1940), p. 68* 15 formation®I rank* i t i» a maeeiv© to highly ereee-be&ded, l i gn.it! c to ncB-iignitie sand which ranges up to 135 feet in thickneee and which contain® a few lessee of glauconitic sand* greenaand» glau­ conitic sandy shale and llgniflc silty shale in Clarke and Lauder- dal© Counties* The reasons for excluding the Meridian sand from the Claiborne group ares

1* It is lithologically much more similar t© the underlying non-marine 1 lcox than to th© overlying marine iallah&tta* it was deposited under conditions very similar to those which prevailed throughout most of Hcox time In the eastern Mississippi area*

2* The marine Tallabatta section overlies th© Meridian sand with distinct disconforraiiy throughout eastern Mississippi and western labama#

3* The lower Meridian contact change® over short distance® along the strike from conformable to locally dieconformable (local erosionai channels}*

The lower contact of the Basic member is dl©conformable as far northwest as the earl Mver in Meshoba County# The detail® of the contact and iithology of the underlying ana overlying beds indicate that it represents a email erosionai and chronological break in which the uppermost few feet of the low-lying fceridian deltaic plain deposits were truncated by wave-erosion during the advance of the Tallahatta sea* The contact itself is sharply defined, the change from non-marine to marine facies occurring within 6 inches to 2 feet of section in which the two facie® are intimately mixed*

Small blocks and fragment® of llgnitic shale and quart® pebble® 16

from the underlying bed® are found in tbe basal fen feet of the marine

section and branching fueoid&i structures from the feed® above extend

a foot or two down into tbe underlying non-marine sand# The basal#

pebble-bearing glauconitic sand of the Basie member in eastern Miss­

issippi apparently represents a beach deposit thrown up by the waves

along an advancing shore*line* The continuity of this deposit indicates

& strong, unbroken advance throughout the area, Near hi ladeIphia,

teshoba County, there is a 10 foot lens of Basie material lying

about 10 feet below the main body of the member# It also has a

basal, pebble-bearing sand and probably represents marine materials

deposited in a email estuary on the meridian deltaic plain ahead of

the main advance of the Basie sea#

northwestward from the rear! River the lower contact of the

Basic somber becomes quite gradational and shows l i t t l e evidence of

an eroeicaal break# The basal, pebble-bearing sand is not developed

and the transition from non-marine to marine facies occurs through

6 to BO feet of interbedded glauconitic sand, non-glauconitic sand,

carbonaceous shale and Basic-type clay# The marine advance was apparently net b o strong in this area and this contact probably

represents a gradual replacement of non-marine deposition by marine

deposition* in the Montgem©ry-Grenada County area the lower Tal­

lahatta contact is conformable# The flaky shales which lie at the

base of the Tallahatta section grade downward into the underlying

Meridian eand through an interbedded eand and shale transition facies

which ranges up to 10 feet in thickness# This contact represents an

even more gradual change from non-marine to marine conditions. 17

The Basic ©layetone member average a about 60 feet in thickness in eastern Mississippi* Its range in thickness in that area is from 50 to 115 feet* These figures are comparable with the thickness of the fallabatta formation in western Alabama where the average is 100 feet and the maximum is 125 feet* In the central portion of its outcrop the Basie member becomes thinner and the thickness varies greatly over short distances along the strike# The range in thickness here is from 10 to @0 feet and the average is about 5g feet* Through southern and cen tral Montgomery county the thickness varies from 5 to 30 feet* In the area around Grenada the thickness of the undifierentiated Tallahatta section reaches a max-* imum of about kcQ feet*

Cossi Is * Ko detailed paleontological work hue been don® on the Basic member* but it is apparent that it contains a large fauna*

Host of the finer grained rocks contain mold® of thin-eheiled mol"** luges* but no localities were found where fresh fossils could be collected* Many of the fossils in the claystone are cpaiiced*

Grim (8 ) records both diatoms and radiolaria in his thin sections*

Pietribution - Gee distribution of the Meehcba eand on page 21*

Topographic Sxureeslcm - The Basic claystone member forme the strong Bttbretene Cuesta (9) in eastern M ississippi* Along the baj&da or steep side of the cueeta there is found some of the most rugged

(6 ) K* 2* Grim* "The Eocene bediments of Mississippi*" Miss* Geo I. survey Tull* 3U (1936)* pp. 152-153* (9) Um dm iTenneman, i hyaiggrapjay of the GasMpt y.n£AM sta te s (Hew York* McGraw-Hill* 1936)* p# 75. 18 topography in tbe entire Coastal > lain Province* Tbo local relief averages about 175 foot and ranges up to 300 foot* On tbo gentle slops of tbo cuesta typical sand bill# topography developed on tbo overlying Kosciusko sand is superimposed upon the more rugged clay- stono topography and the average local relief is about 75 feet# This cuasta becomes progressively lees pronounced northwestward aleng the strike as the claystone becomes thinner until, in the northern part of the area mapped, it is absent to very weakly developed*

Soils - The Basic claystone gives rise to fine sandy loam and stony clay soils of the auderd&ie series* They are among the poorest agricultural eoiie formed on the Claiborne outcrop in sties-

1 seippi*

Depositions! Conditions * The presence of the mineral glau­ conite and of marine fossils are generally regarded as prime facie evidence for & marine origin of the associated sediments* ihe Basie clayetone alee exhibits ether features which are indicative ef marine deposition among which are the persistence of the facies over 200 miles along the strike, the thin-bedded, even-bedded structure and the abundance of fucoidal structures* ione of these features are common in non-marine sediments in the Tertiary system of Mississippi*

The thin-bedded, ieterbedded nature of the tain body of the

Basic member indicates that it was deposited in quiet water in a position near enough to tbore that slight changes i n the grain size of the sediment introduced into the sea were recorded in the inter- bedding of the clays, silts and sands* This depeeitlonal activity was interrupted in the central part of the outcrop area by the intro- 19 ductien of largo quantities of sand now incorporated in the section a s tbe Neshoba sand#

Tbe undifferentiated Tallahatta section of Grenada County was deposited under nearer-shore conditions than the Basie* The flaky, carbonaceous shales of the lower part of that section are probably coastal wared deposits (see Deposit!oneI conditions of the

ilpha shale}* The deposition of these materials was followed by an encroachment of the eea over the coastal marsh and the deposition of the overlying g lauconitic sand and graens&nd*

ihe siliceous cement which binds the rocks of the Basic is apparently primary* since it is quite uniforaly distributed through

1GG feet of sedi.usnte in eastern Mississippi* It was probably pre­ cipitated froia the sea water under relatively quiet conditions*

Neshoba «to*iMiMk* Band Member tftn**»«»«*J*v*a» Introduction - Overlying tbe Basic claystone and underlying the Tinona groeneand throughout the central and northern portions of the area mapped* there is a section of non-giauconitie to sparingly glauconitic eand which has heretofore been considered to bo lower wineaa* This eand section is a useful mapping unit and it is herein named the Neshoba sand from typical exposures in and around the vil­ lage of Neshoba* Neshoba County* The type section is designated as that shewn lying above the Basle claystone and below the Winona groeneand on Profile C along the present highway through Keehoba*

Tbe Neshoba eand i s considered to be a member of the T alla­ hatta formation because*

U It is the stratigraphic equivalent of part of the typst ZQ

Basie clayeton© section and si part of tbe type Tallahatta section of Choctaw County| Alabama* This relationship is illustrated on

P late 2 where tbe overlying Winona greensand is shewn maintaining a constant thickness and lithelogy across the area where the Neshoba lenses out into the Basie*

2* The ^eehoba eand is overlain and underlain by typical

Basie material in Newton and Lauderdale Counties*

3* The Keshoba and Basie facies are intimately interleaved over a wide area and the thieknees of the fteeheba flaetuatee in­ versely with tbe thieknees of the Basie* A t bo logy - The Kesboba sand i s composed o f ncm -glauccnitic to sparingly glauconitic, nen-foseiliferoue* marine sands which are typically well sorted, fine grained and micaceous and which vary in structure from massive to irregularly bedded to cress-bedded* hen fresh, the sands are white, but on the outcrop they are usually stained red, brown, yellow, purple and mottled* Tbe sands in the upper 5 to 15 feet of the member are normally quite different in appearance from the sands in the remainder of the section* They are dark, brick red in color, highly argillaceous?, medium grained and poorly sorted* Their high clay content and dark color are derived from the overlying weathered '.Viacom greeneand through the action of percolating ground-water# Qreeneands and glauconitic sands are occasionally found in the liesheba* They are local concentrates of glauconite which grade laterally and vertically into non-glauconitic sands* Gray clay is abundant in tbe i eehoba la the form of pellets, partings, stringers and lenses in the sands* impure bentonite and 2.x bentonitic clays are found at or a oar the top of the member in Attala and Grenada Counties* In northeastern Newton and northweetern xauder* dale Counties thin* discontinuous lenses of typical greenish gray*

Basic*type slay and shale occur at the top of the matcher* in northern Montgomery and Grenada Counties the tteebeb* section thine and shews a decided change of facies* Carbonaceous clays and shales become abundant as lenses and partings in the glauconitic to ncm-gi&u- eenitic, micaceous sands and silts and at a few localities discontin­ uous* Basie*type siltstone ledges occur within the section* These sands and shales are included in the undifferentiated Taliahatta section of Grenada County*

Lower Contact * The Beshoba sand lie s conformably upon the

Basic claystone* Throughout the central part of the Taliahatta out* crop belt, the red sands of the Neshoba usually rest directly upon typical Basie clay or shale and occasionally they lie upon eliteton© or sandstone* The contact ie normally sharply defined* there being no ieterbedding of tbe two facies* In the Uontgomery-Granada County area the contact is more gradational and ie usually marked by an interbedding of the two faciee*

Distribution * The outcrop areas of the Basic claystone and

Neshoba eand members are grouped together as Taliahatta formation on the geo logical map (Plate 1) because its email sea le limits the amount of detail which can b? shown* a study of Figure© 1 and 2 in conjunction will give the approximate distribution of the two facies*

In northeastern Clarke and southeastern Bauderdaie Counties the Basle constitutes the entire Taliahatta formation and the outcrop area is 22 ft very narrow and irregular belt with numerous topographic outlier© which reflect© the marked development of the Buhrstone Cueeta and the sharpness of the bajada in that area* Northwestward along the strike the Tallahatta outcrop widens to an average width of about 6 milee and becomes lees irregular and the Neshoba eand outcrop area becomes predominant over the Basic outcrop area*

Topographic jtanrseeion * Throughout meet of its outcrop the

Neshoba eand gives rise to a rugged eand hills topography in which the local relief average© about ?S feet* £ la rations on this outcrop are in general quite high because it lies between the strong Buhr- stone Cue eta on the east and the we Undeveloped cuesta on the jinona groeneand to the west*

Soils - The Neshoba sand gives rise to loose* light gray or

lig h t brown fin e sandy loam and fin e ©and ©oils* The to p -so il range© up to I foot in thickness and the sub-soli* which is a reddish brown or mottled clayey sand or sandy clay* ranges up to 6 feet in thickness*

Tbeee soils are mapped as *uston or some closely allied soil series* such aa Greenville* crangeburg or Norfolk* They are fairly good soils for general agricultural purpose©*

^©positional Conditlens - The manner in which the Neshoba sand is interleneed with the Basic claystone* the slightly glauconitic nature of the beds ana the canformable nature of the lower contact indicate a uariaa origin for the Neshoba* The irregular bedding and crces-bedaing point to a near-snore s ite where current© were active*

curing the time in which the upper Basic clay® and silt© were being deposited in eastern iiieeissippi* an abundance of sand was intro- 23 dueed in tbe sea in the central and northern parte of the area mapped and wee ineorporated in the section as the fteshoba* Conditions in the Keehoba sea were unfavorable to the precipitation of siliceous material, probably being toe near-shore in agitated wafers* -ither marine life was impoverished in the eohoba sea or condition® for its preservation were extremely unfavorable because there is no fossil evidence of its existence* WIIKSiA GE3SWSANB

Introduction * The name inona w&® proposed toy low® {AOJ in IS 19 for groeneand® which are well exposed near the town ©£ Winona,

Montgomery County* Hie o rig in a l d e fin itio n iea

"The ?inena eand a® found, in the western part of it® outcrop, especially well developed around Winona, Vaiden and eastward into adjacent counties, consist® of highly glauconitic sands and clayey eand® that weather to an intense Indian red color where exposed at tbe surface* This material is marine in origin and locally abundantly £ oeei liferous* On tbe Southern Railroad tooth east and west of Winona, are characteristic notable deposit® of this material, that at Elliott, th re e m iles east of Winona, toeing esp ecially striking* From Winona southward on the Illinois Central Railroad frequent outcrepe of the material are seen a® far south as ¥aiden and Beatty* The thieknees of this division of the Ifeliahatta in northwest Mississippi is estimated to toe approximately 350 feet *11

Although Lowe's estimated thickness is several times too

high and the upper and lower limit® of the inorm are not drawn,

the description of the lithology and tbe localities mentioned satis* factor!ly delimit the formation*

Lowe erroneously considered the inona to toe the lower member

of the Tallahatta formation and correlated it with the Meridian eand of eastern Mississippi* lie (11) had previously applied the name

Enterprise to a greensand exposed in the town of enterprise* Clarke

County, and had considered it to be the basal member of the Lisbon

formation* Cooxe (IB) was tbe first to recognise that the greensand®

(10) E* K* Lowe, "^iesiesippi, It® Geology, Geography, Roil® and Mineral Resources," foies* Oeol* survey Bull*. 14 (1919), p* 73*

(11) 2* K* Lowe, "Mississippi, Its Gee logy, Geography, doll® and Mineral .©sources," Mle ^ Geelf Guryev Bull* Ik (1915}, p* 76*

( Ik) C* tfythe Cooke, ' Correlation of the ocene formation® of Mississippi and ;* lab sm a,” U*. USSIil S tm X . t£g£s. L&fcg£ 142=1 ( 192*5 j , p* 135* exposed at /inona and enterprise are parts of ids same formation and be dropped tbs term enterprise because it was preoccupied* Cooks and most later workers have considered tbe inona to include ail of the beds above tbe Basic member and below tbe Eilpha shale* m this report the tern Ninons, ie restricted to those green sands to which tbe name was originally applied and the underlying sands are included in the Neshoba*

if.ost authors have considered the vinona green sand to be a member of either the Tallahatta or 14.ebon formations. It ie raised to forst&tionai rank in this report because it is a very distinctive

lithe logical unit which has a wide areal distribution» it being the only formation in tbe Claiborne group which extends all the way across tbe state without extensive facies changes*

Lithelogy • The Winona formation i s composed of groeneande and glauconitic sands which vary from light greenish gray to dark green when freeh and which weather to a distinctive dark, brick red color* The glauconite content of the Winona sande ranges from IQ to 9 G£* There ie a noticeable tendency for the glauconite grains to be coarser than the quarts grains and the sands are usually poorly sorted. These greet;sands and glauconitic sands are unusually coarse grained for sands of this type, although the median grain sire is rarely larger than medium ©and else* The ©tructure of the sand© i© commonly &aagive to poorly bedded and occasionally tfaic-beddad and even-bedded* high angle cross-bedding occur© rarely* In eastern ise is e ip p i the inona becomes len ticu lar and thin and lenses of ton-glauccnitic, massive to highly cress-bedded 26

sand occur in the formation at a few localities* quarta pebble© are

common Is the greensande in that area# Clay occur & in the 'rinona

sands as formless inclusions and there are a few exposures where thin lessee of black, carbonaceous shale occur in the section* The

vicuna sands are locally calcareous and fossiliferous lenses are common,

but surface localities where fresh fossils can be collected are rare#

Siderite occurs in the .inona as thin beds outcropping as

ledges and as isolated concretionary masses of dense# light brownish

gray material, but it Is rarely seen in the fresh state on the surface

because it weathers readily to limonitic ciaystone or ironstone* It

is particularly abundant near the top of the formation in the northern

part cf the aroa and its first appearance in well samples can usually

be taken as the top of the v inona* This fact is of particular value in the interpretation of old water well legs where eiderite is logged

as "rock*’*

The deeply weathered inena outcrop is marked by an abundance

of concretionary limonitic sandstone bodies which exhibit ail shapes

and sizes and degrees of induration* Ifeey are very useful indicators

for the weathered outcrop and for both the upper and lower contacts*

The upper contact lies immediately above the uppermost concretionary

ledge and the basal contact ie usually not far below the lowermost

concretionary material*

ower Contact • Th© Vincna-Tallah&tta contact is conformable

and sharply defined* The details of the contact differ somewhat

with the nature of the underlying material* The contact between th©

inona greensana and the Basic eiayeton© in eastern Tiesiseippi ie 27

slightly irregular and there is a heterogeneous mixing oi the two

facies at the contact proper* hut the uniform thickness ana persis­

tence c£ the uppermost basis beds in individual exposures disproves any significant truncation of basic materials* Borings and pockets

filied with material from above extend a lew Inches down into the

underlying beds* Several authors have considered this contact to be

us conformable or aisconfo ratable upon this evidence» but such contacts are common between the different beds in many marine sequences and

they apparently have little significance* At least seven such breaks

occur in 140 fe e t of f a irly homogeneous Lisbon sandy m arl in th©

k i t t l e stave Creek section near Jackson* Clarke County* Alabama.

The homogeneity of this section preclude© the existence of seven

large deposition©I breaks during ^isbon time and the contact® must

represent minor breaks in sedimentation*or diastems in which sub*

marine erosion was active* in the area where the Winona groeneand overlies the Neshoba

sand the contact sho&e more variation* At some exposure© the two facies are intimately mixed through two or three feet of section and small lenses of glauconitic material are found several feet below

the main body of the greensand* The glauconite ie abundant and ir­

regularly distributed at and immediately below the contact and be*

comes increasingly rare downward* there is no reason to believe that this contact does not represent the same set of conditions as

the '"inona-Baeic contact in eastern ::;i»eiseippi* The difference® in

the details are probably due to the comparatively unconsolidated nature of the i.eehoba sand as compared with the Sasic clays* At

ether outcrops the transition from inona to fteshoha facies ie uniformly gradational through several foot of transition bode# This type of contact apparently represents a gradual* uniform change in th© type of material being deposited*

Thickness ■* The thickness of the inona groeneand varies from 0 to 50 feet* Over most of th© area mapped At i s co nsistently about 25 feet and variations of over 10 feet from that figure are rare* Th© formation ie thin and poorly developed in Clarks and

Lauderdale counties* ranging in thieknees from 0 to 20 feet and averaging about 10 feet* The few places where it is absent seem to be oases of simple non-deposition of the iaciee* The maximum development of the imma greensand occurs in the general vicinity of the type locality*

osoils - The TAnona greensand contains two excellent index fossils* They are Qrfcrea sellasformle mr« ii.sbonene.ie ana Tro- gcute 1 la migsisgloaleneia* The formation has a rather large and varlea fauna which includes pelecypo&s, gastropods* echinoids* crabs* shark's teeth* foraminifere and ostracode* but there are very few localities in the state here fresh material can be col­

lected* • h© best localities are in and around th© town of .Inter- prise* Clark? county* osier {13} lists 42-specie© of maarofosgiis identified by Co oka from several localities in this vicinity* I he microfauna of the inona has not been studied in detail*

D istrib u tio n - See D istrib ution of th© /.Alpha on page 35*

Tooogranhie expression - The Tinuna groeneand has little or no topographic expression in eastern riieelssippi whore it overlies

{13) V* M. Foster* op* g i t ** pp* 62*64* ill© Susie because it i® poorly developed and its influence is over- shadowed by that of th® Basic clay stone# X» th© central part of th® area sapped th® inona forme a secondary cuesta lying to th® west of th© stronger Bahrston© Cuesta, bat northwestward along th© strike the cuesta developed on the Winona becomes more Marked as the Bahrstone

Cueeta grows weaker and in the northern part of the area the inona cueeta is the dominant topographic feature*

Soils * The Winona groeneand gives rise to a very distinctive

light brown to gray sandy loam soil of considerable fertility# The top-soil ie thin* ranging up to © inches in thickness, while the

eubvseii is from 16 to £4 inches in thickness and ie a red to reddish

brown, friable sandy clay which usually contains fragments of sand­

stone concretions* This s o il ie known as the Macogdochee or some closely allied series*

DepositionsI Conditions - The oysters, eohineid® and crabs present as fossils in the Winona groeneand indicate a shallow*water, near-*shore environment for its deposition* Buch an environment would have currents capable of handling such coarse-grained material* Winona deposition represented an epoch of eballow-water conditions which closed the cycle of marine deposition initiated by th© advance of the T&ilah&tta sea* SILPH& SHal®

introduction * The tern £Alpha first appeared in print in th© guidebook for th© Claiborne and ileex Field Trip of the Miseis-sippi

Geo logical Society (March# IMu)* The original definition appear© on page 3* It Ass **A workable bed ©f gray white and chocolate brown clay# having a thickness of about 60 feet# was found to 11© between the inona and the Kosciusko in berth Central TiasAerlppi in Carroll# Grenada# and ^ttaia Counties* * r* Raymond Moore# formerly with the Arkansas Fuel Oil Company# found this to be a good key horixon# and suggested the name of zilpba# from Zilpfca iUver in a tta in County*^

although term hau never been formally defined, by it© author# the conditions are such that there can be little confusion regarding the beds to ohieh it was first applied* The name &iipha is in common use in kiesleeippi at the present time and is used in this report as a© fine a in the guidebook* Th© A i Ip ha shale doe© not outcrop on 2ilpha creek (or River; proper# but thee© bed© reach their maximum development in that general area* -he best exposure of the shale in th© vicinity of Zilpha Creek is found along the county road at ducksnort Hill and that locality is herein set up as th© type locality of th© zilpha shale in order to avoia any confusion in tne future* The type section is described under ^ithelogy* tfte Zilpba shale is faAven fo matronal rank in this report becauses

L* it is & distinctive 11thological unit which can be traced without serious interruption across the state of h.issiesippi*

Z* diving i t the rank of a taember along with the inona or

Kosciusko would necessitate th© introduction of a new formational name# sine© both of those terms are restricted to otner beds and 31 should not ho expanded to include tho Li Ipha section*

Litbolo&y - fh® characteristic ilthology of th© ZiIp ha shale may bo e©®® at th© exposure herein eelooted as th© type locality which ie along the county road at Bucksnort Hill, one and a half miles ntrth of zilpha Creek and near th® center of section @/TL 6N/B6SE» extreme northwestern Attala County, ^ieaiesippi* The section her© ioi

ZILPHa SHABS - upper contact not exposed

29* carbonaceous shale - chocolate brown to light gray to dark red*

abundant partings of light gray silt and many pocket®, stringers

and interbede of highly glauconitic material occur to within

4 feet of the tap} few thin stringers of soft, whit©} giau«* eonitie ti listen©} plant fragments common in the chocolate

mat©rial$ grading down into

22^* carbonaceous shale - similar to above but non-glauccniticj

upper 14* badly weathered and slumped} grading down in to

2^-' glauconitic sandy clay * chocolate to light gray; glauconite

ana quarts sand concentrated in pockets and stringers near

base and becoming rare toward tcp; few thin, irregular

concretionary ledges of limonitic clayetone 5 scattered molds

of fossil©} this bed is really the transition section between

typical Zi ip ha and Inotta facies

Contact conformable

54* Total thickness of iIpha exposed

•/IWOSA GRSShSAMD

4 * heavy concretionary ledge of limonitio sandstone developed on we&iherea greeneand} meet prominent bed in section 32

1 0 * fcesiliferoue greeneand * light greenish gray to yellow-brown

to dark* briok red; massive t© irregularly bedded; foeeila

abundant as laclcls eoncentr&ted in email lenses; upper 4 to

8 feet of this section very it'regularly indurated; disoriented

pellets* tubes ana inclusions of gray clay common; much of

glauconite of coarse eand sire; grading down into

5* glauconitic sand or groeneand - similar to above but loss

glauconitic and less iossilifarcus

carbonaceous clay - ohogo late to gray; sandy and honeycombed with sand-filled boring® and pockets; pinches out in cut

6j* glauconitic sand or groeneand - light greenish gray to yellow-brown

and red; upper half thin-bedded and banded; lower half contains

as abundance of disoriented pellets and filled tubes of gray

clay; beds i-regularly stained black by manganese ©xide(l)

35* Total thickness of inona exposed

Base of section at £loodplain level of Big Black River ~

Elevation 285 (altimeter)

Total section exposed - 80*

■ i& indicated by the described section* th© £ilpb& formation ie composed chiefly of carbonaceous shale and clay* hen fresh* th is material is black, but it is readily oxidized to a chocolate brown or gray color and is usually seen on the surface in that condition*

It ultimately weathers to a dark, brick red clay. *lhe lower part of the eeetien is typically a nearly-pure, blocky clay, while the upper portion ie much more silty and shaly. artinge, stringers and lenses of micaceous eiii and sand, many of which exhibit high angle cross-bed- ding, are the most common associate® of the oboco late shales# .; lent fragments are found through®at the section, but tend to be much more abundant in the upper, shaiy facies#

The lew®most few feet of the :iipfaa are glauconitic and sandy, thee® tw® material® being abundant and irregularly distributed near the baaal contact and becoming increasingly rare above* Glau- conite ale® occurs in small lenses and pockete which are found all the way to the top of the formation* In northwestern ttala County where the Cilpha reaches it® maximum development, th® shales of the upper part of th® section are often highly glauconitic* several glauconitic bed® can be recognised at some outcrop® in that area*

Throughout the southeastern part of the ziipba outcrop there i® a diecontinuous groeneand bed at the top of the formation* it is a dark greenish gray, fine grained, argillaceous, lignitic groeneand which i® sparingly foeei liferoue at a few localities# It reach®® a maximum thickness of 15 feet in th® area west of Union, Newton County#

This greensand ie separated from th® overlying basal Kosciusko sand by a few fe e t &i sparingly g lau conitic tilt* in southern Neshoba

County there are several lenses of glauconitic sand and greensand

which lie from 20 to 30 feet above the main body of the lilpha*

Thee® lenses were sapped as part of the kilpba in order to include as much marine material as possible in that formation rather than In the nen*>marin& Kosciusko formation#

601&& of the concretions formed in the zilpim are very useful in identifying the deeply weathered outcrop* -y far the most abuna&nt type found is a soft, flaky, yellow-brown Umonitic siItston® which ie formed along the eilty partings of the shale by the deposition of 34 iron oxide from circulating groundwater• a similar typo of claystone often form® as lodges of dense, hard material at th© top of the shale section. la the northern and southeastern parts of th© area mapped these ledges are strong and persistent and serve a© good markers for the top of the formation*

Throughout north-central Attala County, where th© z i ipha is best developed, rounded, yellow-brown limcmitic elayatone or ironstone concretions are commonly found* These concretions are hollow or spongy in the interior and have a characteristic shelly or concentric structure* They occur at definite horizons as weak ledge® and are derived from weathered siderite*

Lower Contact - The 2ilpba- iaona contact Is conformable and sharply defined* The material at the contact proper 1 © a heteroge- bogus mixture of carbonaceous clay, glauconite and quarts sand* Below this taerison the clay diminishes and disappear®, while above it the glauconite and quarts sand gradually do likewise* The actual tran­ sition from one facie® to the other occurs within ^ to 3 feet of section except in a few places in .tta la County where the two fa c ie s are fauna interbedded at the contact* The litbo logy of the overlying and underlying beds and the sharpness of the contact Indicate that this contact represents a rapid change from shallow marine to marsh

conditions* The heterogeneity of the material at the contact was probably caused by wave agitation during the change of conditions*

This contact is the sharpest and most reliable one In the Claiborne section in Mississippi and it is the only one which persists across the state without extensive facies changes* Lor these reasons i t was used as the datum plane upon which i la te % was constructed* 35

Thickness - The thickness of the Zi ipha shale ranges fromQ to

?5 feet in Mississippi and varies widely over short distances as shown on I late 2* The formation ie thin and absent at a few localities in

Clarke and Lauderdale counties* averaging about IS feet and ranging up to 35 fe e t in thieknees in th a t area* I t becomes th ic k er through the central part of its outcrop* averaging about 25 feet and ranging ficm C to dQ feet and being absent at a few localities in eastern

Leake County* The maximum development is reached in Attala and Holmes

Counties where the average thickness is aoout 40 feet and the maximum

of 15 feet ie attained* North of that area the average thickness

decreases to about 15 feet and there are numerous localities where

the formation is thin to absent*

Hog si Is - In places where the Zilpha overlies ioesi lii'erous

Winona material* the basal few feet of the shale usually contain fossil molds* but fresh fossils are very rare in the formation* Both

Oat£ea aallaefpraie n r . llsbgassgAs U 1 t roe cut glia mlg g jjsip p ten Ble occur is this basal part of the formation* Neither the macrofauna nor the microfauna of the ZiIp ha have been studied in detail*

listributton » Th© small scale of the geological map precludes showing bets the Zilpha and Linona outcrop belts and so they are com­ bined* The relative areal distribution of the two formations can be obtained by a study of Figure® 1 and 2 together* The outcrop of the

Zilpha and incna formations in eastern Mississippi i© a thin and very irregular belt which follows the Tallahatta outcrop closely and has but a few topographic outliers and inliers* In the central part of the area this belt expands to an average width of about two miles ana its 36 irregularity and the numerous topographic outliers reflect the etrengih of the inona Cuaata* Jm northeastern C a rro ll, northern Montgomery aad

Grenada Counties the outcrop ie an irregular holt averaging about half a mile in width and having several topographic outlier# and 2ntiers#

■i$Jk9SF9V.W* aypreaBiPE - xb« Hi ipha shale has a weak top©— graphic expression# The outcrop is usually marked by a topographic

flat or beach which ie often of considerable aid ie mapping operations#

^oil© - The Zilpha shale gives rise to a gray or brownish gray,

very fine candy loam coil# The top-soil ranges up to 6 inches in

thickness and the sub-soil is of from 14 to £Q inches of brown to

red, heavy, plastic silty clay or clay# The sub-soil is usually

underlain by a mottled gray and red, heavy, plastic clay and in

places the top-soil rests directly upon this material# These coils are known as the Boswell Oi buaquehanna or some closely allied series*

They are distinctive and of considerable help in mapping, brut are

generally regarded as poor agricultural soils*

^o eitio aal Conditions - The nature of th© overlying and

underlying materials indicates that the Z iipha shale was deposited

curing a time of change from marine to hen-marin© conditions* The

formation has the characteristic;- of both types of deposits# its lithe logy suggests that, following the deposition of the inona, th©

shore line refloated in th© lac© of accelerated non-marine sedimenta­ tion* Tbe first indication of a change in conditions is the appear­ ance of ©lay which was apparently deposited in very shallow water where wave action mixed i t thoroughly with th© underlying greensande* r»e the shore Ain© retreated farther seaward, this clay was covered by silty clays, silts and sands depoeltea on the tidal flats and in the coastal marsh* The high angle cress-bedding in the silt lute rhea a in the upper* a hoi; portion el the z i ip ha indicates depoei tion&l con-* ciitione in which current a played an important part* The probable site ox deposition of this mat ©rial was in lake© and bays in the coastal marsh where the wavesand bettor current © winnowed the sills? out of the mar eh deposits*

The greens&nd bed at the top of the &ilph& in eastern alee- iesippi, the glauconitic eand lenses above the main body of the bilpha in southern Neshoba County and the several glauconitic beds in the formation in attain County were all apparently deposited during local, miner advances of the sea*

The contact relationships indicate that the absence of the

bilpha. shale at & few localities in the state is due to simple non-deposition of the facies rather than urecnform&fol© overlap*

The thinness of the lower transition facies* rarity of a

repetition of facies at the contact and the general thinness of the blipha section across the state indicate that the change from marine to non-marine conditions occurred rapidly over a wide area* 38

f 0 SCI OS KG FORMATION

Introduction - tbe tern Kosciusko me proposed by Cook® (14) to replace Lowe*s ter® °Decatur«* which me preoccupied* Cooke*e original definition of the Kosciusko is*

“The same Kosciusko sandstone member ie here proposed as a designation for the le&gea of s&ceharoidal to quartet tic sandstone exposed in the vicinity of Kosciusko, the county seat of Attain County, Mississippi, and for the unconsolidated sands of the same age in Mississippi***

The beds specified by Cooke lie near the base of a thick section of non-marine sands and shales which cannot be satisfactorily subdivided and so the term Kosciusko is redefined in this report to include all beds above the Lilpha shale and below the autubbee form ation,

Most workers since Cooke have considered the Kosciusko to be a member of the Lisbon formation. It is herein raised to the rank of a formation because it ie a lithoiogic unit with definable upper and lower boundaries which has a wide areal distribution*

Lithe logy ~ The Kosciusko formation is a heterogeneous, highly lenticular, non-marine section in which sands and shales are the dominant facies* The baeal 50 to 200 feet of the formation is ty p ic a lly composed of massive to highly orose-bedaed sands which are colored red, brow*., yellow, purple, pink, violet, gray and white on the outcrop* This vivid coloration is a surface effect, since the sands are invariably light colored in well samples* These samples also show that some of the sands are sparingly lignitic. The sands are predominantly fine grained and fairly well sorted, but ex*

(14) C. yyths Cooke9 ojo. p it* , pp* 135-136* 3® hi bit ail variation® in grain else and degree of sorting. The in­ dividual grains are usually coated with a thin film of iron oxide.

Clay occurs in the ©and as pellets, halls, irregular inclu­ sions, partings and stringers* In a few places these inclusion® become abundant enough to form elay-b&li conglomerates* The clay is a light gray, sandy or silty material which becomes mottled pink or purple when slightly weathered*

Shales increase in abundance above the basal sand until they usually predominate over the sand in the upper part of the section*

There are three types of shale in the Kosciusko* The light gray to mottled purple and gray, silty clay which is found as stringer® and pellet© in the sands also occur as lenses of shale distributed throughout the formation. Black to chocolate brown, carbonaceous shales identical to the carbonaceous shales of the Mlphn and other

Claiborne formations are common as lenses in the Koeciusko throughout the central and western part of its outcrop. The third typo is a dark gray to greenish gray fresh) to light gray or brownish gray

(weathered), iignitic, silty shale which grades into the carbonaceous shales on one hard and into argillaceous silts on the other. These silty shales vary in structure fro ® even-bedded and laminated to highly cross-bedded* I lent fragments are abundant and well preserved fossil leaves are found at a few localities. leathered remains of siaerile concretion® up to one foot largest diameter are quite common*

These shales are particularly abundant in the Kosciusko in Carroll

County and are well exposed along the highway between Tinona and

Carrollton*

The ledges of quartsitic sandstone mentioned by Cooke in 40 h is o rig in a l a e iin itro n of the Koeeiuek© are the most d is tin c tiv e feature of ths formation* They airs light gray, siliceous* coarse si Itstones which form by surface induration from light gray* compact* argillaceous silt lenses in the massive Kosciusko sands and which appear on the outcrop as quarts!tic boulders and ledges* They are best developed in attain and Holmes Counties where they form di^con­ tinuous ledges which occupy a etratigraphtc horisen SO to 7& fee t above the top of the Zilpha* They alee occur in Grenada* Carroll,

Me&ke and denhoba Counties, but they are only locally developed in those counties* Meet of the older authors mistook these ledges in

Attala and Holmes Counties for iallabatta material and considered the Claiborne section below them to be of lallahatta age* Cooke

(IS) was first to recognize their true stratigramhie position*

ietrified wood and lignite are very rare in the Kosciusko fo relation which sometimes serves to differentiate the formation from

ilccjt and Cockfieia beds* a lee, the sands of the Kosciusko are ra re ly micaceous, a fa c t which helps to d iffe re n tia te them from ths lower Claiborne sands*

imonitic sandstone, si Itstone and claystone are the common concretionary materials occurring in the Kosciusko* each has its characteristic lithelegy and place of occurrence* -11 are produced by the deposition of limonite by circulating ground-water and are surface phenomena* ^imonitic sandstone forma as irregular ledges or inclusions in the iron-stained sands* It occasionally has a fluted or tubular structure* it varies from yellow-brown and sorae-

( IS) ib id .* f F* 1 3 b* 41 what indurated to dark brawn and vary hard* Lomelimes these bodies fo ra on top of slay stringers where ground-water circulation ha® been impeded* Elsewhere they form is massive sands where there is no apparent reason for their location* This roaterial ie abundant throughout the Kosciusko and ail similar sands in the Claiborne in

• iseissippi. Tisaenitie si listens occurs as flaky» yellow-brown con­

cretions which form along the silty partings in the shales of the

Kosciusko and ehaly facies of other formations* Limoni tic c lay e tone ie the least abundant of the three types# It occurs rarely at the top of chocolate brown shale lenees in the formation* The eid©rite

concretions in the silty shales weather to shelly or concentric-struc­ tured liraonitie claystone or ironstone bodies*

-ower contact - The £©seiueko-£il|ha contact is conformable and gradational* The gradation occurs from the basal Kosciusko sand

through an interbedded sand and shale section into the typical Zilpha

shale* The thickness of the transition section varies from a few

inches to 30 feet and often change e quite markedly over short dis­

tances* In eastern Mississippi where the top of the Tiipha is marked

by a greensand bed the transition takes place through a thin section

of sparingly glauconitic silt ana a similar situation exist® in the few places where the yoeciusfco lies directly upon the inona greensand.

Thickness - The thickness of the Kosciusko formation gradually increases northwestward along the strike from &5 feet at the .labama

line to a maximum of 400 feet in Attala* Holmes and Carroll Counties*

The thicknesses In the eastern part of the state were measured directly

©n the outcrop* thoe© lu the central part are derived from profiles* and those in the western part abiKupon projections of surface /"v B UEittftfW 4£

dips combined with water and oil well data*

Foegile » fossil leaves are found in the silty shales in

C arroll County* The f lo ra has not been studied#

Distribution - in eastern Clarke County the Kosciusko outcrop

forma an irregular belt averaging about 6 miles In width* Northwest*

ward across the state this belt increases in width to a maximum of

20 stiles in attain and Holmes Counties* Details of the distribution

of the formation are shewn on Flats 1.

Topographic Sxoroseion * the basal sands ef the Kosciusko

support a comparatively rugged sand hills topography* In eastern

Mississippi this sand hills topography is superimposed upon the

gentle slope of the Suhrstens Cuesta and throughout the remainder

of the area mapped i t ie superimposed upon the gentle slope of the

cuesta developed on the Winona* in the areas where the 2;ilpha

formation is well developed these sands form an escarpment over­

looking the topographic flat developed on the outcrop of the shale*

The average local relief in the sand hills is about 7S feet, while

the maximum ie about 15'- feet* The upper, more ehaiy portion of

the formation supports a more rolling type of topography in which

the local relief averages about 50 feet*

The quartsitic si Itstone ledges in the osciusko in Attala

and Holmes counties exert a strong influence upon the topography*

They support a bold escarpment along which the most rugged tepog*

rap by in the Kosciueko outcrop belt ie found*

coils - The sands of the Kosciusko give rise to fine candy

loam and fin© eand soils known as Boston, Greenville* Orangeburg 43 or Nerfolk or some closely allied series* They have been described under the soils of the Leshoba sand os page 2 £«

The sand and shale sections of the * ceciueko give rise to a similar fine sandy loam which has more clay in the eub-eoil. This is the Shubuta fine sandy loam or some closely allied type*

in eastern <*ttala» eastern Leake and southwestern Neshoba

Geunties the sandy soils of the Kosciusko contain abnormal quantifies of silt and grade into silty loam soils* This silt is residual from a thin blanket of brown silt which once covered the area* in the area bordering the ^eese hi lie region on the west the Kosciusko is covered by a mantle of brown silt which gives rise to silt loam soils*

bspesitional C.nditfoae - Many features indicate that the

Kosciusko is a non-marine deposit* Its heterogeneity ana lentia- ul&rity and the lignitic nature of its finer grained materials all point to this conclusion* It lacks the marine fossils, glauconite and lime sc characteristic of marine ertiary deposits* The exten­

sive croes-beading of its sands and silty shales and the presence of clay-bail conglomerates and local eroeional channels in the sands indicate a stream-laid origin* its rather consistent thickness over a wide area precludes a flood plain site of deposition* 11 of these

facte indicate that the formation was laid down on the coastal or d e lta ic plain by a number of small streams* The presence of an abundance of >:.i Ip ha-type carbonaceous shale lenses through the section

indicates conditions not greatly different from the marshy conditions at or near sea-level under which the Zilpha was deposited* inly along a subsiding coast line could as much as 400 feet of such near-sea-level materials be deposited* 44

The iithoiogy of th© ^oeciusko suggest© th at, fcimowing the

deposition of th© z i lpha> tbe coastal marsh was flooded by stream-born©

sands while the finer grained material© were carried farther out and

deposited in the coastal marsh or incorporated is the marine deposit©*

The general thinness of the transition faoise between the ^ilpha and iosciuekc formation© indicates that this change occurred rapidly*

juring middle *ad upper Kosciusko time the gradient© of the streams

on the deltaic plain were diminished and much of the finer grained material sas cropped on the coastal plain where it now appears as

silts and shales*

There is l it t le positive evidence regarding the condition®

Uf: .er which the quartsitie si listen©© of the Kosciusko were deposited*

They are derived from lease® of silt which are overlain and underlain

by fine-grainea, non-marine sands* mifhough the ledge© are discon­

tinuous, their main envelopment occur® at about the same stratigraphic

horizon. The facts that they arise from a distinctive type of compact

silt and that the overlying and underlying material® are not siliclfied

suggest th&t the siliceous cement may b© primary* h possible ©it© of

deposition for these beds ie in ire©h-#at©r lake® on the ueltaic

plain in which email quantities of opal were being precipitated* 45

■aUTUBBEE FOBMAEtGN

m s s M & U m Th» tens .autubb.a w*a introduced by toaa in 19 IS (16)! tba name being taken tr a m Tautucbee btation on the southern Haiiroad in northwestern Clarke county* The original definition let

11 The autubbee Lari® constitute the m et extensive division of the Lisbon, since other member* of the formation have unimportant outcrops* ‘he Vautubbee beds are all marine, consisting of highly calcareous and fossiiiferous marl©, of gray to almost white color, or of darker bluish and greenish tints, due to the presence of glau­ conite. in tbs vicinity of liewten and a few other localities these marie pass vertically into clays or sands which are often lignitic and foseiliferous* The Wautubbee marls are locally rich in marine fossils, ex­ hibiting a very characteristic fauna* The large aaadie—sn&pea oyster, oetrea eellaeformie, is especially abundant* ineee beds in southeast Mississippi have a thickness of about lUo feet, and dip southward at a rate of £3 to 2b feet to the mile* The thickness in west .. ieeiasippi is perhaps as groat, though not so evident***

ginee the term autubbee is satisfactorily defined and ie well eetabLishea in the literature, it is used in this report in preference t© "Lisbon", Lisbon marl” or "typical Lisbon** because, although the autubbee section includes beds which are lithe logically and faunally identical with the Lisbon formation at its type locality,

those beds constitute a minor part of the section which has been called

i.ieboE formation in nearly all of the later Mississippi report© and it would be confusing to restrict such u well established term*

,he term

> oeciueko and below the Cockfield in eastern and central iseieeippi

and its non-marine equivalent, the Lhipp’s Creek shale, in western

V16) 3* &* Lowe, "Mississippi, its Oeclogy, Geography, . ui le and Mineral resource©," Mige* Geo^* MiA* i i (1919), pp. 7b-76* 46

Mississippi* tbs upper contact is placed at tbs top of tbs carbonaceous shale section overlying th© marl© ({Jordon Creek shale member of this report) rather than at the top of the marls themselves because these shales exhibit many marine character!sties and logically belong in the marine section*

Tost workers in iesieaippi have considered the Tautubbee bode to be a member of the Lisbon formation* The ^autubbee is considered tc be a formation by the author because it can be subdivided into several lithologic units which are logically members and because it has a wide areal distribution*

^n eastern Mississippi the autubbee section is divisible into three distinctive and persistent lithologic units which are named and given the rank of members in this report* They are:

Gordon reek ©hale member (top) Fotterchitte member

vrchusa marl member ;bottom)

This subaivision becomes im practicable in central hewton

County and the formation i s mapped as u n d ifferen tiated autubbee as far northwest as the Tockahockany Liver in northwestern ^eake County*

Beyoca that point the section become© highly lenticular and in south­ western -ittala county the marine material disappears* interfingering along the strike with non«*raarine beds* in western Holme© and Carroll

Counties there is a thick tongue of carbonaceous shale lying at the stratigraphic boriaen of the marine 'autubbee* it ie named the chipp*© Creek shale member in th is report and is considered to be the non-marine extension oi the Jautubbe© formation* -s shown on

} la te 2 * the autubbee contacts are a rb itr a r ily drawn across the gap 47 between th© rorfc fewest ermaoet exposure of th© marine >:autubbee and the type locality of the ohipp*e Creek shale*

iirobusa eJBEktt

introduction * The name Lrcbuea is taken from Lrcfcusa springe« a well-known locality and former health resort on the Chickasawhay u iv©r south of the town of ^uiimaa, Clarke county, ^ieeiteippi* The type locality of the member ie a bluff beneath the south end of the highway bridge and across the river from the springe* This member has the same lithe logy as the Lisbon formation at Lisbon ana Claiborne b luffs, ilabama* ..t constitutes the major part of Lowe's ‘?autubbe* marl and has been eallau "Calcareous Claiborne" by Hilgard and "Lisbon marl* and "ty p ical .Lisbon" by other authors*

~itho logy - Characteristic .*rehuea lit ho Logy ie well exposed at the locality selected as the type* which is a bluiC beneath the

south ana of the bridge across the Chiekaaawb&y .Tver on highway C* $*

45 two m iles south of ^uitman in the s z of :;j$ of section l4/T2H/r,153*

The section here starting one foot below road level at an elevation of ZZZ fa s t is i

ARCHIL’.'.-* ,.AKL it.SLbSii LF '^aUTUBB;5S £ OHMaTlCli — XKJPiS BSCTILK

marl or soft limestone - light gray to white, fossi Uf ©roue,

sandy and glauconitic

3f * marl - light gray to white, fossiliferoue, eandy and sparingly

glauconitic* abuodam irregular ©lay ioelusions* lees indurated

than bed above* scattered weathered pyritifereue concretion®*

abundant ustrea eellaeformis and other fossil® in basal foot

ljj * limestone - light gray, sandy, glauconitic and ioeeiliferoue*

forms *ip of small f a lls 48

10&* am ti - similar to 3&* bed above* beiyea sellaefoarais and many other forme

1' oyster bed - dark green, medium-grained greeise&nd with an

abandonee of Octree se l laeformie and comminuted she He

8* marl - similar to XQ$* bed above

1* limestone - aiecontinuou© ledge of material similar to that above

and below but slightly more indurated

31* marl - similar to 1Q§' bed above

Base ox section - low water level of Chiekasawhay idver

46* Total thickness of measured section - neither contact exposed

In the area around GrandeIX in eastern Clarke County, the

rchuea becomes quite lenticular and contains bodies of nen-gl&ueoiaitie

sandy but elsewhere i t i s a p e rs is te n t, homogeneous unit* on the weathered outcrop the lime is leached from the sandy marls and the

residual material is a dark red, sparingly glauconitic sand with an abundance of irregular clay inclusions* hen deeply weathered, the marl closely resembles some of the weathered non-marine Claiborne

sands*

The basal few feet of the r.rehuea are typically xuere sandy than the remainder of the member* This part of the section ie a fine

to meaium grained, sparingly glauconitic, calcareous sand which is

relatively unfoeeiiiferoue. Xt bears the earns relationship to the

rchuaa as the pebble-bearing, glauconitic sana at the base of the

basic bears to that member* The uppermost few feet of th© marl con­

tain angular fragments and irregular inclusions of tan bentonite at a few lo c a litie s in Kewton County* 49

Bdwar Contact - Th® ./*r©teuea~Koeoiusko contact i s dis conformable and sharply defined* it closely resembles the Basie-Meridian contact in th© eastern Mississippi area and undoubtedly represents th© same sequence of events* The transition frma maria© to non-marine facies occurs withie a t to 3 foot section in which th© two facies are mixed in a heterogeneous fashion* The basal portion of th© Arcbusa contains small blocks and inclusions of material from th© beds bo low and small lenses and pockets of marl are found in the uppermost few feet of the

Kosciusko* Marl-filied borings extend a foot ©r so down into th© non-marine beds and -liegeminated glaucon.it© is sometimes found as much a© Xu feet below the contact* The uppermost i ©eciusk© bade upon which the rehusa rests change lithology over short distances along th© strike from sands to carbonaceous shales to lignitic, gilty shales#

This ie the condition which would logically be expected after trun­ cation of the uppermost beds of the deltaic pl&i*i by wave-erosion along an advancing shore Line*

Ids contact is & reliable mapping horison., but in often dif­ ficult to identify on the deeply weathered outcrop*

Thickneae - The Arefcuea maintains a thickness of 4£ to 60 feet in lark©) Jasper and southeast err Kowton Counties. It Lens©© out in central Maw too County, but reappears ®c a 15 foot lens in northeastern cett and northwestern bewton Counties.

TosalIs * The drohusa marl constitute© part of the Octree eeljLaeformis sone of ieaiasippi# It also contain© a large fauna very closely related to that of the miudle and upper Id ebon at Lis­ bon and Ci&iboifle B lu ffs, Alabama* to

i et-teretene iffikyr introduction * the Potter©hitto member ie named for an outcrop sear lotterchitto Creek in ©outh-central Newton County, ;..i©siaeippi*

The type ©action ie exposed in a eeries of road cut© along the

-©wtcn-^Qc&tur highway (state Highway 15) on th© south valley wall oi the creek about 2 mile© northeast of the town of Newton and in the

J*£ of 26 and ss of ©f £3/T6K/Ril£ (see profile c,* The member i©

litho logically the most heterogeneous of the three member© of the

autubbee formation of eastern -iesissippi, but certain feature© make i t one of the moot easily id e n tifie d on the weathered outorbp*

^itholoay * Characteristic litho logy of the i Otterchitto member is well exposed at the type locality* starting at road level at th© top of a hill o*o mile© northeast of the Junction of highway©

U* b* and state 15 at an elevation of 425, the section exposed ie*

GOCttfISajj./ - Wuw-vTiQh

12 * ©and with shale intercede - ©and red and red-brown* ©hale gray

Contact conformable and irregularly ©lumped

AUltfBBSS fOni&illti.N

GilSiSk GHitiiS -siSMBiSH

12* carbonaceous anal© to biocky clay - chocolate brown to light

yellowish gray to redj basal 2* eandy and glauconitic and

heterogeneous| 2* above base i© a thin ledge of whit©, spar­

ingly glauconitic, siliceous ©iitetone which is a typical

feaxure of the member in this area

contact conformable

FCTlIiHCHiTXG tiJaiblSn - T¥r & ixfiiC'JTXUAl

6* glauconitic sand - dark greenish gray to light greenish gray to red* argillaceous and lignitic* i foot below top of tbi© bod

ie & weakly developed concretionary ledge with mold© of fossil©*

ted locally inaurated into soft, whit©, eiliseoue sandstone

concretionary bodies of irregular shape* basal & feet contain

abundant molds of fossils clay - chocolate brown* sandy and glauconitic* heterogeneous 9

many molds of fossils greensand - light greenish gray to brown* argillaceous* abundant

molds of fossils* near top are many irregular, cor*centri^struc­

tured limuniiic claystone or ironstone concretions* came of

which contain a core of light brownish gray siderite* 4 fe e t

below top ie an oyster bed which contains an abundance of

ig tre a g e llae fo raie and many other forme

Base of exposed section hissing eeetiea section continued starting at top of out immediately south of

t o tte rc h itto Greek bridge glauconitic sand - light greenish gray to brown* argillaceous*

few mcide of fosuite* really a deeply weathered sandy marl or

calcareous sand clay * medium gray* blecky and iignitic* grading down into clay * light greenish gray* sandy and glauconitic* heterogeneous*

sparingly £ossiliferoue* scattered weathered siderite concre­

tions near center glauconitic ©and - light greenish gray to yellow* very fine

grained* calcareous and very fossiliferoue with istrea eellae-

forrolg and many other forms* abundant small calcareous ©oner©- lio n s

3^* oyster bed * greenMU&d loaded with Cetrea ©yljtyeferftiq and many

ether forma? light greenish gray t© y©liow-brown$ loos® to

slightly indurated? most prominent bed in section

5* glauconitic sand or greensand * light greenish gray t©

yellow-brown? banded appearance? brown bands are indurated

and contain earthy slderite? few thin stringers of foseilif-

eroue greeneand? six inch, dark green, medium grained, foe*

silifercus greensand stringer one foot above base

36* Total thickness of lotterchitto member

Contact conformable

a RCHBSA MARL klB IK

16^* sandy marl - medium greenish blue to gray and yellow-gray? argillaceous, sparingly glauconitic and highly fossilifer one?

lens with abundant Octree gellaeforiaia near middle? two dis­

continuous 6 to 8 inch ledges of whit© to lig h t gray, sandy

limestone near base? about 3 feet below top ie a bentonitic

section in which irregular inclusions of bentonite and ben­

tonitic clay occur in a matrix of fessilif©roue marl

Base of section at road level at base of cut - elevation 359*

Total autubfcae section measured - 66£ *

Total section measured - 78^*

nearly complete lotterchitto section similar to the type section ie exposed in a cut on the county road on the south side of

£ otterchitto Creek 3/8the of a mile west of the type locality and in the HZ of 3^ of &3/T6K/RHB* The section there ie less fosaiifferou© and the thicknesses and sequence 01 oeds are slig h tly d iffe re n t. The 53

total thickness as measured by hand level is 36 feet# This section may he considered, an alternative type section in ease th® other on®

ie destroyed#

-vs shown in the described section# there ie considerable

variation in the lit he logy of the iotterchitte* Ail gradations from

greensand to non-glauconitic eana are Pound* These sands vary from

calcareous and marly to non-calcareous and from highly fossiliferous

to nen-fossilifereus* They contain pellets, partings# interbede and

lenses of carbonaceous clay and shale* Bom© of the clay inclusions are tubular and filled with matrix material* ifae different materials

are usually isterbedded and poorly bedded* occasionally they are

even-redded ana thin-bedded and# in rare instances# they are

cross-bedded* one of the individual beds can be traced any distance along the strike* The glauconite of the i ottorchitto is both light and dark green in color and is much finer grained than the inona glauconite*

Bentonite and bentonitic clay similar in appearance and occur­

rence to the bentonite in the ..rchuea, are found in the iotterchiiio a t a few lo c a litie s* :arthy s id e rite is common In th® member* hen

fresh* it ie a light brownish gray color and contains considerable

clay* but it weathers so readily that th® unaltered material is rarely

seen on the outcrop*

.he weathered lottercbitto outcrop is always marked by weak

concretionary ledges most of which are of brown# limonitie sandstone

developed on the weathered greeny.no. and glauconitic sana beds* Ihey

resemble rh© concretionary bodies in the vlnonu* but are never eo well

developed* . ome of the ledges are of brown llracmitic clay ©ton® or 54 ironstone derived from weathered eiderite* The concretionary bodies often contain melds of fossils and weathered grains of glauconite*

These concretions greatly aiu in identifying the TOtterchitt© on the deeply weathered outcrop*

Lower Contact * The 1 ©tierchitto-iirchufira contact is conform** able and gradational* In mapping this member it was found meat satis­ factory to arbitrarily include &e much as possible of the x-otierchii- to-type material in that member even if this procedure involved placing

lenses of Archusa-typ© marl in the 1otterchifto* The position of the contact at the iotterchitto type locality was established on that baeie* The thickness relationships chow that the type iotterchitto section is at least in part contemporaneous with the upper .rebusa in Jasper and Clarke Counties (see Plate 2)*

This contact represents a change of conditions similar to that represented by the iaen&-basic contact in eastern Mississippi* Thickness - The thickness of the x o tte rc h itto member rang®a between i£ ana 30 feet in Clarke, Jasper and southeastern kewton

Counties* It reaches a maximum of 36 feet at the type locality and becomes lenticular and loses ite identity in northwestern Newton

County*

Foeeiis * The index fossil Getreft eellaeforeaia ranges through­ out the otterchitto member* In addition* the letterchitt© contains a large fauna which is closely related to that of the iirehusa* but

localities where fresh fossils can be collected are rare* The type

locality is the best fossil locality for this member as well as one of the beat autubbee localities in the state* &>**#» smfe SMla saa£s£ Introduction * The name Gordon Creek is taken from a small creek which flows through .autubbee station and which ie crossed by the iaurei-Meridi&n highway (U* S# 11} a short distance south of that

station* The type section is designated m® that shown on the profile along the highway (see Profile B}* All of the important features of the lithe logy of the member are well exposed along this highway#

^itteo logy - The Gordon Creek member has th© same l i t ho logy and stratigraphic relationships as the iipha shale# It is predomi­ nant ly a carbonaceous shale which varies in color from black to

chocolate brown to gray to red, depending upon the stage of weath­ ering# Glauconite and quarts sand are abundant and irregularly dis­ tributed in the basal few feet and small pockets and lenses of that material are occasionally found well up in th© section# The lower portion is characteristically a nearly pure, biocky clay, while the upper part is more silty and ahaly# : l&nt fragments are found through­ out the section, but are more abundant in the upper, ehaly portion# Thin, irregular partings and interbeds of gray, lignitic, micaceous silt are abundant in the upper part of the section# This typical

litho logy is best expoeea on the type profile in a cut along the old

nigbway immediately east of the present highway location a t a point

l«o miles north of the highway overpass near autubbee sta tio n and again at the type locality of the , otterchitto member#

The second fac ies of the Gordon Creek exposed along the type profile is that of a dark greenish gray (fresh) to light gray (weath­ ered), lignitic, argillaceous, sparingly glauconitic silt or silty shale# ibis facies is well exposed in the cut beneath th© overpass near /autubbee Station and in cuts along the highway fo r several 56 miles south si* that point* It is a comparatively rare facies of the member*

thin beds of light gray to white» piaty, sparingly glauconitic,

siliceous silistens with a superficial resemblance to some of the Basic

siitstones are common 1® the Gordon Creek in Newton, Jasper and north* western Clarks Counties* The best development of these bods is found

in the area west of Decatur, Newton County, where a five foot section occurs at the top of the member* Dlsewhsre they occur as two or three thin beds near the base of the section*

six inch stringer of bentonite is found at the base of th e Gordon Greek in Jasper County and small q u a n titie s of light green bentonite or bentonitic clay are found at the same horizon at several

lo c a litie s in Clarke County*

ower Contact * The Gordon C reek^fetierehitto contact is con­ formable and sharply defined* It ie very similar in details to the

Zi lpha-zinona contact and represents the same sequence of events*

The material at the contact proper is a heterogeneous mixture of car­ bonaceous clay, glauconite and quarts sand* Downward from this horizon, the carbonaceous clay becomes increasingly ra re , while upward the

quartz sand and glauconite become rare and disappear*

This contact is a good one on which to do detailed field work*

It normally comes a foot or two above the uppermost concretionary material of the otterchitto and can readily he picked on the outcrop*

Thickness - In contrast to the wide variations in thickness of the ZiIpha, the ordon Creek member maintains © consistent thickness of between 15 and 25 feet throughout its extant* §7

* illgga genfeformis ranges up in to the basal few fee t ©f the Gordon Creek* Molde ©f f o s s ils occur occasionally in th e b a sa l, glauconitic portion of the member, but no lo c a litie s were found where fresh material could be collooted# Wo check has been made on these shales for microfossils.

L ndifferentiatad Wautubbee g>f Central. Mi.s^lesfppi

Introduction - The three-fold subdivision of the autubbee formation of eastern nissiseippi can be satisfactorily carried north­ west to Township 7 Worth, Kang© 11 Taet, c e n tra l wanton C©u*vty# Beyond that township the different facies become e© lenticular that satis­ factory subdivision of the section i© impractical and the formation is undiiferentiated# Ti.is undifferentiated marine sequence continues unbroken along the strike to the Yoekahockany Kiver in northwestern

^eake County# ioribw est of th a t riv e r the marine m aterials occur only as discontinuous lenses which lie near the same stratigraphic horizon and which can b® traced into the area around the village of

Tewport, soufnwestere .ttala Tounty without serious difficulty#

I orthweet of deweort the atratigraphi© equivalent of the marine

'autubbee is a highly lenticular section of non-marine sands and carbonaceous aha log*

-litholoigy - Th® Yautubbee of cen tral M ississippi ie composed of carbonaceous shales, feeeiliferous to non-fossiliferous greonsands and glauconitic sands, non-glauconitic sands and foseiliferous, sandy marls# The esotion is essentially a highly interleneed mass of the three eastern Mississippi fades of th© formation# The lower part i s usually composed of greensande, glauconitic sands ana m arls, while 58 the Upper portion is typically composed of carbonaceous shales, but in local areas the shales extend to the base of the section and in o th er places the sand© are found a t the top* Ja c e n tra l Leake County there are two 5 to 15 foot lenses of ehaly glauconitic ©and which lie well above the sain body of the vautubbee and are separated fro® it by non-marin© sands* Thee© lease© appear to be deposits which were laid down during local, minor advance© of the sea and they are inclu­ ded in th© L&utubfeee in order to keep all marine material© in that formation*

^ower Contact • The lower contact of the "/autubbee of central

Mississippi is ai 2conformable as far northwest as the Yoekahockany

Liver* Beyond that point the main advance of the autubbee sea was broken into several localised minor advances* lh© detail© of the contact in the area southeast of the river are very similar to th© aetails gi the .rchusa-Koeciueko contact in eastern &i©ei©eippi and th© contact forms a valuable mapping horizon which is often marked by weak concretionary ledges*

Thicknegs » The thickness of the autubbee section in north­ west era Lewton ana northeastern eott Counties ranges from 45 to 75 feet* northwestward along strike the thickness varies somewhat but gradually diminishes to 12 feet a t the Yoekahockany iver* Th© in - duelon of the two marine lenses lying above the main boay of th© formation increases the thickness to a maximum of 75 feet in central

Leake County* levaticne of the lenses of marine m aterial in the section northwest or the Yoekahockany River show th at they lie a t slightly different horiaone, the maximum vertisal difference between these horizons being about 40 feet* The !*autubbe© bed© ©f c e n tra l kiieeiasippi are

locally highly f®©silif©reus* but there are few localities in the area where satisfactory collecting is possible. ;,© in the case of the retterchitto* most of the foeoiliferoue beds are porous sand© which are deeply leached and th® fossil© are seen a© molds. These melds are found in the bed© as far northwest as the marine lenses are found. ifa© best fossil localities in the central ..tesieeippi area are found in the marls at the base of the formation in north** eastern wccit and northwestern Newton Counties. he bed© at these

localities contain about the same fauna as the archusa.

Cetrea gellaeforiaia is founo. as far northwest as fossils are found in the formation.

2M£E*£ g * » * ate-Va Mam liar

Introduction - Beneath the quaternary sands and gravels in northwestern no lms s and southwestern Carroll Counties* there outcrops a thick section of carbonaceous shales which constitute© a distinctive

lit h o logic unit. There ie very little similar m aterial in the 4h0 feet of overlying uea-marine Cockfield beds and the ©action below is predominantly a non-marine sand section with lenses ox carbonaceous

shale ana li-nitic, silty shale. xhia thick section of carbonaceous

cnale is herein named the hipp's Greek shale* the name being taken from nipp’s Greek* a tributary to Hack Creek in east-central Holmes

County* M ississippi*

i’be Shipp*© Creek ©bale is a t lea st in p art the ttra tig ra p h ic equivalent of the marine Jautubbee of central isslesippi because it

lie© a t the same stra tig ra p h ic horizon in an area a which son-marine 60 sedimentation ms continuous throughout tapper ana middle cl&iborn© time* The Shipp*® Greek occupies a position in the middle of th© section between the top of the Inona and th© top of th© Claiborne#

The marine autubbee occupies the earn© position in the ©ectien on the outcrop in centraI iseiseippi and in the subsurface section in Y&teo

County* The Shipp’ s Creek outcrop also lie® along the pro jectio n of the normal strike of the marine autubbee#

aith®lo^y - Lithology typical of thi® member is eel! exposed along practically every stream in th© ^oess Hills region of north­ western Holme* and southwestern Carroll Counties# rhe beet exposure® are lound on a series c, bluffs on Chicopa Greek and its tributary

Jordan’s Branch irhiliip*® Creek, in extreme northwestern ^okae®

County where 60 to 100 feet ci the section can be seen in the freed state* Iheee outcrop® are relatively inaccessible and so an exposure in a cut along the county road immediately south of the iron bridge across Shipp's Creek in the G3 of Ni5 of section 28/t15H/k3K and about

4 miles (airline, east-northeast of Lexington, relate* County, ....ise- ieei.pi was selected a® the type# The section here is *

COCKTICLD HGiilL.TIUtf

23* sana - iron-stainedj irregularly sodded to maeeivej abundant

slab-like pieces cf dark brown, limonitic sandstone up to

2 inches tfaiekj brown silt mantle

'itbTliBBiiS - G Kiln TICK

CilXKi *G K Otitil* . luizM&iuki *• 1 Vfo jLCTTCK

1 4 * carbonaceous shale - chocolate brown to light gray§ laminated

and with irregular partings ^nd interbede up to 4 inches 61

th ic k ui lighi gray soars® silt; fresh material highly ligniiie

and with as occasional f o s s il lea f; flaky yeli©w~brown s lit*

stone concretion® along silty partings; at th® top is a this

limo: ivio sandstone ledge of the type e© 3ansoniy formed. os the

top of shale sections by circulating ground-water

sand - gray to yellow to brown; very fin© grained and looses

few partings of gray shale$ grading down into

7^* sand - similar to above but more parting® and stringers of gray

to chocolate shale with abundant flaky eiItstone concretions

in the more weathered material £* carbonaceous shale - chocolate brown

6 ' covered

_ection continued beneath bridge

16* carbonaceous shale - black to chocolate brown; laminated; whole

mass regularly bedded, but individual laminae extremely ir­

regular and lenticular; partings, interbeds and pockets of

coarse silt; abundant fragments of plants and an occasional

fossil leaf

ater level of bhipp'e Creek - elevation 334’ (altimeter)

48* Total bhipp*s Creek section - base not exposed total section measured - 71 feet

The Shipp*e Creek member ie much oore lenticular than could possibly be illustrated on i late #* ih® carbonaceous ©hale® are inter* beddea and interlersed with silts and sands in an extremely comp lex manner* he best illustration of ibis condition is found in « com­ parison of the type section with th® section exposed at a bluff on 68 the south side o t ilhipp*e Crook on the Chuck owlniaey place about half a mile above the type locality and near the center of section 87/T1SM/

R3S* The eeeticn there is*

SBIFF* i, CRSBK SHAL^ M^tESR O f H3MATX0K

80* sand - light gray, white and yelldw~brownj very fine grained

and micaceous; partings, stringers and interbeds of carbonaceous

shale; this bed changes laterally into a carbonaceous shale

section at the lower end of the bluff (within a hundred yards)

6 to 8 * carbonaceous shale * black to chocolate brown; irregular

partings of medium gray, li&nitic, micaceous coarse siIt and

a few thin stringers of black lignite; shale nearly pure clay

and contains an abundance of plant fragments

3 te 5' sand - white to yellow-brown; bands and partings of black,

lignitlc concentrates and brown, lignifie clay; micaceous;

individual beds lenticular and cross-bedded l£* shale or clay - dark gray to black; silty and lignitlc; yellowish

efflcuresceece on slightly oxidised surface; lenses of light

gray edit; extremely irregular structure; this bed truncates

underlying bed

2£* coarse silt - medium gray to brown; micaceous; yellowish ©f-

flourescence on slightly oxidised surface; few irregular

partings and oriented blebs of gray, lignitlc clay

5 * silty shale or interlaminated silt anu clay - medium gray to brown; lignitlc and micaceous; structure of whole even-bedaed

and of individual laminae highly irregular and lenticular

:&ter level of >bipp'e Creek - elevation 840* (altimeter) lotal section measured * 40 feet 63

in addition to the carbonaceous shales add store or lese lignitie slits and sands* the Shipp*s Creek member contains a lew thin interbede of blaek, impure lignite*

Contacts - The lower contact of the Shipp’s Creek is conform­ able and highly transitional* it is arbitrarily drawn at the base of the section in which carbonaceous shales are the predominant facies in southwestern Carroll and northwestern Holmes Counties* as shown on Plate 2» the section in the eastern Holmes-southwestern Attala

County area is a lenticular mass of carbonaceous shales and run-glau­ conitic sands which cannot be satisfactorily subdivided and the basal contact is arbitrarily projected through this area on convenient car­ bonaceous shale lenses in order to Join the basal contact of the marine

-autubbee#

The upper contaet ie also conformable# it varies from sharply defined to transitional* but is a much more definite horisen than the

lower contact» since there is little carbonaceous shale in the Gock- field section in Holmes and rasoo Counties# This contact is projected across southwestern Attala County on carbonaceous shale lenses to join the upper marine autubbee contact* Both the upper and lower contacts are dashed on t la te 1 throughout the area northwest of the rockahockany

River because of their arbitrary nature in that area*

Thickness - The maximum development of the Shipp’s Creek is reached along the bluffe which border the alluvial valley of the Lies- issippi River* The thickness of the member hero is about SSOQ feet* that figure being derived by reference to subsurface contours on top the inona. The thickness decreases rapidly eaetward and ie only about 65 feet in the Ghipp's Greek area* The arbitrarily defined section i neluded in the ohipp#e Creek across eastern Holiness and southwestern 64

Attala Counties averages about 40 feet in thickness*

Fossils - Fossil leaves occur throughout the Shipp*© Creek but are nowhere abundant# They have not been studied in detail# Smal tatem s£ ££* aalgltea ftgasttta D istrib u tio n * The d istrib u tio n of the Wautubbee outcrop is sheen on Flat* 1* it is an irregular belt averaging about two miles in width and ranging from one-half to six miles wide which extends from the Alabama-Mississippi state line near Crandall, Clarke County northwest across the state to the bluffs in northwestern Holmes and southwestern Carroll Counties# Topographic Expression «# The weak carbonaceous shales which constitute the Gordon Creek member in eastern Mississippi and the upper portion of the u n d ifferen tiated Wautubbee of cen tral ;is siss ip p i give riee to a distinctive topographic flat or bench which greatly aids in mapping the formation# The ether beds of the section have no distinctive topographic influence and their outcrop is a contin­ uation of the sand hills topography of the Cockfield and Kosciusko formations#

o iIs * The m aterials of the Wautubbee give ris e to a number of different soils# The sparingly glauconitic to non-giauconiiic sands give riee to fine sandy loams or fine sands of the Huston»

Greenville, Orangeburg and Norfolk series which have been described under the soils of the Neshoba sand on page 22# The groeneando and highly glaucon itic sands give r is e to fin e sandy loams of the Nacog­ doches and allied series described under soils of the Winona and the carbonaceous shales give rise to the distinctive Boswell and Susque­ 65 hanna vary fine sandy or silty loams described under soils of the

Zi Ip ha*

Depositiona! Conditions * The deposition of the w&utubbee me initiated by an advance of tbe sea over the Kosciusko deltaic plain*

The maximum northern extent of this advance was to the latitude of southwestern ttala County* The decreasing thickness and lithologie changes of the formation along strike indicate that this advance prefer­ ably did net occur simultaneously throughout the area, but was initiated in eastern Mississippi and gradually extended northward to its maximum advance* if so, the upper part of the Kosciusko and the lower part of the Ccekfield formations of western Mississippi are the time equiva* lests of part of the autubbee section in eaetern Mississippi*

The disappearance of the marine Wautubbee section in south­ western .ttala County is net due to overlap or truncation of the marine section* This is evidenced by;

1* The marine lenses in southwestern Attala County do not lie at the same stratigraphic horisen as they would if they were remnants of a formerly continuous section*

2* The carbonaceous shales and marine sands of the Wautubbee exhibit a normal and conformable relationship in the area where it: e marine section disappears* The carbonaceous shales which normally overlie the marine beds are present throughout* They would be absent had truncation occurred*

3* The fhutubbee beds become progressively more shallow-water aepesits northwestward along strike*

This disappearance of a marine section is an example of what probably 66 happens t© ail marine sections in the Tertiary of the $ulf Coastal i lain is the area of maximum marine advance* in such an area non-mar** ine sedimentation occurs on the deltaic plain simultaneously with marine sedimentation just off-shere and minor retreats and advancee

©f the sea produce an interleaving of the two facies#

The ahundanee of the large oyster* C street sellaefom ie* and other &haIlow-water forms* the clay inclusions and the sandy nature of the Archuea sari indicate that it was deposited fairly near shore in clear, shallow waters in which lime was being precipitated# The lack of bedding and lithologic breaks and the homogeneity of the materials indicate uniform conditions throughout its deposition* The irregular bedding and lenticular nature of the beds of the I ©tterchltto indicate that it was deposited nearer shore than the Archuea in an environment in which current action was quite strong* This shallow­ ing of the eea corresponded closely to conditions during inona time#

The greeneande and glauconitic sands of the undifferentiated autubbee of central &iseiseippi were deposited under the same conditions ae the ietterchitte*

marine conditions were brought to a close by an advance of tte deltaic plain over the shallow marine deposits in the same manner that the deposition of the Zlipha ended the Tallahatta-Winona marine epoch#

The deposits which were laid down during this change from marine to non-marine conditions were incor;..crated in the section as the Gordon

Creek shale and the carbonaceous shales of the upper autubbee of central Mississippi* The sharp nature of the Gordor Treek -1 otterchitto contact indicates that this change was very rapid in eastern ; issiseippi* but the lensae of greenaand and glauconitic sand in the carbonaceous $7 shales throughout control liissisaippi anti above the main body of the formation in cent m l ^,oake County point to many minor* localized ad** vaneoo of the sea in that area*

The thick, non-marine section between the top of the Tiipha and the top ei' the Ooekfield in western Mississippi indicates unbroken deltaic plain depoeitional conditions throughout Kosciusko» autubbo© and Ooekfield times in that area* During Shipp's Creek time the shore line apparently drew near the northwestern Holmeo^southwestern

Carroll County area and marshy conditions probably existed while that member was deposited* 68

COCKFISLD FOBtlATXQN

Introduction ~ The beds in Miseissipoi which are called. Cock* field in this report were first noted by Hilg&rd (IT) in i860* hut lows (18) first gave them a formal name, calling them the Ooekfield lignite member of the Li ebon formation* Later author® have called them both Cockfi&ld and Yegua* Lost of these writer® have restricted the Ccckfleld or Yegua to the upper* mere shaly portion of the section herein called Ooekfield* in this report the formation is expanded to inelude all beds below the Moody*® Branch (basal Jackson) and above the autubbee* This usage is in agreement with the usage of the term

Cockfield in Usuieiana where the type locality is situated and gives the formation a definite basal contact rather than an arbitrary and highly transitional one*

stensel (19) has summarised the history of the names Yegtta and Cookfield* Be points cut that the type locality of the Yeg.ua. is in reality a part of the marine Crockett formation and that the term

Lufkin has priority over the tern legua* The only point in favor of retention of the term Yegua is its common usage* Cn the other hand the type section of the Cockfield is representative of the lithclogy of the formation and occurs near the middle of th© Ooekfield section*

The term Cockfielo does not have priority ever either Yegua or iiifkin,

(17) B* v?m Hilgard* Report on the Leo logy and Agriculture of the State of Liseissiopi (Jackson, tf.iee** B* Barksdale* I 8 6 0 )* pp* 127*128* (18) 3* R. Lowe* "Mieeissippi* Its Leo logy* Geography* Loiie and Mineral Resources," &ies» Jeol* purvey Bull* A! (1915)* p. 77*

( 19) fU B* otensel* '’The Yegua rrablem*" Texas Bureau of :: canonic apology 2241 U939), pp. 847-910. 69 but ie well established in literature and is preferred over

Yegua in thie report*

The name Ooekfield was proposed by Vaughn (SO) in 1895* He called the section the "Cecksfieid Ferry bode” after a locality in

Grant Parish, Louisiana* Veateh (SI) later changed the spelling slightly and abbreviated the name to Cockfield*

The Cockfield of Tiesieeippi has beer considered both a mem** her of the .isbon formation and a separate fomation* The tendency in later reports has been to give it formational rank and that pro­ cedure ie followed in this report because the section ie a well-de­ fined litho logic unit which has a wide areal distribution#

Lithe logy «► The lithology of the Goekfield bede is essentially the ease as that of the ioeciueko section* The basal 25 to 125 feet of the formation are composed of massive to highly cross-bedded, iron-stained sands* upward in the section lenses of shale become more and more abundant and usually predominate over the sands In the uppermost part of the formation* The shales are of both the carbon­ aceous and ligaitic, silty types described under the lithology of the Kosciusko* The transition from the basal, sandy portion to the upper sand and shale part of the section is so gradual that no logical separation ef theee two facies can be made in the field#

he shown on F la ts 2 , a marked lithclogic change occurs in the

-©ckfielL section in weetern L'ieclesi; pi* On the bluff© in western

(20) T# V* Vaughn, "The stratigraphy of Northwestern ouieiana," rAu:er« G eologist* Vo I* 15 (1895), p# 220*

(21) A. C# Veateb, "The Underground atere of Northern Louisiana and Southern Arkansas,* Louisiana Geo A* Mry

Ho Ieuss and northwestern Yaioo Co untie© the upper 300 feet of the formation consists of dark greenish gray 5, fresh) ie light grey 1 weath­ ered}* lignitic, argillaceous silt and eiiiy shale with irregular partings and intercede of lighter colored silt* Lenses of gray* lignitic* leaf-hearing clay and lignitic io sen-lignitic sands occur in the silts* The sands vary from black to gray in color* depending upon the lignitic content* and from massive to cross-bedded* Car­ bonaceous shales are very rare in this sequence*

Lignite ie abundant as beds up to 5 feet thick in the finer grained Ooekfield sediments* The lignites are typically black and impure* some of them chow roots extending down into the underlying materials and have obviously formed in place* while others appear to be composed o f m aterial transported to the s i t e of deposition*

The best exposures of the lignites are found along the bluffs where the outcrops are fresh* They are rarely seen on the surface in central and eastern tiesieeippi because of the deep weathering in that area* These beds contain an abundance of well preserved fossil leaves and other plant fragments*

thin stringer of tan bentonite which lies near the top of the formation ie found at a few exposures in extreme southwestern

Holmes County* Along the b lu ffs east of Tchula* Holmes County a a thick bed of quartzitic si itstone similar to the ledges in the

Kosciusko is found* The most common concretionary materials found in the Cock- field are the familiar limordtic sandstones and eiltstonee formed by circulating ground-waters# The lignitic* argillaceous silts and silty 71 sb&les contain both pyrxte and side rite concretions* The pyrit© con­ cretions are ema 11, cylindrical bodies which are formed in vertical* eilinfilled pipes in the argi1laceous elite# The pyrite binds the silt into an indurated pyritifereus eiItstone# The siderits occur® as rounded to spheroidal to flattened boulders which range up to 5 feet l&rgeet diameter and which occur at a definite horizon about

SO feet below the top of the formation in northwestern Yaseo and south­ western Holmes Counties* At a few lo c a litie s the arg illaceo u s s l i t s contain rounded calcareous siitetene concretions; up to £ inches in diameter#

Lower Contact - The C eckfield- mutubbee contact ie conformable and transitional, it is similar ie its details to the Koeciusko-Zilpha contact and represents the same sequence of events# Throughout central and eastern Mississippi the basal Ooekfield sand grades down into the underlying carbonaceous shale through an Interbedded sand and shale section which ranges from a few inches to 10 feet in thickness* scat­ tered lenses of carbonaceous shale are found in the basal Ooekfield sand# fit some outcrops in scott and Leake Counties the Ooekfield rests directly upon greeneands and glauconitic sands and the basal few feet of the Ooekfield contain glauconite which gradually disappear® upward in the section# a similar condition exists in the vicinity of autubbee station where the Ooekfield overlies the sparingly glauconitic s i l t s of the Gordon Creek member*

This contact is easily identified on the outcrop and makes a satisfactory mapping horizon as far northwest as the Yoekahock&ny

River# The details of the contact between the Cookfield and the Chipp'e Greek shale have been discussed under the contacts ©f the witipp's Greek on page 63*

yip per Contact * The contact between the Moody * s Branch (basal

Jaeksen) and the Ooekfield ie dieoonf erasable* The Moody's Branch is

composed of foeeiliferoue greene&nds and glauconitic sands which become more marly near the top ©f the section and whieh are overlain

conformably by the marine Yaaoo clay* the Moody's Branch is a basal*

canay concentrate which bears the same relationship to the overlying marine uaekson section that the basal* pebble-bearing glauconitic sand

bears to the main body of the Basic claystone and that the basal,

sandy portion of the ^autubbee bears to the overlying marine section*

The contact resembles the lower mutubbee and lower Basic

contacts in its details and represents a similar sequence of events*

The transition between the two facies occurs within a 1 to 10 foot

section in which the Moody's Branch and Cockfielb materials are in­

timately and heterogeneously mixed* The basal few feet of the marine

section contain email blocks and ether inclusions of material from

below and the uppermost part of the Ceckfield contains small pockets and filled borings and lenses of foeeiliferoue material from the bed above as well as disseminated glauconite*

The Moody'e Branch-Cockfi©id contact is a good one on which

to base detailed mapping but is seldom used because the Moody's Branch is thin and its upper contact is one of the beet in the Tertiary

eaction of Mississippi* Thickness * The Ooekfield maintains a constant thickness of about 50 feet across Clarke County and gradually thickens northwest­ ward from that area to & maximum thickness of about 450 feet in 73

Ho 1x869 and latoo Counties* Thicknesses under 75 foot were measured directly on the outcrop, these in the central part of the area war® obtained by a projection of dip® on surface contours and these iia the western part by reference to subsurface contours on top the inona#

Foeeila • There are a number of good f o s s il,le a f lo c a litie s in the lignites and leaf-bearing clays of the Ooekfield along the bluffs. The remainder of the outcrop Is so badly weathered that such localities are very rare. This flora has not been studied in aet& il.

Distribution *> The Cookfield outcrop is shown on 1 late 1, It forms a belt with irregular boundaries which trends about 45 degrees west of north across the state* This belt is quite sinuous in Clarke

County and ranges from ^ to 7 jniles in width, Northwestward from that area it gradually increases in width to an average of about 15 miles in western Mississippi,

Toppgraphie Txereseton - The basal sands of the Ceckfield support a rugged sand hills topography and form a marked escarpment overlooking the topographic bench formed on the weak shales of the upper autubbee throughout central and eastern Mississippi, The average local relief throughout this belt is about 75 feet and the maximum is about 125 feet. The upper,more ebaly portion of the

Ceckfield supports a more rolling sand bills topography in which the average local relief ie about 50 feet# These rolling sand hills merge with the very gently rolling Jackson or Yasoo t-rairie region to the southwest* oils - The Ceckfield sediments give rise to soils very similar to those found on the Kosciusko outcrop. The massive sands form fine 74 sandy loams and fine sands of the Huston and allied aeries* while the eands and shales give riee to fine sandy loams of the Hhubuta and allied series* These soils have been described under the eella of the Kosciusko and Kesheba*

As in the case of the Kosciusko, the soils of the Ooekfield in western Mississippi contain abnormal amounts of silt and in western Madison* northeastern Yazoo and southeastern Holmes Counties the outcrop ie covered by a mantle of brown silt which gives rise to eilt loam soils* in Leake* Hcott and ewtoa Counties the soils of the Ooekfield often contain an abundance of email, white quarts pebbles which are residual from a younger Iliccene or Pleistocene

(Citronslie) blanket which ones covered that area*

aeuositional Conditions - The conditions unuer which the Cockfield sediments were deposited were the same as those under which the Kosciusko beds were laid aown* The nature of the lower contact shews that the deposition was initiated by a rapid flooding of the coastal marsh by a thick section of stream-deposited sands*

The gradients of the streams on the deltaic plain gradually dimin* iehed and during upper ceckfield time considerably more fine grained material was deposited* Conditions were apparently much more marshy and swampy in the southwestern Holmes-northeastern Yazoo County area during middle ana upper eckfield time than elsewhere in the outcrop area ana a thick section of fine grained* lignitic material was laid down there* Kon-marine Ceckfield depoeitional conditions were ended by the concerted advance of the Jackson sea* m i s m m m E m m m IHTRtSDUCTXOS

ab generally accepted* the type Claiborne section cf western

.lab&ma consists of throe formations* They ares

Gosport fossiliferous sand

Lisbon sandy marl

Tail&hatta formation or *buhreton®w

This section ie entirely marine and is quite diflerent from the alter­ nating marine and non-marine Claiborne sequence of eastern iesieeippi*

The transition from one section to the other occurs in Clark®* southern

Choctaw and northeastern aehington Counties* Alabama* :n this area two large structural features* the natchetigbee anticline ana the Jackson iault, bring Claiborne beds to the surface which woula nor­ m ally be 20 to iO m iles down-dip from the normal outcrop* Marked changes occur in the laiberne section both along the normal outcrop ana down-dip (on structure;* Figure 2 is a diagram showing the author’s interpretation of the etratigraphic relationships of the

Claiborne &reup in eastern iiissieeippi and western .labaiiia* it shows only the general features of the correlation* since the problem is in reality quite complex and the data is incomplete in many instances*

Che largest and most important gap in the aata is along the normal

s trik e of the Claiborne group across Clarke County* liabema*

7S E astern M iss. W e st e r n A labam a

l,me,V~ 'eaoe

MoMvS - fas&Tat. -« CD Cockfieidl sa *sh 0 U I«? V © O .2JO '3 -O V-jQutuobee fro r£^32W FACIES ALONG ^ Jvrxtsto’li—7 ------NORMAL STRIKE $ FACIES ALONG ^ ' N b o . m r*| Kosciusko sd & NORMA l, SI R ia E r~ — ? ____ t^picAi USDOfl rr,a<"' ^ /y cttabq-'gr Kosausk© Equivalent' jfiinQna qfPPirt.sd | lowev Lisbon giaut sds

Basic cla^tore TallGbaHa Tollahotta ~ i h WEST EAST j g l ! % //, /

VlaaspovjA'ScuCeUa beL

DOWN-DIP FACIES F ig u r e Z - Diagram ’ Showing C orrelation of Claiborne

Croup of Eastern Mississippi with Type Claiborne Section of Western Alabama <1 By Paul thomas Ch vertical scale . - I "= iso'

H ORIZON TA L. S C A lE ~ l"= 10 Ml

! 77

Ta LLAH a TTa FORMATION

The Tailahatta formation takes ita name from the fallahatta

Hi H e in southeastern Choctaw County, Alabama where the beds are well exposed* The type section ie the lithe logic and et rati graphic counter'* part of the Basie elayetone of eastern Mississippi* The Ta1lahatta persists throughout western Alabama, averaging about 100 f$st io thickness and reaching a maximum thickness of 12$ feet* Most Alabama reports give this thickness as about 300 feet after Smith and John** son (22), but this is a carefully preserved error* The basal, peb­ ble-bearing glauconitic sand is persistent throughout western Alabama*

LISBON ANL SO SPORT FGHMATIONS

Introduction

The type middle and upper Claiborne section at Lisbon and.

Claiborne B luffs on the Alabama Liver in Clarke and Munree Counties,

Alabama and about 65 m iles along the normal strik e east-south east of the Mississippi'“Alabama state line has been described by Smith and

Johnson (23; and copied in most later Alabama reports* A generaii* cation of their lower Jackson and Claiborne section with the formal names later given is*

(22) 2. a * Lrnith and u* C* Johnson, Tertiary and Cretaceous Strata of the Tuscaloosa, Tombigboe and .,labama Livers,4* y* y* (looI* Aurvey Bu 11* (1687), p* 35*

(23) Ibid* pp. 29-30. 78

BEDS * T^*ff~*FMSB!NT NAME ——>»aw^^***W«»a»a*MWaMWWH»aa^^«*laaaidl»«»«l»aa»MwaiWaM*l»*aaaaaart>i«*Wail»aiaWIMI»ai»i»>l|n«li ^ ■ — <*«■■■»» white limestone * 4S* * Jackson ------a s M s i i a b€fd« ’ a* * ♦ « coarse glauconitic sand * 6* ' Gosport (24) * « sparingly glauconitic sand loaded with shells*IS-17* * ------*.**._«...**** ------t. - int orb ©tided glauconitic sandymarls, calcars*** 1 * 92* • ous clays andcalcareous sands * * » i glauconitic sands * 23* * ■— *■* • » « • » • * » Mfc «*> tm - Mr (Ml ■» *>B«nw>M»M>www «••* «•* ««» •• t» 4M *» (MU •*> H I W bluish black clay (only partially exposed; * 13' 1 T&liahatta

a very similar Gosport-idsboa section is exposed down-aip

along the Jackson fault on Little Ltave Creek about 3 miles north

of Jackson, Clarke County» Alabama*

The eastern Mississippi section which is equivalent to the above oeport-Lisbon section isi

* FORMAH ON * B 3DS * XHX CKNE S3 » * * J* A* * C*Uoody*s • Sandy, sparinglyglauconitic limestone * 1-3* K' * * fj* Branch f f osei liferoue green sand * 5-10* 0* N * * — r- — — — — — — — — — — — — — *Cockfield #* non-marine sands and shales * 50* • • ’’autubbee' saJa<*y marls and glauconitic sands with 20** , * * 8 0 * , * of carbonaceous ehal at top 4 » * * ’Kosciusko* non-marine sands * as 1 • * t * carbonaceous shales ' 10 •m p b a -t ------; ,ft' • 'inona * coarea-grainad, fo e a ilife rouegrsansanda ’ 10’

( 2 4 ) The original definition of the Gosport includes all beds below the white limestone ("St* Stephens limestone”) and above the Lisbon. 79

Sacfe of these eastern Mississippi formations has a litho logic equivalent in western Alabama*

Coarse grained greonsands of typical Vlnona aspect and carrying both «i8»iBBi»nl«»mia ana Qgtrea eellaeforals ZS£> MgfegS,“ ensis are found overlying the T&lianatta throughout laoot of western

^labama. They are absent te poorly developed along the crest of the escarpment formed on the normal Hallahatta outcrop, hut become pro­ gressively thicker and more marine in aspect down-dip on the Hatch®** tigbee anticline* Both the upper and lower contacts of this section are conformable, indicating that this is a simple up-*dip leasing out cf a marine section rather than an un conformable overlap*

The Winona equivalent its mappabls around the Haiehetigbe© anticline and occurs as a 2 foot section on id tile Stave Creek* The extent of its development along the normal outcrop through Clarke

County is unknown, but it is present as 6 fee t of ere $ embedded glau­ c o n itic sand with coarse-grained glauconite and quartz pebble© along highway u* 3* 43 near lameda, Clarke County, Alabama and can probably be traced into Lisbon Bluff where its probable equivalent is at least part of the 23 foot glauconitic ©and section which overlies the

T&llahatta, The distinctive lithology and persistence of these beds throughout western ^labama warrant their recognition as a member of the .Lisbon formation* m m The carbonaceous shales which overlie the inona throughout i ississippi are very poorly developed in western labaauu They are 60

found only at isolated outcrops and have little value as a mapping unit#

The massive to cross*bedded* ncn-glauconitic sands of the

Kosciusko of eastern Mississippi can be traced well into western ^la-

basa* This section averages about 65 feet in thickness along the

normal outcrop in Choctaw County, >1ate&ma and i s exposed over a wide area on the gentle slope el the ju far©tone Cuesta. Th® extent of the

development of these sands along the normal outcrop belt through Clarke County, ,labaraa is not known* but they can be recognised as

14 feet of medium t© coarse grained* pebble-bearing* non-glauconitia

tand along highway U* S# 43 near Alameda* It apparently lenses out into the lower part of the type Lisbon section In eastern Clark©

County* Alabama* These beds can be traced around th© southwestern flank of th© Latchetigbee anticline* They become progressively

th in n er down-dip and lens out near the Tombigbee Liver in northeastern

Washington County* Thee© sands form a ma^pable unit over a consider­ ab le area in western Alabama and should be recognized as a member of the Lisbon formation in that area*

autubbaa Saul valent or Typical Lisbon f.a.elge.

The Archusa member of the autubbee formation of eastern

Mississippi is in reality a tongue of th© marine Lisbon section developed at Lisbon and Claiborne Bluffs* Alabama* The potterchitto member contains essentially the ©am® fauna* but has a slightly dif­ fe re n t fa c ie s from any of the type Aiebon beds* while the Cordon

Creek shale ie a facies developed only where the marine autubbee

section ie overlain by non-marine beds and is absent at Claiborne

Bluff* The three-fold subdivision of the ^autubbee section of 81

eastern Mississippi can be made at soma iecalities, but the faeiee are not persistant ©nuugh to warrant subdivision of the section*

The typical Lisbon marl facies or autubbee equivalent of

Choctaw County, Alabama ie very similar to the autubbee section ©f

eastern Clarke County, Liesissippi* It ie quite lenticular, but can

be traced without serious interruption around the southwestern flank of the H&tebetigbee anticline into the down*dip ^isbon marl section on Little Stave Creek where it reaches 140 feet in thickness* The basal contact shows less and lees evidence of being dieconformable and tb s upper contact becomes mere and more gradational southeastward from the state line*

The extent of development an-; the relationships of this typical

^isbcn marl section along the normal outcrop belt In Clarke aunty,

Alabama are not known* The stratigraphic relationships in this area a re apparently quite complex because only 25 fe e t of fo s s llife ro u e ,

silty clay which might be considered to be of typical Lisbon facies are found overlying the Kosciusko equivalent along highway U« 3* 43 between lameda and Fulton* This section is only 20 miles along the normal strike from Claiborne and Lisbon Bluffs where the marl and clay seotion is SL feet thick* Cockfieid Equivalent

The Gosport eanu has long been considered to be the corr©la* tivs of the Ooekfield formation, although the evidence for this c o rre la tio n has never been adequately presented* Cooke (25} and

(25) C* T* Cceke, Equivalence of the Gosport Sand to the I oody's M arl,’* Jour* Ialeoptoloi^y* Vol# 13 (toy, 193® j , pp* 337-34Q* 82

Gardner (26) have recently presented stratigraphies and paleontological evidence in companion papers to show that the Gosport sand is at least in part the equivalent of the Moody’s x, ranch of Mississippi* Gtensei

(27) disagrees with this correlation on the basis of both etretigraphis and fauna I evidence - Bl&npied and tf&zsard (28)* a fte r d eta ile d fie ld work in western .labama* says w2t is the writer's opinion that th© lith e logic change from marine Gosport sands of southwestern Alabama to the non-marine Ceckfield of eastern Mississippi represents a lateral and gradational interfingering of marine foseiliferous green sands with lacustrine* non-fossaliferous sands and carbonaceous eiaye*"

The writer’s conclusions regarding the atratigraphic relation­ ship e of the Gosport* Moody’s Branch and Ceckfield ares

1* The uppermost few feet of the Gosport (as originally de­ fined) are probably the stratigraphic equivalent of the middle and lower Goody’s Branch of eastern Mississippi* the Moody’s Branch of

Clarke County* M ississippi c o n sists of an upper I to 3 feet of sandy* glauconitic limestone* while the lower 5 to 15 feet are foseiliferous greeneande*The upper Moody’s Branch ie tentatively correlated with thelimestone overlying the ”:>cutella bed” on Little Stave Creek on the basis of its field relationships and lithology* if this correla­ tion is correet* the upper part of the foseiliferous greensand section

(26) Ju lia uardner* "Recent C ollections of Gpper Tocene o i- lusca from *l&bama and M ississippi,’1 Jour* Paleontology * Vol* 13 (May, 1939,* pp. 340-343. (27) H. 0. ^teneel, o|-* cit. , p. £92.

( 2 8 ) B. A. Rlanpied and JW T. hassard* "C orrelation of Cock- field ana Gosport formations, Gas tern Mississippi ana estern .Alabama*” tin 1 i. J&fbXJ >’ • Jm%XJSlX* J&tiJU f Vol. BE (193B), p. 310. underlying the limestone on Little Stave Creek ie the stratigraphic equivalent of the lower foseiliferous greensands of the Moody*s Branch of Clarke County, Mississippi* since the Gosport sections at Claiborne Bluff and kittle stave Creek are quite similar, the same correlation probably holds at Claiborne Bluff*

2* The lower part of the Gosport interfingers with upper

Ooekfield ehales and is of upper Ooekfield age* Blanpied and Hassard

(29 ) record from 24 to 3? feet of Gosport in a series of core-ho lee in northeastern ashington County, vlabaica. The upper 10 fe e t or so of this section is the stratigraphic equivalent of the Moody's Branch of eastern Mississippi, while the lower part of this section can be seen interfingering with upper Ooekfield shales on the surface at the well-known 11low Branch locality a few miles northwest along strike from the core-holes*

3* The lower part of the ceckfield section of eastern Miss­ issippi is elder than Gosport* This lower Ceckfield section can b® traced around the southwestern flank of the Hatehetigbee anticline as far as the Temblgbee diver where it Lenses out between the Gosport ana typical Lisbon marl* Blanpied and Haas sard (30) record from 20 to 44 feet of "typical Ceckfield* underlying the full Gosport section in their core-holee in northeastern Washington County, but this

"typical Ooekfield" section i s absent across the Tombigbee Hiver on kittle Stave Creek* The full section of overlying Gosportacross

(29) B* Blanpied and i * T* Haszard, ibid* * p. 313* (30) B* W* Blanpied and B* T# Ha as car a 5 84

tiii® are* &M th© thickening of th© Liebon marl section with th© thin* ain g ©f th© lowor part ©f th© Cockflold equivalent iadteat© a» appor

14, ©boa ag© for th© lowor Co©left©14* SlCLflg DIFQ MTI PH A JL. P A T M

Several goolegists working in various parts of th© Gulf

Coastal I lain have recognised that the Tertiary beds were deposited

in definite cyclic patterns which are of fundamental importance to

a logical interpretation ©f the stratigraphy and depoeitional history

in that area* The Claiborne section of eastern and central Miseiee-

ippi exhibitb euch a cyclic dopes!tional pattern* it ies

diseonfonoity non-marine sand® and shales (top)

conformity

carbonaceous shale© or transition facies

conformity

marine facies (bottom)

ai©conformity

The contacts between the different lithe logic units in this pattern are quite similar in many of their details and radically dif­

ferent interpretations of their significance have been presented by

different geologists who have worked on the Claiborne of Mississippi*

Those contacts which are considered disconforwabls in this report are

horizons at which it can be established that an eresional break of

some importance occurred* The lines of evidence used to establish

this relationship are listed below in order of decreasing significance* 1, he litho logic nature of the underlying and overlying

materials - ■ sharp transition from non-marine to marine beds* such 86 a e occurs at th® base of both of th® marine sequences in th® Claiborne of eastern and central Mississippi*. could only be brought about by a strong marine advance accompanied wave-erosion.

2* The presence of a basal concentrate - The basal, sandy portion of the marine sequences are apparently beach deposits thrown up along the shore line as it advanced onto the deltaic plain* They usually contain small fragments and inclusions of material eroded from the bed below and incorporated in the beach deposit* similar features sometimes occur at conformable contacte, but they can be

logically explained by eubmarine erosion and it can often be proven by the persistence and constant thickness of the bed immediately below the contact that little or no truncation occurred* 3* The nature of the uppermost portion of the underlying section - in most cases where a marine section Use upon a non-marine section, the lithology of the uppermost part of the non-marine sequence changes over short distances from sand to shale to silt, etc*

This is exactly the condition which would be produced by truncation of the uppermost portion of the deltaic plain during a marine advance*

4* irregular line of contact * This Is perhaps the least reliable criterion for determining the exietence of a diecoaformity*

The irregularities must be of considerable magnitude before they have any significance* since slight irregularities occur along most con­ formable contacts and along many minor breaks or diastems within mar­ ine sequences# The filled borings which occur at dieconforraaile contacts in th e Claiborne of Mississippi have little or no significance in th© interpretation of the contact* since the.y are common within the 8? marine bids afid at conformable contacts wit bid marine eaquences*

The contacts which arc considered conformable in this report are boricons at which no significant break in sedimentation occurred*

The lines of evidence used to establish this relationship are listed below in order ©f decreasing significance*

I# ab interbedding of the two facies at the contact

2* rersistent lithology ana constant thickness of the upper­ most bed of the section immediately below the contact

3* The lithology of the section involved - If the beds above and below the contact were deposited under essentially the same environment, the contact is normally conformable* Also* the presence of a carbonaceous shale section or transition facies indi­ cates a change of depoeitional conditions during which there was continuous sedimentation.

The field evidence indicates that the sequence of events which caused the formation of the depoeitional pattern in the Clai­ borne section of lliasieeippl wass

1* A strong advance of the eea over a low-lying deltaic plain 2. Deposition of the main body of the marine section under off-shore, shallow wafer conditions

3* Cheating of the sea

4. a rapid advance of the coastal marsh over the marine eedimenti

5m Flooding of the marsh by stream-deposited sands

6* Gradual replacement of stream deposition by more marshy conditions 7# another advance of the sea over the deltaic plain 68

Fiek (31)> in a discussion e-f th© causes of similar ©vents in

cantral Louisiana during Cligocene and >oce»e time, attributes them

to subsidence under sedimentary loading with the shifting of the ©enters

of deposition accounting for the advance© and retreats of the shore

line# Subsidence under load has probably been a major factor in the

sedimentary history of the Claiborne section of Mississippi because

the presence of a thick section of bed© which have accumulated at or near eea level can most logically be explained in that manner» but

there is some reason to believe that other factors may also have

played a part in causing the transgressions and regression© of the

Claiborne sea* The indications of this aret

I* The rapidity of th© widespread marine advances * Th© field

evidence indicates that the Tailahatta and tody's Branch marine ad­

vances occurred rapidly and covered wide area©* in a i l p ro b ab ility

they occurred in the face of non-marin® sedimentation* There are no

large, nearby deltas of contemporaneous age which would promote

lateral downdragging sufficient to permit such advances and the Clai­

borne beds are predominantly sand© which would undergo little com­

paction* 2* The rapidity of th© change from marine to non-marine

deposition©i conditions - The field evidence indicate® that a sudden

acceleration of the rate of sedimentation caused a rapid advance of the laud into the eea over a wide area during each change from marine

(31) H* K« Fisk, *’Th© Geology of r.apides and ©stern .voyelles lu rieh e© ,” L.Q ul slana P ert* Gone* Geo I* Bull* SS9 (1940), pp* 126-127* 89 t© non-marine conditions* Againy the absence ©f any large Claiborne deltaic mass nearby precludes the poaaibiiity of a shift of a center of deposition which could account for such a widespread acceleration

©f the rate of sedimentation. Ihe moat logical explanation is that the gradients of a number of smaller streams were suddenly increased.

3. Largs overlaps exist in the 'scene section e.icng the Atlantic Coastal lain and there is no reason to believe that the factors which caused them did not operate elsewhere in the Coastal

Plain Province.

m the writer’s opinion 9 thee® points indicate that epeir©- genic movements probably played an important role in causing the oscillations of strand-line in Mississippi during Claiborne time* AUTOBIOGRAPHY

The author was horn on October 25, 1913 a t Are©, Idaho*

He received hie grammar and high school education in the public

schools of Boise» Idaho, graduating from high school in June, 1931 with high honors* He studied on© year at Edinburg, Texas, Junior

College ana transferred to Oklahoma Agricultural and Mechanical

College where he received hie Bachelor of science degree in Civil

Engineering in January, 1935* ..s an undergraduate, he wae a member of ; hi Theta Kappp. and I hi Kappa Phi honorary scholastic frater* cities, belonged to several student organisations and wae a basket*

ball lettenaan*

upon graduation from college, he worked for two years as a petroleum geophysicist and resigned in January, 1937 to return

to college at Louisiana state university where he received hie

aster of science aegree in neology in July, 1939* in April,

1940 he left school to take a job as field geologist with the

Ohio Gil Company* That company granted him leave of absence in

September, 1941 to return to school to complete work on hie

doctorate in Geology* EXAMINATION AND THESIS REPORT

Candidate: Emil Paul Thoms

Major Field: Geology

Title of Thesis: The Geology of the Claiborne (Eocene) Group of M ississippi

as Far North as Grenada County

Approved:

Major Professor and Chairman

WDean a of the Graduate /JichfJWl

EXAMINING COMMITTEE:

Date of Examination:

F ebruary 2 0 , 1 9 4 2 LEGEND . i P l a t e 2 « i NON-lGLAUCONITljC SANDS Comro5ite Diagram Showing F a c i e s C h a n g e s a n o T h i c k n e s s e s in t h e s J P SHALjES, ARGILLACEOUS SILTS AMD CLAY^ J S h r R a c f C i .a i H r n f S fc -h-io n Across MissisKippi j ______- A H A “ “ GO^lJfCONTTTC'^Al^DS A N IT j ~ ! j i i b y R a u l I T h o m a s J SILICEOUS CLAYSTONE, S1LTSTONE AMD SANDSTONE

^ j? SANdY MARL LOTH ; E x p l a n a t i o n — T h is d ia g r a m is constructed f r o m - d a ta o b t a in e d f r o m highw ay ! _Tinrm Oi IAR|TZ1TIC __SlLTfeTQNE.S j______J __ 'PRO'FIEET; “MEASURED SECTIONS; SURFACE CONTOUR5',’ TTEEETljMF^M'ATI'Ohi AND RE- ■ A *— LIGNITE i S CONNAISSANCE MAPPING. IT SHOWS AlL OF THE ESSENTIAL FEATURES oT THE SECTION COLDFIELD FM IN THE AREA MAPPED. HORIZONTAL INTERVALS INDICATE DISTANCES ALONG STRIKE AND VERTICAL INTERVALS DENOTE THICKNESS OF SECTION. SYMBOLS DENOTE; FACIES. THE TOjVNS AND VILLAGES AND A FEW SPECIAL LOCALITIES ON THE OUTCROP ARE SHOWN ] BESIDE Y ER T T?t''”ARROWS'T/VRlCFrTNDT'civrE'THErCTioEOG1C“ SECpTON””'EARO^EITW'7WD_“j“ " AROUND EACH, T H E DATUM PLANE USED IS THE ZlLPHA'WlNlQNA CONTACT. A MORE j COMPLETE explanation IS INCLUDED IN THEl REPORT rSH\PP's" CREEK SHALE

iCOCKFtELDj FM. ■

S^ARchu |a Marl WAUTUBBEE FM

KOSCIUSKO FM ZILPH, \5 H A L l WINON,A GREEN SAND j IIMSona TIscEnBME NESFlOBA SAND BASIC c u a y s t o n e u n d i f f e r e n T ia t e d HOBA SAND- I TALLAHATTA FM.i a sic I layst MCADAMS ELEVATIONS ABOVE SEA LEVEL APPROXIMATE E. N U CENTELR- ROFLE O HIGHWAY OF E FIL O PR F CtROUNp OF U G j SN HIL; SAND RUGGEjD OTEN USIT O KOSCIU: OF OUTSKIRTS NORTHERN 5 TOPOGRAPHY .5 L G e o lo g ic P r o f i l e a lo n g S t a t e H ighw ay ay ighw H e t a t S g n lo a e l i f o r P ic g lo o e G ______I | j j j ! | I OESMOS ERSN FCE, NOT FACIES, REPRESENT NOTE-SYMBOLS ___ OMTOS SE EED N LT TWO. PLATE ON LEGEND SEE FORMATIONS. _____ I E S RM TRIG POINT STARTING MILEjS FROM to \ B RU TOA j C. 14 I 1940 OCT., j THOMAS RAUL ;BY VERTltAl VERTltAl M c OIOTL -f=I - f MILE " HORIZONTAL A s m a d A , 0L „jsT_ L- 50ALE„rjEsQTX__ ttala

Co., 12 NECESSARILY rii l e h t E r a e n froi^i M iss .

j— ..... t w i p u f eb e n L ^ t t e 5 +irinqe>r Ly' EN OUT5KIRT5HERN F TE I ETHEL OF

P ofile ro T0G.O

D BROWN SILT MAMTLP ON TERTIjARY - BECOMING PROGRESSIVELY THINNER EASTWARD

TYPICAL SAND luPOGSAPiiY ELUDES TYPICAL LOESS M1LLS TQPOGRA ses o'T a

$ * V*

'ftp* Tfi sha/es

.: • '- J & r ' O^T“ jX^ 1

TH[p AREA STRUCTURALLY [|lS t a B I G eologic P ro file along H ige □ 5 8 2 FROM LMICHAEL T O THE LUFFS

QUATERNARY OLL AND M oNTGOMERY DEPOSITS PAUL THOMAS OCTOBER

VERTICAL'' SCALE HORIZONTAL = I M.

fNOTE - SYMBOLS REPRESENT FACIES, NOT NECESSARILY FORMATIONS. SEEi LEGEND o n ! p l a t e t w o

Center-line; profile ok maHwAT

ClT (jj i A pproximates ", “ &r o u Y>

NORTHERN OUTSKIRTS OF WINONA CARROLLTON 1; Ml. NORTH KILMICHAEL I

R or

MILES FROM TING POINT

Profile El ELEVATION ABbVE SE A -L E V E L l g n o l a J ^ l l r o r P . c i g o l o e G . ! - v 1 I ______o t N n o t w e l f TnTAj J H O PTZnMTjALj f 1 I .- - : ~ : -t • .- J N , Y Ab TOA FB, 1^41 FEB., THOMAS PAlbL BY OE - SMOS RPEET FCE, T 0 N FACIES, | (REPRESENT SYMBOLS - NOTE! EESRL F MAI ^ E LEGEND SEE N^ ATIO RM FO NECESSARILY n PAT T TE PLA on! a b o h s e j ETCL CL T=50 FT 0 T=5 SCALE VERTICAL ghway a w h ig h f o e l i f o r p - ^ T r e t u O mate profile e l i f o r p e t a im x o r p p A lNAT ETR NIAE CH/ApTY INDICATES LETTER - jlONTACT D L S O P x E

d n a . - e t a t S

i . iio N . P ofile r ewton ghway y a w h ig H ______of \U d n u o r g C Lj*_Li41L£ es ie t n u o

15 ___ l i h P m o t f M , 4 ------

ssi ppi p ip s is s is

..... ‘ - ...... * DECATUR YIA SN HLS TOPOGRAPHY HILLS SAND TYPICAL IE FO SATN POINT STARTING FROM MILES DE O FST N UNllON IN OFFSET TO DUE I OE APRN DP REVERSAL DIP APPARENT NOTE- UNION BENCH..M Z.ILPHA BENCH..M TOPOGRAPHIC

5 &K 0& ^5H E 5 - t p - H RPY O^J*RAPHY WINQNA FLAT-TOPPED IG TdPOG-^ RIDGE IPA E L A H S ZILPHA

NESHOBA YIA RLIS I ROLLINS TYPILAL TjL SOE Pi- SLOPE GTNjlLE OORPY Q TOPOGRAPHY i w N a n o

a t s e u c n |

Sasic ViLsLpe e s I lens P rofile C P rofile

o l o g ic P r o f i l e . a l o n e . H ig h w a y US 11 .f r o m B a s ic

to P a c h u t a C l a r k e a n d L a u d e r d a l ^ Cos.. Mis^.

feY PAUL THOMAS MARC! VERTICAL SCALE I* = 50 FEET 1 . tiOSlZcjlslTAL V___

SYMBOLS ftEPRESENT PACIES, NOT NECESSARILY FORMATIONS. 5EE LEGEND ON PLATE TWoj

C en te r - li^I e pr o f il e of highway 1 A p p r o x i m a t e p r o f i l e o f g r o u n d

E x p o s e d c o n t a c t - l e t t e r , in d ic a t e s q u a l it y

f A- lens of pjaty C op&l ine siljfstwie

WAUTUBBEE STATION BASIC CITY PACHUfTA 0.1 k WEST WEST ENTERPRISE 0.1 |MI. E.

10 f •; i [MILES 50UTHI OF STARTI N 6 POINT

P rofile B TYPICAL 8UH RSTONE HILL.5 TOPOGRAPHY ON Bit TH SIDES OF HIGHWAY

■; • • r- T"'v ■■■>-'» -r t ■fT f ■ A r P r o f il e A! SAND HILLS TOPOGRAPHY SUPERIMPOSED G e o l o g ic P r o f il e a l o n g H ighway U S 4f> fro m M eridian to Q u it m a n , ON GENTLE SLOPE OF ^ CUESTA

C l a r k e a n d L a u d e r d a l e Co s ., Misls. I^^eAUL^mQMAS EEEUaAJ . iTT VERTICAL SCALE -5 0 FT HORIZC NTAL = I MILE

NOT$-SYMBOLS REPRESENT FAQIES, NOT NECESSARILY

Centel line p r o f i l e of h ig h w a y FORMATIONS. SEE LEGEND ON PLATE TWO ; * i------—.— ------A ppr ox IMATE PROFILE GROUND

4 :44X1.4.-

TYPICAL SAND HILL$ TOPOGRAPHY

<

6LAOKT0P CONCRE.TE SLAB

QUITMAN

SOUTH OF STARTING < POINT

I M

Profile. A 7E ■*U ------5 / | ip Ewx ! i : n LE 6E .N D

pyroia h A. QUATERNARY DEPOSITS - sounds and gravels and loess

Jackson group

j COCKFiELD FM. - 50 to 5 0 0 ft. of non-marine sands, silts, ' ft shales and days with lignite, sideritc, bentonite, etc , heterogeneous

VilAUTUBSEE FM. - S to ZOO ft. of fossiliferous marls, greensands, Du£*j Hiu. C o° o uJ a Lk O 3 glauconitic sands and limestones with associated carbonaceous ° § clay or shale, non-glaucomtic sand, bentonite, etc ; becomes lilf e LU g non-marine northwest of the Yockahockany River.

> £ Kosciusko fm. - 75 to 450 ft. of non-marine sands silts, < o shales and clays with siliceous siltstones, etc. , heterogeneous C a r r o l l t o n Vs \ \ H 59 (X < Z lL P H A ’ SKALE - 0 to 7 5 f t of carbonaceous shale and UJ -J Kil m ic m a e blocky day with si It, sand and glauconite fw. °

IWlNONA GREENSAND ~0~S0 ft. of more or less fossiliterous medium to coarse-grained greensand

V a i d e n TALLAHATTA FM. - 5 0 +0 175 ft. of siliceous claystone Silfstone and sandstone , non-glauc. to sparingly glauconitic sand , greensand, carbonaceous shale, etc ijucks'ior Hill W ilcox g r o u p

Ek. m------In d e f i n i t e or A r d i t r a r y c o n t a c t 3 Definite contact

Q CTH£L LEXINGTON 'TEUN. v • J i Kosciufisa; »** « : Mi-V *

Yi> Ew< -Mi ) JacKsco

i

SKETCH SHOWING REGIONAL POSITION OF AREA MAPPED HILADECPHIA

\ IZE xj

5 /—d l-tc Kills bo s. (De^ tu^ ;

M: .: L -A-'OV T : ri,\ \\ i . ji t,' 1 : fT-ijjErrjn v (: :ulf& Meridian LJ I a IK t e s t be. *• rvEJ’ 1GE

N e w t o

T

PLATE I - GEOLOGICAL MAP OF THE IV V "WlRV

CLAIBORNE GROUP OF MISSISSIPPI ' * Rose. H ill 3 AS FAR NORTH AS GRENADA COUNTY

GEOLOGY 3Y PAUL THOMAS P a c k u t a sd x WITH ADDITIONS FROM THE MADISON CO. MAP OF C L. MOODY G rande ALABAMA 1941

6 r".1— , W —ia .i == MILES s t e p h l k s o n MISS. 6E0L. THOMAS HARPER H ILG A R D HILGARD JOHNSON C R ID E R & CRIDER LOGAN BROWN LOGAN LOWE LOWE LOWE LOWE COOKE ; G R IM MELLEN MELLEN FOOTER THOMAS L 06A N ^ WAP J O H N S O N SO CIETY 1941 1 8 5 7 18 G 0 I8G 7 1 9 0 5 1 9 0 G 1 9 0 7 1 9 0 7 1 3 0 6 1915 1919 1 9 Z 1 - 2 5 1 9 2 .5 1 9 2 5 IN G -192B 1 9 5 G 1 9 5 9 1 9 4 0 1 9 4 0 1941 1 3 0 5 1 9 4 0 Prelim. Rpt on Rp+ on Geol. ^ Amer. Jour. US Geol. Sur. US Geol. Sur. Miss Geal Sur US Geol. Sur. Cloib-Wilcox This US Geol Sur Miss Geol. Miss Geol. Miss. Geol. Miss. Geol Hiss. Geol Miss. Geol. US Geol. S ur Miss Geol. Miss. Geol. Miss. Geol. Miss. Geol. T his Geol i Aqric. o-f Agric.of State Sci. Icmd Arts) WqL Sup . Pop Wat Sup. Pap Bier. Rp+. Wot Sup Poc Field Trip R e p o rt Bull. 2S3 Sur. Bull. Z Sur. Bull. 3 S ur Bull. 4 S u r Bull. 12 Bur Bull 14 S u r Bull. 20 PrH Pop 140-E Sur. Bull. SO Bur. Bull 38 Sur Bull. 39 Sur. Bull. 41 Report State ot M iss ... T X L z ...... t v-: v„. 114 159 part 2. 57G Guidebook ' T1'" ...... 1 1 — .... znr E. w E I w. E. I W E. W. E. w. E w E w. E w. E W. E. 1 W. t. W E W. E W Winston Co. E. W Yozoo Co. Lduderdale Co TF Miss. Miss Miss J Miss. Miss. | Miss Miss. Miss Miss. Miss Miss. Miss Miss Miss. Miss Miss MISS MI55. Miss Miss Miss. Miss. Miss i Miss. Miss Miss. Miss Miss, only only u_ FM 5. only CO UPPER Hgniitc beds, L | * i } \ockt‘ielJk 'Cockfielct Yegudbr Coc. 'Cockfiek 1 1 UPPER UJ 1 Yeguti fm. UJ EOS + SHS | Yeq^a fm. Yegua fm. Cockle/dor Ytgua SOS. i SHS U_ below Jackson uncm untyff ■ignite mem. me m. field fm. or Ydgua Li_ ■ —i— — 1 CrU LOWER, Orange sd Orange Cla/porne “X C/J/b. UDWER, O 'ette L ot ayetfe 1 11 Yegda fm. mem. O MASS. SO (Miocene) sand La fay 1 i " MASS. SO. 3 1 f ■ | ' 6 s! V O u_? ! * !T u J 4 Aj 1 L O uJ Calcareous § c i . Sj UJ cQ mentions Lis­ Lis­ Lis­ L is­ Lis­ T) 1 I f f 5 * o aQ CO i 1 f: ^ ■§ <} r CO Calcareousdatb. or "5 ^ o JJ :o outcrops pt bon bon i *0 bon bon CO 1— bon t | | 4 i § s I— C/aiborne Claiborne Lj V) I | 4 ^ i 1 § > •X ZD Quitman fm fm. mar! mar/ mi . '-v.‘O ' | ■D T T I s c JO 4 S- 1 $: J ' - T — -T~r-.. 1 P 3 ’ y - 'fc o V 1 1 ^ JsF ^ 1 k / Coschgakot 'osahsLo vuskt JCoscuskoK rsciusko UT Orange Lafayette Lafaye tte I 11 QUARTZITl Orange sd. | r a i ■51 | i iftncbtone I 1 SD QUARTZITIC ZD 5.1.1 ---- _L SILT5TONE5 das/'t siltstones ' 5=1 (Miocene) sand s f § : § ‘ s T me 0 /?7i im. 5 1 3 3 mem. mem. \ *0 ! & KOSCIUSKO 3 T) \ : Cil r I It 1 _S .i -L § < s: S: ' b <4 JZ Ps Y § r5 JZ 7 * T j 1 K Vi § 3SI CL D- .*o T . t ■e <5 g §1 1 i . 1 § r- -3 1 -J ’ N ! O , * 0 1 s I | L- A 1 ...J «5 D S5 Sc fv i L | .. 3 i § V,s * < S 1 £ NESHOBA 1 |5 ^ 1 ^ § -t: i ^ ^ NESHOBA h- | >r 1 1r ii . . . . . r L - i t W i § " \ f i t 1 t t ' f e !■' TL < . ^ I 1 FJ £ & Siliceous * T | £ * 1 ' 5 5 Aluminous 5/hceous V ^ vj -T T allakdttcd Ta/la.iaffa ic ts Ttfllbhiaffa TaHahafta BASIC S T To Tgl I n BASIC _J Chib, or -5 1 ! is sandstone Claiborne 1tj ^S' i ^ X formnfion f. 77. m. f o r t?wt/on fo r m a tio n § § ' Buhrstone £ £ > IS ■*» I 3r | < § 5 TALLAHATTA i§ 5 1$ $

FIGURE. I - TABULAR SUMMARY OF THE HISTORY OF CLAIBORNE NOMENCLATURE IN MISSISSIPPI