STATE OF TENNESSEE .

Y STATE GEOLOGICAL SURVE .

N l on . e s Wilbur A , State Geologist .

B ULLETIN 22

o gy and Natur Re s ourc e s

0 Ruthe r o rd Co unt y ,

Te nne s s e e

GA LLO W A Y By J. 1 .

N V NN . ASH ILLE , TE ESSEE I9 I9

STATE GEO LO GICA L CO MMISSIO N

E ha irman . C A . H ROB RTS , ,

Gover no r Te nness ee of .

DR . . N H . A MORGA ,

Pres id ent nive rsit Tenne s e U o s e . , y f

D R . . . F M MCREE ,

o mm iss io ner A ri ulture C 0f g c .

N . V A W . E A S ,

hie Mine Ins ecto r C f p .

D . D R . . N J H KIRKLA ,

l r a nd e r il er i Cha nc el o V b t Univ s t . , y

N BISHOP A . W . K IGHT ,

- i r o uth Vice Cha nce llo r Un ve s it o th e S . , y f

GEO LO GICA L CO RPS

N N WILBUR A . ELSO ,

tate eo lo is t S G g .

D BRUCE WA E ,

i e o l is t As s s tant State G og .

D ND J . I . . HI S ,

h emi st C .

Z J . A . SWIT ER ,

d rauli E n ineer Hy c g .

D D " R . S . MA O ,

Fo re te r s . Table of Contents

Preface — Ch apter I l ntrod uc tion Towns Railroads and Roads Clim at e Ec onomi—c R esourc es Ch apter II Top ographic D es cription Rim of Hills Th e Central Plain D rainag e Glade s Kinds of Glade s O rigin —of Glades Chapter III TO pogr aphi c History Stages i n th e To p ographi c His tory Th e Highland Rim Peneplain Stage High T errace Gravel Stag e Th e Central B asin P eneplain Stage Th e R ec ent U plift Th e Shap e of th e Central B asin Ca es S nk - Ho es and n er roun D ra na , U g g e v i— l d d i Chapt er IV D es criptive Geolo gy His tori cal Revi ew Stratigraphy and A real Dis tribution R ocks N ot Exp os e d at Surface Rocks Exp ose d at th e Surfac e O r dovi c i an Sys tem Stones River Group M urfrees boro Limes tone Name and D efinition A real Di stri b uti on Thi ckness Charact er Comp osition Fos s ils Soil Pi erc e Lim es tone Nam e an d D efiniti on Thi ckness A real Dis trib ution Charac t er Stratigraphi c R elations F ossils Soil Ridley Lim es tone N am e and D efinition A real Di stribution Thi cknes s Charac ter Stratigraphi c Relations TABLE O F CONTENTS

Leb anon Formation N am e and Definition

Thi cknes s

Stratigraphi c R elations Fos sils Soil Black River Group Carters Lim est one N am e and D efinition A real Distrib ution

Stratigraphi c R elations

Soil Trent on Group Hermitage Formation N am e and D efinition A real Distrib ution Thickness Charac ter Stratigraphi c Rel ations Fos sils Soil Bigby Form ati on Name and D efinition A real Di s trib ution Thicknes s Charac ter Stratigraphi c Relations Cannon Limes t one N am e and D efi nition Areal Di stribution Thi ckness Charact er Stratigraphi c R elations Fos sils Soil M aysville Group Leip ers Formation Name and D efinition A real Dis trib ution Character Stratigraphi c R elations U nconformity B etw een th e Cannon and th e Chattanooga Shale Carb onifer ous Sys t em Mi ssi ss ippian Seri es Chattanoo ga Form ation N ame and D efinition 4 TAB LE or CONTENTS

Stratigr aphi c R elations For t Payne Formati on N am e and D efiniti on A real Di s trib uti on Thickness Charac ter Stratigr aphi c R el ati ons Soil — Chapt er V G eologi c Struct ure D e finition N as hville Dome Sm all Folds Faults Joints — Ch apter VI Geo lo gi c Hi s tory O rdovi c i an Tim e M urfreesb oro Ep och Pi erc e Ep och Ridley Ep o ch Leb anon Ep oc h U nrecor de d Interval Cart ers Ep och U nrecor de d Interval H erm itage Ep och U nrecor de d Int erval

Cannon Epoch U nrecor ded Interval Leip ers Ep och U nrec or de d Interval Carb oniferous Time Missi ssippi an P eriod Chattanooga Ep och U nrecorde d Int erval

Sub—sequent Event s Chapt er VII N atural R esourc es Soil B uilding Stones Road M at eri al

Coa O il and Gas l , Mi s c ellaneous Mi neral s

L T O F IL L U S T R ATI IS O N S . — a e I M a of R u er or oun n P p f C y, S ow g P ys ograp c R eg ons " l t — th d t h i h i hi i Plat e II —Diagram Sh owing th e To po graphi c Hi s tory of t he Central Basin a e enera e Sec on of the R ock s i n Ru er or Coun T enn 30 Pl t III G liz d ti th f d ty,

M APS . In ocke on ack Geolo gi cal M ap of Rutherfor d County . p t b Geology and Natural Resources of Rutherford n Tennessee Cou ty,

GA O W AY By J. J. LL

PREFACE

The survey upon which the present report is ba s ed was made in summer o f 1 9 1 5 f o r the Tennes see Geological Survey and the

sur nt o f Agriculture of the University o f Tennessee . The

N . onducted w . . by the riter in association with Mr H Coryell , h ffi a University , to w om he is especially indebted for e cient The mapping of the are al geology of that part of the

o f 62 included in the Woodbury quadrangle , an area square

was D r . . r . f D . . o les , done by . E O Ulrich and R S Bassler , the 1 0 . f o 9 8 . S Geological Survey , in the summer The base map f o r the parts o f the county included in the Mur N Woodbury , Hollow Springs , and ashville quadrangles was

d by . the U . S . Geological Survey . The remainder of the

was . surveyed , for the base map , by Mr Fred Maloney and 1 1 . o f . 9 5 M Ferris , Knoxville , Tenn , in the summer of .

l m ent r no w ed D . . . g is also due to the late A H Purdue , State

lo ist f - r o D . . c o . g Tennessee , for his hearty operation ; to E O Ulrich

s o f his ervices in the identification the geologic formations , and to

C . A . Malott for valuable assistance in the interpretation of the

” ra hic p history of the county . e purposes o f the survey were " ( 1 ) to determine the natural ces o f the county ; ( 2) to gather data for a detailed study of

3 f or th e o f the geology ; and ( ) to furnish a basis study the soil , in

t o an endeavor increase its productivity and to reclaim waste land .

The soil survey is not yet completed . A report on the paleontology f o N . . the Stones River group is being prepared by Mr . H . Coryell CHAPTE R I .

INT R OD U CT ION

Locati on and E xt ent

Rutherford County is the central county of the State . The geo graphical center of the State is on an area of bare rock o f about ten a two - o f cres in extent , and one half miles northeast Murfreesboro on the Lascassas pike . The county is also near the center o f the p

i r hi s og ap c region known as the Central Basin . f 607 The county has an area o approximately square miles . u bounded on the north by Wilson Co nty, on the east by Cannon

ff e s Co e counties , on the south by Bedford and Marshall countie , D on the west by Williamson and avidson counties . T boundary follows approximately the watershed or divide D Stones River and the uck River drainage basins , and the w boundary was designed to follow the divide between the Stones and the Harpeth River basins .

i a o f The east , south , and west boundar es , and also p rt the no

one . u , are very irregular Many of the irreg larities were made the State Legislature in response to petitions from farmers who 0 “ ” r land along the line , in order that the liners might pay thei t

V r and ote in the county which was most convenient f o them .

i s t county , however , largely a natural geographic uni .

T owns

Murfreesboro , the county seat , is the largest town in the co and has a population O f about It is the most important ing center in the county and is accessibl e from all directions by pikes . It is near the center o f the county and the cente best farming country . It has several important industries w

two to its prosperity, among them , pencil factories , a cedar wooden ware factory, cotton gins , sawmill , cedar post factory, and a flour mill .

n w w Other important tow s are Smyrna , a rapidly gro ing to n in

. a good farming region , Christiana , Eagleville , Fosterville , and Lavergne Scattered over the county at distances Of from six to twelve miles from Murfreesboro are numerous little villages which support one or two stores . INTRODUCTION

R ailroad and R oad s l N 81 . One railroad , the ashvil e , Chattanooga St Louis , traverses

o f e county from northwest to southeast , through the towns La

e Smyrna , Murfre sboro , Christiana , and Fosterville , and it is

of the principal assets of each o f these towns and o f the county . N u ther railroad , the Louisville ashville , follows the co nty

o f f o r west Eagleville about three miles , and furnishes an outlet

r produce from that locality .

The co unty in 1 9 1 8 had 1 03 miles o f toll pikes and 1 3 7 miles of

40 - w . 0 unty o ned pikes There are about miles of second class roads ,

tl w th e y improved dirt roads , which are o ned by county , and

the same amount o f third - class o r unimproved and private

- o f About one third of the county, the third which Mur

w h . oro is the center , is adequately supplied it good roads

ing two - thirds o f the county has less than half the mileage which it should have in order that farmers may get

eir products to market as economically as possible . Good roads are the first requirement for successful farming and f the best indication o the prosperity of an agricultural region . In order that Rutherford County may develop its natural resources to their

of 400 full possibilities it will be necessary , first all , to build at least

o f fi rst - es more class roads , and to repair and keep in repair

pikes it already has .

Clim at e

o f on The climate Rutherford County is the whole agreeable , but summers are too warm to be conducive to systematic habits o f in The first frost comes about the middle of October and the

s o w i s e in April , that the gro ing season long enough to

of The - the ripening cotton . reddish brown soil absorbs heat during the day and radiates it at night , so that in July and August m both days and nights are war . fi 50 . The annual rainfall is about inches This amount is suf cient ,

o f if evenly distributed throughout the year , to supply the needs all D f crops . estructive winds are o rare occurrence . The hills which nearly surround the county protect it from high winds . Gentle winds r blow through the valley o f Stones Rive nearly every day . 8 GEOLOGY OF RU T H E RFORD COUNT Y

E conomi c R es our ces The soil is by far the most val uable natural resource in the co

w i s u - o f It works ell and fertile , yet it does not prod ce one half it sho uld . With proper methods of farming the soil could be to produce easily twice as much per acre as it now does .

The assessed value o f the county outside of Murfrees boro is $6 000 an average of $ 1 5 an acre for the acres i

u w o f county . This estimate incl des the to n property outside f re sb r u e o o and also personal property . Making these ded ction probable that the assessed value of the land alone would be

1 0 o f $ an acre for the whole county . The land the central p

w o r u u e the county is , however , orth three fo r times as m ch p

u u as that s rro nding it . By the application of scientific farming u u ods , and good free roads , the assessable val ation co ld in five

" time be raised to double the present am ountfi Next in importance to the soil as a natural asset comes the with which the county is over suppliedf There is an ab undan rock suitable for making roads , for cement , and also for limin

u i i soil to increase its prod ctiv ty . The benefit to be der ve use of ground limestone as a corrector Of soil acidity is ning to be recognized by the farmers .

The forests o f red cedar which thrive so well on the glades l being exploited to their full capacity . Many areas which wil r

o f u e nothing else val e have been robbed Of their c dars , and attempt should be made to reforest these glades and other land . A large income could be derived from the growing forests at a small outlay o f time and money . The potential water power of Rutherford County is much g than that now being utilized by the small grist mills alon of Stones River . The narrow gorge through which t furnishes favorable conditions for the b uilding

viz . " 1 for the storage of water , ( ) short dams , therefor 2 w w pense , and ( ) the back ater ould not Spread o ut

. e o f able land The narrow gorge has the disadvantage , how ver , quiring high dams in order to hold enough water t o last dur

* M r . A . V . ou an C e Tax S a s c an of th e S a e B oar O f E ualizat L th , hi f t ti ti i t t d q states that in 1 91 8 th e tot al ass ess m ent of all realty was while th e total valuation will b e O n p ers onal p rop erty th e v 1 91 8 a w s while in 1 920 it will b e app roximat ely ECONOM IC RESOURCES

w w . season . The potential water po er of the country is unkno n b little of this power is now being developed . The power could e i ’ s W . to generate electricity, as now being done at alter Hill he natural and other resources will be discussed in detail in a

ate chapter . 1 0 G E OLOGY OF RU T H E RFORD COUN T Y

CHAPTE R I I .

TOPOGRAPHIC D E SCRIPTION

THE R IM O F HILLS

The county is nearly surrounded by hills , which are the remna o f the Highland Rim . The county includes very little of the w Rim proper , but it has many hills hich are as high as the

o f th several ridges , especially in the southeastern corner which are remnants of the Rim ; The largest remnant is w o r four miles long ith several branches , about three

o f is B ig Springs . The top this ridge the highest eleva

' 1 3 52 c ounty, , feet , and it is also the highest point in the St o f the Cumberland Plateau , excepting Short Mountain in

County .

The tops O f most o f the hills and ridges along which the county r w uns bet een Cannon , Coffee , and Bedford counties , and Ruther from the Bradyville pike south and west to the Shelbyville pike,

o f w at an elevation of about feet . The belt hills bet een Bradyville and Manchester pikes is about four miles wide

w V - i valleys are narro and shaped and the hills are steep , having a r se

5 0 w O f about 0 feet in the last mile to their tops . A lo er belt hills alo the county line from the Manchester pike to the Shelbyville pike

one two w . u much narrower , being from to miles ide They are q s 3 00 500 teep , rising from to feet in a mile at places .

The tributaries o f Stones River have cut back into the Highl w w Rim , making many narro hollo s , and at Hoovers Gap the river c ut nearly through the divide between Bedford and Rutherford ties . This divide, as well as all the other hills in the county, is ly a remnant o f the highland which once extended over the

Central Basin .

From the Shelbyvi lle pike around to the Franklin road the line runs over fairly level country . The former highland in the

o f h as west corner the county been reduced to isolated hills . M A P o r R U T H E R F O R D C O U N T Y

S C A L E

TE NN E S S E E GE O L O GI C A L S U RV E Y

W LB U R E O N STATE GEOLOG ST I A N LS , I 1 9 I9

erf or Coun s ow n s o ra c R e ons . of Ruth d ty, h i g Phy i g phi gi 1 2 G E OLOGY OF RU T H E RFORD COUNT Y

Between Williamson and Rutherford counties , north of the

o f w lin road , is a range of high hills , the highest ones hich re elevation comparable to the highest ones in the southeastern umn o f u e . S the co nty, that is , about f et Signal Hill and are capped with the same formation as that found on the hill

o f ing the Plateau of the Barrens , the Ft . Payne chert . The top ners Knob is about 550 feet above the more level country to the

There are no high hills between D avi dson and Rutherford c o u

r u nor in the northern corner , but the e are numero s small , round The eastern side o f the county includes several ranges of high

o f which are prolongations o f the Highland Rim . Many

o f the border adj oining Wilson County, north Lasca bench or terrace near the top . These hills are capped limestone ( Cannon ) , below which is a sandy limestone ( H

so which weathers readily and produces a fertile , tillable

b ed o f the sandy rock is another solid limestone ( Carters) , resistant to weathering . The sandy rock weathers faster

o r s limestones above and below , and makes the more les level or terrace around the hill .

i i s r o u h The eastern third of the county quite g , the hills for the

" part being in long ridges with a northwesterly direction . The

w a n . bet een the ridges are wide d fairly level . The hills in the easter h c’ t ird of the county oc upy something like 70 per cent of this area .

T HE CENT R AL P LAIN

o f o ne - The central and western parts the county , about half the to

r a ea , may be classed as level or rolling. These parts , here called v u Central Plain , ha e an elevation o f abo t 500 feet in the corner and 700 feet in the southern and western ends of the co The larger portion of the plain has an average elevation of 600 The lowest point ( 475 feet ) is where Stones River leaves the co The level part of the county is essentially a peneplain plain ) . It had been reduced in the Pleistocene or Glacial perio u w low as r nning ater would make it . Scattered about over the tral Plain are isolated b ills or small ridges ( monadnocks) Cons o us examples of these are the Marshall Knobs , north of Rucker

field Knobs , Pinnacle Knob , Blackman Hills

e Eagl ville . GLADES

D R AINAGE The county is drained almost wholly by Stones River and its trib

60 u o f About sq are miles , north and east Eagleville , are

ed by the headwaters o f Harpeth River . The water which falls

th of o f o f 8 the hills south Eagleville , an area about square miles ,

u ains out through one of the tributaries of D ck River .

GLAD E S

n tio n — D efi i . The more or less flat areas of bare rock , or rocky places

f o r ich are valuable only pasture or raising timber , are known in “ ” “ ” “ sse e as glades . The word glade originally meant an open ” ce in a wood ; next the word was applied to the cause of the open

now space , in this case rock, and it is applied to any rocky place whether

r trees still surround it o have been removed .

KIND OF GLADES

There are two main kinds o f glades in Rutherford County " ( 1 ) the

of ical red cedar glade , which is a flat or hilly region platy , thin

o r w limestone (Lebanon rarely Pierce) , here only red cedars

ckl w 2 - w y pears will gro ; ( ) the massive rock glades , or hard ood

on which grow , or have grown , oak , hickory, and locust , but only

dar e s . Cedar glades ( from which the Lebanon or Glade limestone

5 o f name ) occupy a large proportion the area of the county ,

- u o ne o f . sq are miles , or over fourth the total area The

u third of the co nty is characterized by the cedar glades . i irregular b and from two to ten miles wide nearly sur ' w . w county These glades , hich are Often pastured , gro

u o f q antities red cedar trees . These are the lowest priced lands in

ount . u 1 1 0 y They are val ed at from $ to $ an acre , depending

the amount and quality of timber remaining upon them . Some

' "

there are a few acres which can be tilled , but the soil is so shallow

crop cannot stand even a short drought .

dwoo d o r massive - rock glades may be considered for con

' two " w consist of types ( a ) flat areas of solid , bare rock ith

s o r on which nothing can grow , and ( b ) areas of ma sive

" with numerous j oints o r vertical cracks partially filled with 1 4 GEOLOGY OF RU T H E RFORD COUNTY

soil . A good example of the first kind is the center of the Sta

the miles northeast o f Murfreesboro . Abundant examples of second kind o f massive - rock glades may be seen within a mile or two f o f . o Murfreesboro , in any direction Hardly a square mile the f Central Plain is without a patch o this kind o f glade . w The rock of the hard ood glades is usually Ridley limestone , but

o r ra may be Murfreesboro limestone , Carters limestone , more

s s th Cannon limestone . All of the e lime tones are much alike in ical and chemical characters and under Similar circumstances prod similar glades .

Grasses and various kinds of trees , mainly white oak , grow in joints betwee n the flat blocks O f limestone . There are all gradations tween the proportions of rock and soil of the hardwood glades " ( 1 ) perfectly bare rock without j oints ; enough betwee n blocks for trees to grow ( numerous the Franklin road ) ( 3 ) areas o f about equal proporti soil ; ( 4) glades where the soil occupies four o r five tim surface as the rock does ; and ( 5 ) areas which can be farmed where numerous knobs or masses o f rock are exposed over the field .

ORIGIN O F GLADES

u Glades originate by s perficial sol ution and erosion . The pro m w operates so e hat differently o n different kinds of rock . The Lebanon and Pierce formations are made up of layers

s thin , broken slabs of dense limestone , sep arated by thin film of sh These limestones weather rapidly by freezing and thawing and solution o f rainwater and groundwater Charged with carbon

Weathering is mainly at and near the surface , and the solu of u 0 the rock is dissolved and carried away . The small amo nt

so ble material , mainly clay , is fine and impalpable that it away by each rain , or by the heavier rains , as fast as it is p w broken slabs shed ater like Shingles , so

u r e eate numero s j oints and cracks . The p rains during the winter are sufficient to keep the rock practically from soil where there is Slope enough to allow the water to run

When the glades have bec ome so nearly level that most of rainwater runs into the rock and the remainder flows off very slo t hen the residual C lay accumulates and forms soil . After the

1 6 G E O L OGY OF RU T H E RFORD COUNT Y

O f on the top of the solution . When some the scum is heated and

off all the Oily matter driven , there is left a film of white clay . This experiment shows that this oily matter causes some o f the residual clay to be buoyed up and therefore carried off by rainwater nearly as fast as it is produced . In this section porous limestones and those containing bituminous matter rarely form glades . STAGES IN THE TO P OGRAP HIC HISTORY

CHAPTE R I I I .

TOPOGRAPHIC HISTORY ST AGE S IN THE T OP O GR APHIC H IST ORY

In tracing the development o f the present physiographic features

o f r " topography the county, fou stages the hilly rim , the central

e isolated hills , and drainage may be recognized from featur s

s . " ent in Rutherford County, viz 1 . The Highland Rim peneplain stage ( end of the Eocene) 2 r " . High Ter ace Gravel stage (end Of the Pliocene ) 3 . The Central Basin peneplain stage (middle Pleistocene) 4 The Recent Uplift ( late Pleistocene and recent)

T H E H I GH L A N D R IM P E NE P L A I N S TA GE

The elevated plain o r plateau which constitutes the Highland Rim Middle Tennessee is the remnant o f the plain which once extended D across the Central Basin . uring the Cretaceous and Eocene

" the agents o f weathering and erosion had worn down the rocks of Middle Tennessee t o a featureles s plain which ex rom about the present location of the Tennessee River to a line

i s to through Franklin , Warren , and Overton counties , that ,

o f D o f the Cumberland Plateau . uring that time the Gulf extended up the Mississippi Valley as far north as southern covering all of western Tennessee to within ten miles of the

The sediments , mud and sand , resulting from the dis

o f 700 800 o f and decay or feet sandstones , shales , and were carried by the rivers to the extended Gulf and there

end o f the Eocene the Highland Rim peneplain varied from 400 500 about where the Mississippi River now is , to or

se a level along the western front of the Cumberland Plateau . and Rim peneplain was from to feet lower in

u not ord Co nty than it is now . This ancient plain is preserved county except on the tops o f the highest hills bordering the It may be seen at the tOp of the high hills east and south

Milton ( elevation to feet ) , the top of the Ready T GE OLOGY OF RU T H E RFORD COUN Y STAGES IN THE TO P OGRAPHIC HISTORY

t Pilot Knob feet) , Murray Hill fee ) and the of the highest hills on and near the county line from the Brady

pike to the Shelbyville pike . The highest ridges in this locality

elevation of feet . These are the n Middle Tennessee on what remains o f

The Plateau of the Barrens , as well as d o e . pp hills bordering it , are the remnants of this peneplain not probable that any hills in the western side o f the county

o f f - this peneplain , since none them are lat topped , but several are nearly high enough and represent approximately the loca f i the peneplain . Pinnacle Knob , the Eagleville h lls , Sumners

o f e and Signal Hill , all have an elevation about fe t , is not far from the present elevation of the peneplain elsewhere

county .

II s - of , is an ideal cro s section the Highland Rim pene

o f the Eocene period . Rutherford County at that time

200 o r 3 00 sea f feet above level , and the surface features were the same as those now seen on the

There had been some folding o f the strata in the center o f the

State before the Eocene period , in the Paleozoic era , and especially at

o f a the end th t era , when the Appalachian Mountains were folded up .

0 e era there was some oscillation , which reach d

tac ous e period . The Cretaceous peneplain the Cumberland Plateau (possibly to after t h e Cretaceous uplift) t o the Tenness ee There are no remnants o f the Cretaceous in in Rutherford County and no deposits which can be assigned

period . rivers had cut down some distance into the rocks below the land Plateau peneplain during the late Cretaceous while middle

b el n see were g elevated , but it is highly improbable

n as far as the Highland Rim . When the rocks 0 the latter peneplain during the Eocene any Cretaceous f were also removed . The thickness o rock removed dur etace ous and Eocene periods varied from nothing in the Tennessee River to 900 feet along the foot o f the Cum id elevation took place at the end o f greatest erosion took place during the 20 GE OLOGY OF RU T H E RFORD COUNT Y

w Eocene . This is also sho n by the greater thickness of Eocene depo in western Tennessee . D uring the long Cretaceous and Eocene periods there had b sufficient time f o r the agents o f erosion to cut down thro ugh the s istant cherty limestone and sandstone o f the Ft . Payne “ u the nderlying less resistant Chattanooga ( black Shale,

w th e even do n into Trenton limestone beneath it , at the

u . dome in R therford , Wilson , and Marshall counties The high , isolated hills still remaining on the Highland Rim peneplain

o f w the end of the Eocene period , an example hich is Short Mounta

Cumb rla in Cannon County . This mountain is a remnant of the e

Plateau . At the beginning of the Eocene most of western Tennessee D sea w . below level , as Sho n by the deposits uring the Eocene Cumberland River and its tributaries no doubt had approximately h same courses they now have , but t ey meandered about over the

l . ture ess plain .

H I GH T E R RA CE G R A V E L S T A GE

At the close o f the Eocene period there was a gradual elevation

b ut was Middle and West Tennessee , the rate and amount of rise n

axI S everywhere the same . The rate o f rise was greatest along the

b ut was w the present Central Basin , slo enough to all

D r land , uck , and Elk rivers to maintain thei courses The elevation continued without interruption during th

w o f wh Miocene periods and into the Pliocene , to ard the end the elevation ceased for a considerable time , and there may have 50 a depression of about feet . There are no recognizable deposits of either Oligocene or Mi

r age in Ruthe ford County , nor have any deposits of these ages w recognized any here in Tennessee . This may be interpreted to that all the streams in the State were actively eroding during

, u w as w periods and the res lting sediment carried do n into , the Mississippi Valley and there deposited in the extended Gulf of M The Gulf then covered the southern portion o f the states 0

i o f and Mississippi , and depos ts Oligocene and Miocene age have recognized there . 2 . o f O f Fig , plate II , is a diagram the possible topography M and West Tennessee during the Miocene period . It is not a de STAGES IN THE TOPOGRAPHIC HISTORY

but is merely intermediate between the Eocene and the Pliocene It is introduced to Show the differential rise of the Central

region . ward the end of the Pliocene period the rivers of the Central

w t o 200 sea region had cut do n about feet above level , which

they could out . Then then began to meander . The

S now River had a high gradient , as they have , carried sand and gravel from near the tops of the hills down

a nd in ome distance dropped them , because the water had

ac cum u velocity to transport them further . These gravels a depth of 50 o r 60 feet in the valley o f the east fork of o doubt had a similar thickness at other places ls surrounding the county were then 700 to 800

ve sea level .

or o f hill terrace gravel is made up rounded , waterworn

of chert and quartzite , from the size of a marble up to three

s inches in diameter . There is also considerable and and fine

not e ce The mass is consolidated , but is sometim s slightly m nt w e ed ith yellow iron oxide . This gravel occupies an intermediate position between the Highland Rim peneplain and the present t opo gr a phy . Similar deposits occur at corresponding elevations along the

. f Cumberland River These gravels are probably o Plio cene age . The high gravels may be seen in Rutherford County on a hill five ast of Lavergne ( elevation of the t op about 580 fee t) ;

0 of of t o 700 miles southeast Walter Hill ( elevation p , and on the tops Of several hills along the river south of Las

68 on hillS ( elevation 0 to 700 fee t) . There are no gravels the

the valley o f the west of Stones River . “fork Most of the pebbles Of chert in these gravels were derived from

o f . e heavy beds chert at the base of the Ft Payne formation , which “ on o f of j ust above the black Shale , the brows the hills the Highland

It seems quite probable that the quartz and quartzite boulders ,

of e make up a large part the terrace gravels , were deriv d from wer Pennsylvanian (Lee) conglomerate which caps the western

was Cumberland Plateau . The Lee conglomerate weathered

w a of do n into gravel and sand , over the are the Central w west ard , during the Cretaceous peneplanation period , t ’ d from the Permian o the early Cretaceous . Since that een worked over by water many times and most 22 GE OLOGY OF RUTH E RFORD COUNT Y

u o f them have been gro nd into sand and carried down the rivers . The chert and quartzite gravels are s o resistant to erosion and decay that s ome o f them remain in the old river channels and even in the present w h river b eds . These hard gravels ere also the tools by whic the streams were able to Sink their beds into the hard Trenton and Stones l River imestones . 3 1 1 m . o f Fig , plate , is a diagra showing the topography Middle

Tennessee at the end o f the Pliocene . It also shows the possible history of e w West Tenness e , here there had been considerable erosion since w the Cretaceous and Eocene deposits ere laid down . The Highland Rim peneplain was probably cut down some 200 feet on the west of the Tennessee River during the Pliocene , and the terrace gravel , derived from the Mississippian and Pennsylvanian rocks to the east w w ward , was laid do n by meandering streams over the ne er peneplain . N The ashville structure dome , the Central Basin region , 3 w 500 600 th in Fig . to have risen bet een and feet since 600 w the Eocene, because the high gravels are about feet lo er 200 the Highland Rim , which could . not have been much over

f umb rl above sea level at the end o the Eocene period . The C e

Plateau is s u pposed to have risen 200 feet and West Tennessee feet during the same time .

T H E CE NT R A L B A S IN P E NE P L A I N S TA G E ( M ID D L E P L E I S T O CE NE )

of r 1 s1 n of At the end the Pliocene the g the land was resumed ,

o f continued till about the middle the Pleistocene period , when D was another pause . uring this time the Nashville about 300 feet and the western streams o f the Central Basin cut down to an avera 400 feet , which was about base level at that distance by water the sea . The Gulf embayment had retreated from its former p o

e as far north as Tenness e to somewhere near its present location . streams then Cut down the divides between valleys and reduced the o f l Stones River to a penep ain . Most of the Central B its present dimensions and topography at that time . The ea Stones River cut down about 1 00 feet below the top o f gravels . It i s a remarkable fact that there are V ery f ew alluvial d

Pleistocene age in the Stones River basin . There is no

24 GE OLOGY OF RU T H E RFORD COUNT Y

entrenched itself to varying depths , depending on the distance

f - u w Pleist oc the Cumberland . The amount o down c tting belo the 40 ff Central Basin peneplain is about feet at Je erson , Walter 3 0 20 Bettys Ford , feet at Lascassas , feet at Halls Hill , a

o f amounts farther up the river . The entrenching the smalle is less than it is in Stones River and fades out a few miles from river . There is very little alluvium along any of the streams except

th e w was along inside of the bends , here it deposited during h

. water The beds of all ,the streams of the county have been o f debris except in a few places where there is limestone

e chert derived from the limestone , or in some cas s , from the formation . The topographic history of the entire Central Basin is as that outlined above for Rutherford County . The periods of e

w b ut o f and periods of rest ere the same , the amount rise and

w as of erosion varied at different places . The doming less in both to the north and to the south of Rutherford County and vations of the various peneplains and river levels were not t w every here in the Central Basin , but the stages in the history results attained are strictly analogous to those for Rutherford 5 w Fig . , plate II , is a diagrammatic profile across estern and

sh o wm . d dle Tennessee g the topography at the present time The . i line is the reconstructed Highland Rim peneplain . The profile s d as accurately as the data available and the scale will allow . The reason f or the excavation of the Central Basin in the top 0

m of dome is that the strea s cut through the hard , insoluble chert

Ft . Payne formation during the Eocene period at the place where w strata ere already slightly domed , and when further rise took the streams immediately began cutting into the dense but soluble m w w wh stones below . The strea s ere also shod ith chert debris

so s o much harder than the limestone , that both abrasion and a on b ut cted the limestones , weathering and erosion took place

s' o f rapidly in the siliciou rocks of the Ft . Payne formation the Hi land Rim .

T HE SH AP E O F T HE CENT R AL B ASIN

Many people have ob served that the Central Basin is similar to

e lake basin , and some p ople have the erroneous idea that it is K - R CAVES , SIN HOLES AND UNDERGROUND D AINAGE

e bed o f a drained There is no reason f o r thinking that

c on Central Basin was ever a lake except its basin shape . On the are many reasons why it never could have been a lake

no evidence that all four rivers , the Cumberland , Harpeth ,

lk o ne r , which drain the basin , or even any of them , has eve med so as to cover the Central Basin o r any part o f it with 2 w ( ) there are no beach terraces around the basin , hich are a cuouS feature o f most extinct lakes ; ( 3 ) there are no delta ts in the basin where the streams which fed the supposed lake 4 have emptied ; ( ) there are no lake deposits , such as marl ,

or w a e black soil , which are al ays left behind when lak is

' 5 w f re shwater sh ells ( ) there are no deposits ith remains of , other animals which abound in lakes ; ( 6) there are no remains o r marsh plants ; ( 7 ) there is no lake in the world occupying a position in an erosion basin on the top of a structural dome the basin was formed by erosion and the rocks which once w have been eroded and carried a ay in solution by the rivers ,

ivers were there before the basin .

E INK -H AND ND R R ND D R INAGE CAV S , S O LE S , U E G OU A

The rocks under the Highland Rim and o ut o f which the Cen tral

'

o f . asin was carved , consist almost entirely dense , brittle limestone are broken every f e w feet or traversed by two sets o f j oints

' an at parallel d right angles to the longer axis of the dome .

o f ts are largely responsible for the formation the basin , for the rocks to be weathered vertically a considerable dis

the surface as well as at the surface . After each successive te r would seek lower levels through the j oints and cracks

as well as over the surface and down the valleys .

S away the limestone fastest where j oints cross , nsiderab le size has been formed by solution it is

. th e o f sink Sinks develop in shape a funnel , nnels collec t more rapid solution at the bottom Of the funnel In the j oints and bedding planes where the water escapes . nderground channels are made which sometimes carry c on

l T nn - eo . e . 1 869 . 1 001 03 Sa or and K eb r m ew E e . eo G , , pp ; ff d ill , l G l .

p . 23 . 26 GE OLOGY OF RU T HERFORD COUN T Y

r b le w s ide a volumes of water , and hen large enough , are called The underground channels always emerge along some stream an w 1 are called springs , but the water hich flows from them is surface water and likely to b e contaminated . These springs are

i w h s like the open ng of a tile drain , into the upper end of hic a stream runs . Since the Central Basin peneplain was formed and after the recent

U o f - plift , thousands sink holes have been developed over the central

f o f plain o Rutherford County , and much the water which falls as rain is carried down to the rivers and larger streams through these 20 underground channels . The sinks are not ordinarily over feet deep

of a sm all and most them have , diameter , since the time during which

o f they have been forming is comparatively short . Some the larger ones were probably developed during the Pleistocene . Among these m ay be mentioned a 60- foot sink and cave one mile northwest o 1 00 trell , which is feet above Cripple Creek and has an elevation about 700 feet .

Another o f the older Sink - holes is the one into which the creek fr

Fox Camp Spring runs . Thi s Sink was developed in the bottom 0 small valley where the water found a channel along the cracks in rock . After running a mile and a half underground fl emerges at Sand Spring . The water which ows from

f rom ' Fox does not all come Camp Spring , eral other underground streams and Sinks before it emerges . Part of the Sand S ment as it comes through the body of the rock and but most of it comes directly from the creek leading n Spring and is surface water , as show by the fact that w n rains Sa d Spring becomes muddy .

The water fl owing from Fo x Camp Spring is gathered s l numerous sink in the neighborhood of Di lton . The und channels leading from the sinks are small and the water fr

the o f seeps through cracks the rock rather than runs . of the limestone i s going on and underground " channels are being

o u solved and eroded t . Th e water from this spring has a milky blue color .

" A more obvious example o f subterranean drainage is a stream 0 o f w mile northeast Florence , near Miles Ford , where the ater may K - AND R 27 CAVES, SIN HOLES UNDERGROUND D AINAGE

running past the bottom of several sinks and under the road and In ly emptying into the river . rainy weather this stream is quite

alf mile due east of Marshall Knobs and on the river bank a

urts up from a crack in th e rock . The water is warm in the ime and probably comes from a sink one -third o f a mile far

D o f from ouble Springs , three miles east Murfreesboro ,

nk - of , later appearing in several steep sided sinks south After running straight north it reappears as a spring

1 Creek .

eesb o ro , near Kings Hill , a large spring

e w into Overall Cre k . The ater which comes from this spring

red from numerous Sink holes south of Kings Hill . After

w - o f do n Overall Creek three quarters a mile the water , during It ' all disappears down a crack in the rocks . appears i D th ’ m ll m le farther down stream . uring wet weather e s a

channel cannot carry all the water , and then it runs r c eek . This is an excellent example to Show f stage in the development o sinks and underground streams . a few hundred years the underground channel will be large enough

" to car r one we _ y the water at all times , as the bet en Sand Spring and

now Fox Camp Spring does . These examples are only a few o f the hundreds which may be seen

enci sed m in Rutherford County . The underground drainage and ean

w two o f t . ders sho things grea interest First , that the land has been recently elevated , and second , the method by which most of the rocks

e h ave b en , , of the Central Basin d removed that is by solution both at the surface and underground . The j oints and cracks were produced by

of of N D the warping the rock during the rise the ashville ome , which took place for the most part during the Permian , Cretaceous and Ter tiar y periods . 2 8 GE OLOGY OF RU T H E RFORD COUNT Y

I CHAPTE R V .

D E S CRIPTIV E GE OLOGY H IST O R I CAL R EV IE W

Rutherford County is the type locality of the Stones River group ,

81 r 1 851 . . . D . . . which was named by J M Safford in (Am Jour Sci Arts ,

was 2n r . . d se . , vol xii , p The name taken from Stones River , a long which the best and most complete section of the Stones River

u 1 869 f u i o f gro p may be seen . In Sa ford p blished descr ptions the formations occurring in Rutherford County ( Geol . Tenn . , p . but “ ” a bandoned the name Stones River , thinking that the group was s trictly equivalent to the “ t he o r . name to Trenton , Lebanon Winchell and Ulrich the true age and position of the Stones River group (Geol .

1 897 u iii , pt . ii , p . xc , ) and res rrected the name but placed

o f in the Black River . The descriptions and figures many S tones River fossils from the type locality are published in sota report mentioned .

f w 1 900 u e Sa ford and Killebre , in , p blished a resume of the g

. W of the State (Elem Geol . Tenn . , p . in hich they included d r o f esc iptions the rocks found in Rutherford County, and they

in which i s fined the name Stones River in the sense . it now Hayes and Ulrich described the rocks of the Col umbia quadrangle

S . . S . 95 1 903 w u o f G , folio , ) hich are very m ch like those Ruther

u b ut o f t Co nty, the strata the wo areas differ in detail . They give the range o f a considerable number of fossils which for the identification and correlation of the strata . They a o f the fossils of the Murfreesboro and Pierce limestones , strat

u u u o tcrop only in R therford County . In this p blication the Carter l was imestone again placed in the Stones River group .

ST R AT IGR APHY AND AR EAL D IST R IB UT I ON The sedimentary or stratified rocks of the earth ’s crust are divid and subdivided into units according to the age in which they f one ormed and to their position above another . STRATIGRAPHY AND AREAL DISTRIBUTION

RO CKS N O T E" POSED A T THE S URFACE

The knowledge o f the rocks underlying a region and not outcrop

wh ere 1 y in that region is obtained in two ways , ( ) directly , from

2 o r deep wells , and ( ) indirectly , by inference from u w o tcropping in adj acent regions . Several deep ells have

ed in Rutherford County, but unfortunately the records , if

o f th r ou h l in kept , the rocks passed g drilling the wells are

available for study . Beneath the Stones River rocks of the Sequatchie Valley and of the lle o f y East Tennessee occur several thousand feet of dolomite , lime ne , Shale and sandstone , the Knox group . In the Wells Creek basin w ones River rocks are missing and the Lo ville , corresponding to

arters , lies unconformably on the Wells chert , and the Wells

o n n w lies the Knox dolomite . These are the regio s from hich

w o ur dra inferences .

king into consideration the succession o f strata below the Stones

group in other regions , and their thickness , it is probable that the beneath the surface o f this county are approximately as given

- t o w . following table , from the p do n to the pre Cambrian floor are the rocks which would probably be encountered if a well rilled on Stones River at the Nashville pike " dovi ci an

Stones River

M ur rees oro mes one une os e ckness unknown os I . f b li t , xp d thi , p sibly

2 ch r oss res en ro ab e h ckness . W e s e ll t p ibly p t , p b l t i Knox Group ( Knox D olomi te of S affor d)

ma nes an and ar aceous 3 . U er Kno C e u e ec pp x ( h p lt p ) , g i gill 4 M e Kno Co er R e ra o om e er c er . iddl x ( pp idg ) , g y d l it , v y h ty 5 Low er Kno ue t o ra o om t e and m e s o ne er e . x , bl g y d l i li t , v y littl ch er t C amb rian 6 Conosau a S a e Kno S a e Sa or s a es and me . g h l , x h l ( ff d) h l li st ones 7 Rom and Kno an s on Sa or ca c areous s an s ones . e S e x d t ( ff d ) , l d t and shal es ; m ay b e ab s ent 30 GEOLOGY O F RUTHERF ORD COUNTY

S e r ie s f o r m at i o ns

F t P a yn e ( T ull a h o m a )

U n c o n f o r m i ty C h a tt a n o og a. U n c o nf or m i ty

L e i p e r s 0- 1 00

U n c o nf or m i ty

0- 3 00 C a n no n 2 0

0- 3 0

7 0 8 0 H e r m i t ag e

U n c on f o r m i ty

- 8 5 C a r t e r s 6 5

U n c on f o r m i ty

L e b a n on 8 0- 1 2 0

R i d l e y

I fie r c e 2 3 - 2 8

M ur fr e e s b or o

3 2 G E OLOGY OF RU T H E RFORD COUNTY

R O CK S E " P OS E D A T THE S UR F A CE

The rocks exposed at the surface in Rutherford County all belo n t o the Ordovician and Mississippia systems , with the exception

o r . hill gravels and alluvium stream wash The sequence , names

of subdivisions , and general character the strata are shown

of columnar section , Plate III . The descriptions the various strat

of c eeds in the order deposition , beginning with the oldest , the Or

V i cian system . O R D OV I C IA N S Y S T E M The Ordovician strata which may be seen in Rutherford County enumerated in the following table , in their natural order

U nconformity Cinc innati an seri es M aysville group Leip ers formation Unconformity M oh awki an s eri es Tr enton group Cannon lim estone Bigby limes tone Hermitage formati on U nconformity Black River group Cart ers limestone U nconformity Chazyan s eri es Stones River group Leb anon lim estone Ridley limestone Pi erc e limestone

M ur rees oro m es one b as e not e os e f b li t , xp d

STONE S RIVER GROU P

The Stones River group was named by Safford in 1 851 and

i a i s nally ncluded the Carters limestone . The C rters limestone

u o f considered as the eq ivalent of the Lowville Black River age , the Stones River includes the lower four formations only .

M urfreesb oro lim est one

Nam e i i n — ff d th e Murf reesb e and d fin t o . Sa ord originally calle limestone “Central ” limestone “for the reason that it is thus in 259 o f 1 869 . the very center the State ( Geol . Tenn . , , p ) STRATIGRAPHY AND AREAL DISTRIBUTION

w Killebre changed the name to Murfreesboro limestone , because rf reesb or o is near the center of a circular area o f an outcrop o f ”

1 900 . No formation ( Elem . Geol . Tenn . , , p definite spot

designated as the type locality . Sboro limestone being the lowest in the county outcrops only re local domes and where the upper rocks have been

cut through by the river . The Murfreesboro limestone in y a circular area from twelve to fifteen miles diameter ,

Murfreesboro is near the center , as stated by Safford and

d and Killebrew , but it does outcrop at several places within Safford confused the Ridley limestone with the Mur f rees

o on of two , account the great similarity of the formations and failure to take into consideration the small domes or wobbles in

strata .

The Murfreesboro limes tone Occupies a surface area of about miles and it does not outcrop anywhere in the Central

o f Rutherford County . It outcrops at several places

o f o f forks Stones River , and within the city limits The best exposures are at the following places " along

at N one of . the ashville pike , mile west Walter Hill ,

theast of N . the ational Cemetery , and at Sand Spring — Since th e base of the formation is net exposed any

the county its entire thickness can not be determ ined . Its

one exposed thickness is seventy feet at three places , viz . ,

le one - M cFaddenS west of Walter Hill , half mile up the river from

Ford , and at Sand Spring

, Character — . The Murfreesboro formation consists of heavy beds

h - o r of dark bluis gray drab , dense, brittle limestone . The beds vary from six inches to four feet in thickness and are sometimes separated

of r an n thin partings shale o sand . The stone emits Oily odor upo

surface layers are sometimes very cherty, especially

here solution is rapidly going on . The chert is gen

black in color and nonfossiliferous , but after long

o r is white rusty red , and fossils can then sometimes be

In ert considerable abundance . Fossils other than fucoids

in the limestone . The fucoids , which are abundant , are and consist o f granular cal 34 GE OLOGY OF RUTH E RFORD COUNTY

cite , which looks like sand and which weathers faster than the more

- o f w . dense body the rock , giving the rock a orm eaten appearance

The presence o f chert is wholly a surface phenomenon . The chert is formed from silica taken into solution from the limes tone during weathering and redeposited in the form of nodules or plates . Fossils are sometimes the nuclei around which the chert is deposited . Most of the fossils which can be obtained from the Mur f re

s ilicifi ed are and partially embedded in chert . The outcrops o f Murfree sboro limestone present different

ances o f , depending largely on the stage in the process wea The following stages may be recognized " ( 1 ) When fresh it

fi ne - drab , exceedingly grained and very dense , but con

not . Fossils , fucoids and clay seas recognizable It is b

one - 2 quarry half mile south o f the courthouse . ( ) Wh en w - eathered it is light bluish gray , with greenish patches and

giving the rounded surfaces a mottled appearance . It is best n 3 Stones River o the Nashville pike . ( ) When further w the surface is full of round holes one - fourth inch in

and ( fucoids) , the bedding planes look like clay seams

z ontal o f to seams chert , giving the rock the appear

- 1 thin bedded . It is best See n at the city waterworks . ( )

weathered the clayey seams have broken down ,

- h plates full o f blue black chert . It is best seen w

ox F Camp Spring disappears . This stage looks like 5 without the fossils . ( ) On further weathering most 0

are gone and large fragments of chert are strewn about . The

o f black inside and white outside , and sometimes it is full

al ere lla 6 mainly gastropods and S t . ( ) The last stage is rep

s - w o f by reddi h bro n soil containing small blocks white chert .

S ection of th e M urfrees b oro Limes tone on S t ones River j us t no rth of the Nas ville pike "

- 3 . ue or o e co ore ens e mas s e non oss erous me Light bl d v l d , d , iv , f ilif li

s one in a ers 2 t o 4 nc es ck s e ara e n e ow s t , l y i h thi , p t d by thi , y ll i h ,

- m n M a mum k n ar n s C er and uco s com o . s andy loo i g p ti g . h t f id xi thickness 40 rods north of b ridge

ra s - ue ne am na e ens e fi ne - ra ne m e s one o n e G yi h bl , fi ly l i t d , d , g i d li t , j i t d

n o ea ers as er an r ocks a o e and e ow every i ch or tw ; w th f t th b v b l , 1 /2 t 0 1 STRA TIGRAPHY AND AREAL DISTRIBUTION

M ass e dense drab non oss l erous l mes one o n s 6 t o 8 ee iv , , , f i if i t , j i t f t ap art ; ch ert and fucoids common ; thi ckness at b ridg e from wat er level 20 Perhaps the most interesting section o f the Murf reesboro forma

on s on is Bradleys Creek at La cassas . It is as follows

- 3 . M ass e ens e rab l m es one w h b ue t o awn co ore ch er at iv , d , d i t , it l f l d t th e surface

ens e b ue c er m es one con a n n S alt erella S tromatoceri um D , l , h ty li t , t i i g ,

and O rtho ceras

San lam na ed s un- cracke r le - marke l mes one ch er dy, i t , d , ipp d i t ; t nodul es laminat e d s ame as limestone

This locality is the only place in the county where the Mur f rees

u - t boro formation is sandy or laminated and s n cracked . It shows tha the o r h seashore was near Lascassas at that time , possibly that t ere

o f d been a slight doming , the strata at this place during the close

the Murfreesboro stage .

Com osition — f p . Although the f resh Mur reesboro limestone is dark

" - e . color , when it is burn d it makes a snow white quicklime The rk color is due to bituminous material which is driven off in the

The chemical analysis is given in Chapter VII.

rf reesb or o s limestone is usually unfos iliferous , fi ilici ed fossils are abun dant in the weathered chert . localities f or collecting fossils are " ( 1 ) At the bridge over Stones River on the Nashville pike ; ( 2 ) in the soil along the street in f ront of the Central Tennessee Normal School ; ( 3 ) up the river one - half mile from M cFaddens Ford ; (4) on Bradleys Creek at Las Th m cassas . e foss ils most com only seen and most characteristic are the following " Salterella billings i ; LaphO Spi ra perangulata ; Li ospira abru a Helico oma tenesseens is H i i t t n . d ecl v s Le erditia abulites p ; ; ; p f .

S oil — . The soil derived from the Murfreesboro limestone i s a red

- of S f dish brown clay varying hades , requently containing blue or white

i chert . It var es in depth from zero along cliffs and glady places

S ix or f to eight feet , but probably averages less than four eet in depth .

Pi erce limes t one

Nam nd e ni i n — ff e a d t o . s fi Sa ord ays , This group has been so ’ ” named on account of its fine exposure in the section at Pierce s Mill e 1 . 869 . . is (G ol Tenn , , p This mill a half mile south of Walter

Hill . The Pierce formation includes the platy, fossiliferous beds and 36 GEOLOGY OF RU T HERFORD CO U NTY

w e e the massive coarse , granular limestone , bet e n the dense , massiv limestones o f the Ridley and Murfreesboro formations .

i e - 23 Th ckn ss . The Pierce formation varies in thickness from to

28 e b ut 25 27 . f et , is ordinaril y to feet thick — A real dis tr ib ution The Pierce formation outcrops in irregular rings about the little domes where the Murfreesboro limestone is found .

It occupies a total area of about fifteen square miles . good many where the whole thickness is prese nted for study . The formati

s o thin , the outcrops are narrow , averaging less than a quarter

two mile wide . The largest areas are at Florence , and two miles o f Walter Hill .

h rac er — C a t . , The Pierce formation consists of several member

or of them being limestone . The lower middle part generally

of sists massive beds Of coarsely crystalline , gray m containing frag ents of fossils , mainly ramose Bryozoa . The upper

of of of or half the formation is made up platy layers dense, blue

one - gray limestone half to two inches thick , intercalated with coarsel y

f o crystalline layers covered with fossils . The dense layers are not s

ilif r f s e ous . The platy beds are separated from each other by films o calcareous shale . The shale weathers rapidly, leaving the thin slabs scattered about .

’ S ection at the t e localit orm erl Pi erc e s M ill at W alt er Hi ll yp y, f y , Ridley

6 M ass e ense lue - ra oss erous l mes one . iv , d , b g y, f ilif i t Pi erce

- 5 . Th n e s of ense lue ra non oss erous m es one n erm e i b d d , b g y, f ilif li t , i t ix d

w h h n e s of ra c oarse ranu ar er oss erous m e it t i b d g y, ly g l , v y f ilif li s one s e ara e s a ar n s a rac on of an nch h ck t , p t d by h ly p ti g f ti i t i

M ass e u - ra en fin - n m 4. e se e ra e es one no oss s e ce a iv , bl g y, d , g i d li t ; f il x pt f ew b rachiop ods ; v ery little ch ert ; similar t o lVIurf reesb oro limes tone 4

Th n- e e en r - 3 . se a ue l mes one un oss erous 2 i b dd d , d , g y bl i t , f ilif

2 M ass . e ra un oss erous m es one s h c er 3 iv , d b , f ilif li t , lig tly h ty

Total Pi erce Murfreesb oro

1 Mass ark rab ense mes one con a ns some u sh - b ack ch er . e iv , d , d , d li t , t i bl i l t

at to no oss s p , f il Since the Pierce formation varies considerably in character from

s w n place to place, several ections ill be given to Show the variatio and the general characters as well . STRATIGRAPHY AND AREAL DISTRIBUTION

S ection two miles northwes t of M urfrees boro on Stones River

n e u - ra mass e l mes one orm n la es and con a n n 5 . e s e D , bl g y, iv i t f i g g d , t i i g

tro toc er um tho eras onioceras Ra nes uina and Cam S ma i , O r c , G , fi q

erella

4 L ue ense h n-b e ed l m es one some la ers oss erous . ight bl , d , t i dd i t , y f ilif , s ep arat e d by films of

L and ark lue ense and ranu ar n e s of os s erous 3 . ight d b , d g l , thi b d f ilif limes tone

2 ra -b ue rr e u ar e e chunk non oss erous m es one . G y l , i g l ly b dd d , y, f ilif li t , much like th e M urfreesb oro

Total Pi erce

1 ra m ass e non oss erous O t o 20 . D b , iv , f ilif

S ec tio lon L tle reek n M ur rees boro back o the ail n a g y C i f , f j

dley

5 ra en e m a l mes one . s ss e D b , d , iv i t Pi erce 4 T n b e s of ra sh a kno l me s one dark dense slab s and blue . hi d g y, ly, tty i t , , , ,

ranu ar s a s u of B r o oa all r e and r l g l l b f ll y z , ippl il

L h u m as e n m one h a a n ea ers 3 . e s a e l es s r s w ig t bl , iv , b d d i t , ly p ti g , th

s a rac o o s a un an o her oss s rare l bby ; b hi p d b d t , t f il

' 2 M ass oars ranu a u m n ra m n f b rach o o s . e c e r b e es o e e s o iv , , g l , l li t , f g t i p d ab undant

1 T n- e e o e - co or me n h sh a e ar n s lo er ar . e l s o e w w hi b dd d , d v l d i t it l y p ti g , p t

er oss erous B r o oa m os v y f ilif , y z tly

Total Pi erc e Mur rees oro b ed of c reek f b ,

S ecti on one and one -hal mil e north o Florence ormerl ' f s f , f y W ards M i ll Ridley

3 . ense mass e drab l m es one er oss erous at to D , iv , i t , v y f ilif p Pi erce

- 2. a ense l h ue un os s erous l mes one Pl ty, d , ig t bl , f ilif i t

- l . rre ular coarse ranu ar cros s b e e a ers som e of em u of I g , , g l , dd d l y , th f ll

ramos e B r o oa and h n a o e - co ore a ers som e of em y z , t i , pl ty, d v l d l y , th

co ere w h flat B r o oa and len cu ar masses 2 or 3 eet h ck v d it y z , ti l f t i ,

ma e u of o u ar B r o oa D i lotr a s een es un er the d p gl b l y z ( p yp ) , b t d , m ll ase of erce e ow wa er in r er i , b Pi b l t iv

Total Pi erce 38 GEOLOGY OF RU T H E RFORD COUNTY

ection at D avi M ill one mile eas t o e er o S s , f J fi s n Ridley 4 M as s e ra m es one wea her n ra s a ar n Coniocer . s as iv , d b li t t i g g y, h ly p ti g , and other fossils Uncon orm wa e marke f ity, v d Pi erce

3 B ue coarse cr s a ne mass e cross - e e ub li i mes on . s oo t c e l , , y t lli , iv , b dd d , li t , wea er n b rown f ew oss s th i g , f il n m n 2. M as s e ue coars e cr s a e es o e a r n r we e own. . iv , bl , , y t lli li t , th i g b

1 a ue ense un oss erous e s and a coarse ran . Pl ty, light bl , d , f ilif b d , pl ty, , g

u ar os s erous e s of l mes one a f ew nc es h ck r -marke l , f ilif b d i t i h t i , ill d ; e os ure ar es in ckness u and own s ream b ase not xp v i thi p d t ,

S ection one and one - o rth mile n rth O R k r at ar l no f u s o f uc e , M shal K bs Ridley

4 Mass ra dens l mes on con a n n ch r la rs f oss s . e e e e e ew iv , g y, i t , t i i g ty y , f il Pi erce 3 ra coarse cr s a ne l mes one ramose Br o oa and . G y, , y t lli i t , y z

2 Sla ense o e - co ore and ranu ar ra e s of m es one . bby, d , d v l d , g l , g y b d li t

s e ara e h n e s of ue S a e oss erous p t d by t i b d bl h l , f ilif

Total P i erce M urfreesb oro M 1 . ass e ra dense l mes one iv , d b , i t

i

ect n nd three- o rth orth o R ucker on road eas t o River S ion o e a f u s miles n f , f Ridley

M ass e o e - olore mes one no 7 . c iv , d v d li t , Pi erce 6 la dense do e l mes one w h ra ranu ar a es u l of B r o oa . P ty, , v i t , it g y, g l pl t f l y z

5 M ass e ranu ar cr s a ne ra mes one con a n n ramos e B r . iv , g l , y t lli , g y li t , t i i g y ozoa

4 B u s Sh a e and s ab s of mes one . l i h l l li t

Mas s e ranu ar cr s a n m es one con a n n ramos e B r o oa 3 . e iv , g l , y t lli li t , t i i g y z ( Ni cholsonella)

2 Y e o sh ra and ue a mes one f ew oss s . w ll i , g y bl , pl ty li t , f il

T otal Pi erce

Murf reesb oro

1 M ass e ra ens e mes one s ome ack c er . iv , d b , d li t , bl h t

AS shown by these sections the Pierce formation consists of pl

one or o f shaly beds with more beds massive , granular limestone , erall or t o o f or y in the middle at the p the formation , all more f w fossiliferous . It is sometimes very dificult to tell hether an out

o r f o r is Pierce Lebanon , they

40 GEOLOGY OF RUTHERFORD COUNTY

of practically every square mile the central plain , but these outcrop w expose only a few feet of the hole thickness of the formation .

Thickness — f . Although there are hundreds o exposures of the

c ley formation in the county, there is no complete se tion exposing the bottom and the top in such a position that its thickness coul accurately measured . The complete sections occupy horizontal

o r s tances of a half mile more, and the dip change so often proper correction for dip to be made to the vertical distance top and bottom is very uncertain .

f - Sa ford determined the thickness to be ninety five feet .

“ ' m of tion was easured at Las Casas , in the northeastern part ford , not far from the Wilson County line . It was taken on id B ” o f a rocky ridge . The entire R ley ed is presented in it .

. 1 86 f 0 . o e Tenn , , p The exact location his s ction canno m ter ined . to from his description At any rate , he failed take

the 20 count dip , which is north about feet to the

. was w ity His section at least half a mile long , hich would

1 0 e f fe t to the thickness . At most o the places where the Ri could be measured in its entirety the thickness was about 1 00 or f one eet . It gets somewhat thicker as goes toward the southern of of 1 20 the county, and reaches a maximum about feet at Bar and Marshall Knobs .

ha rac er — m wh o" C t . The Ridley formation is compo sed al ost

- massive , dense , drab colored limestone , with ordinarily very

- or . chert , but sometimes blue black white chert is abundant The varies from dove to light brown , and is frequently streaked r " lighter colored granular fucoidal markings . The color is la ge w to bituminous matter , hich can be smelled when the r broken , and the color disappears upon heating , leaving quicklime . The rock weathers into a light gray and fi appearance , but the weathering is very superficial , not more

n two o ut i ch or in depth , except where the fucoids dissolve , h the chunk rock at the surface full o f holes . T ere are locally

or bedded platy layers closely resembling the Pierce , as at Sul ff of . Springs , north Je erson The lithologic similarity between the Murfreesboro and the ley formations amounts almost to identity . They are alike

of 0 hardness , brittleness , presence chert , bituminous matter , STRATIGRAPHY AND AREAL DISTRIBUTION

l layers , the color and form upon weathering, and their inf uence ff topography and soil . The only discernible di erence is in the

ff . n s , which are widely di erent for the two formations Whe

s are absent , as is frequently the case , the identification is doubt ow or the Lebanon frequently fluted upon weather 5 and fantastic shapes are sometime s

e blocks .

’ The following section s Sh ow th e general ch ai acters and variations the Ridley formation "

t o ank o tone River one mile t o S ec i n on b f S s , wes f Jeflers on

Top eroded away ra somewh a ranular mass e l mest one w h h n rr e ular sh al G y, t g , iv i it t i , i g , y ar n s s ome roun e m asses of ch er S tromatoceri um Anolo p ti g ; d d t ; ,

ti chia R a ne uina , fi s q t

Two mass e e es of en se ra mes one er res s an t o weath iv l dg d , d b li t , v y i t t

' er n l e ch er and no oss s i g , ittl t f il

T n- b ed e ense b r le rab l m es one in eds 1 t o 2 nch es h ck hi d d , d , itt , d i t b i t i , n ul n n mm with u d ati g shaly p arti gs ; Camerella co on .

M ass e ra ens e l mes one no oss s iv , d b , d i t , f il

M as s e ra ranu ar l mes one w h two- nch ar n s of rown iv , g y, g l i t , it i p ti g b

i sh s ub - oo c l mes one at b ed of r er b as e not e os e , liti i t , iv , xp d

Total Ridley exp osed

S ection down the eas t s id e of M ars hall Kno b

M ass e dra en s e l mes one wea er n ra and ranular some iv , b , d i t , th i g g y g ,

ch er os s ls enera rare some la ers con a n R a nes uina Her t f i g lly , y t i fi q , b ert ell e l r 80 a l a u o a t ra o sm h n a r s . b s O s c ds a l Ce a o od a d s o od . g , , p p s G p y l l t

Th n- b e e o e - co ore mes one w h s al ar n s 1 0 i dd d , d v l d li t , it h y p ti g ra l m es one l k 4 e No. 20 D b i t , i

Total Ridley

1 M . ass e and a oss erous l mes one iv pl ty, f ilif i t

Strati ra hic r e latio — g p ns . The Ridley apparently lies conformable

th ff o f the e Pierce excepting at Je erson , where the lowest beds

upon an undulating surface . Elsewhere the beds below and

contact are parallel , but there is a marked change in the

the . two formations , due probably to changed environment 42 GEOLOGY OF RU T H E RFORD COUNTY

The unconformity in any event could not be great , since the

i s so h w formation thin but very constant in t ickness , and no here

of any evidence an erosional interval , except the very slight D avis Mill . — Fo ss ils The Ridley contains much fewer foss ils than the Pie h and more t an the Murfreesboro , but they are not generally a c

f of Spicuous feature o the rock . In the northern half the

Stromatocerium is generally present and sometimes abundant, the southern half of the county it is absent . The best collecting ’ ties f or Ridley fossils are " 1 ) In front of Vaughn s store at v 2 in of two ille ; ( ) front the Silver Spring School , miles no F 3 lorence ; ( ) at Stones River on the Franklin pike . The following are the most common and characteristic and the presence of any three o f them will ide

" S tro mat ocer ium r u osum Camarella Ridley g , be llaro osa Goni ceras ance s O r bi n ella s ublamellosa Lios ira co g , p , g y , P vexa Ra nes ui minne e i r o rh r na na sot ns s P to ncha id le a . , fi q , and — y y S oil The soil derived from the Ridley formation is clay of

- reddish brown color , the shade Of brown varying somewhat , d ing upon conditions after the soil was formed . The subsoil is

- of brick brown , and the surface soil is generally a darker color count of the organic matter present . In wet places the soil is “ ” c rawfi sh yellow called soil , and where the iron and manganese present these compounds

o f concretions , the size buckshot , and soil “ ” these pellets is called buckshot soil . In gentle sways the soil

o f of -b mixture hill wash and residual clay, and is a yellowish color . The soil covering the Ridley limestone varie s in depth

5 o r 6 s 3 zero on the glades to feet, but average less than

t o f It is generally without cher , but sometimes chert a blue , white, m red color is abundant , as in the vicinity of Black an .

L eb anon f ormati on — Name and d efinition The Lebanon formation was originally “ ” 1 b e 86 . . 9 named Glade limestone by Safford ( Geol . Tenn , , p “ " ’ cause it is pre - eminently the bed of the great Cedar Glad es of the ” ff e Central Basin . Sa ord and Killebrew chang d the name to Lebanon

1 1 0 . . 9 limestone (Elem . Geol . Tenn , , p evidently from the

o f Lebanon in Wilson County, which is located upon STRATIGRAPHY AND ' AREAL DISTRIBUTION

had previously been used by Safford for the entire Stone s

b ut one th e d Carters , it is now restricted to formation of

iver group . Safford does not s ay exactly where the type section of the Lebanon and the only section he gives in his original description is “near ll ad vi e . . 1 869 y . ( Geol Tenn , , p . This would probably stand the type section; and is as follows "

’ — ( 5 ) Cart er s Creek lim est one The rocks of thi s b ed form th e t op of the

are h ck e e and ha e a ckness of 50 ee hill , t i b dd d , v thi f t . — 4 Glade lim es t one Th n ed ed a mes one res en n the usual ( ) i b d , fl ggy li t , p ti g

ea ures of th e rou con a ns a hea b e e a er a ou ree ee f t g p ; t i vy dd d l y , b t th f t

h ck near th m e nd ano e nea h En r h kne e a r r t e as e . e c ss t i , iddl , th b ti t i , 1 1 8 ee f t . — 3 Ridle lim es tone Th s cons u es the b ase of th e sec on and orms ( ) y i tit t ti , f

h f th a r h as an e osure o f a bluff running down t o t e level o e w te . It xp ” 35 feet . — Areal distr ibution The Lebanon formation is the surface rock of

- one or 1 60 . r fourth the area of the county, about square miles

land outcrops extend nearly around the county, bordering the flat

the central plain . The outcrops are from two to five miles wide the eastern Side of the county and from one -half to two miles W i de

westein e - the Side . It generally. is the low st rock in the hills bor

in out gthe county , and the lower part frequently extends over the

e in country in a thin ven er , as it does to a marked extent the

out southeastern and the southwestern corners of the country . The

of o f crop the lower part the formation is generally flat or rolling , but the upper part is usually steep , especially where it is still covered with the massive Carters . limestone . The whole formation tends to

S O o c produce flat areas because it weathers rapidly, and the reason it cupies the hilly districts is on account of the protection from weather

rded by the resistant Carters limestone above.

kness — . 80 1 20 The Lebanon varies from to feet in thickness ,

v a erage thickness in the county o f more than 1 00 feet . It is tern Side o f the county and of the maxi

c Side . The thinnest se tion noted was at

o f miles east Murfreesboro on the Halls Hill pike . thickness is probably due to the variation in amount in ll a . w y deposited It is possible , ho ever , that there Lebanon se diments were laid down 44 GE OLOGY O F RUTHERFORD COUNTY

and that some o f the rock was removed . The evidence favoring unconformity between the Lebanon and Carters is discusse d under latter heading .

r e — Cha act r . The Lebanon formation is made up very largely

la ers s or - thin y of den e , drab dove colored , fossiliferous separated by layers a fraction o f an inch thick of blue or yellow

o f shale . In the lower half the formation there is frequently a ma

of bed drab , dense , unfossiliferous limestone , very similar to the 2 1 1 ley , varying in thickness from to feet . The platy layers

1 6 2 o r 3 i from to inches in thickness , averaging nches ,

o f of a great variety limestone Of a gray, dove or

layers are dense and unfossiliferous , others crystalline ; some are made up almost wholly

Pianod ema of fl of Le e , ramose Bryozoa , of abellate Bryozoa , p o r of b e a com ination of fossils ; some beds are sandy , som lami

e - and some mottled . Rippl , rill and wave marks are common . The Lebanon and Pierce formations are very similar in lithol w f characters , and hen a thin , isolated outcrop o platy limestone found it is often very difficult to tell whether it is Lebanon o r Pier

e In such cas s the only safe guide is fossils .

' Outcrops exposing the whole of the formation may be seen

any . c places in the county The following se tion , taken at

of h is representative the formation anywhere in the county, alt o

other sections will differ in details .

S ec tion one -hal mi le s outh o Kittrell rom Cri le Creek to t o o h l f f , f pp p f il Hermitage

1 0. B ue am na e calcareous s an s tone wea er n e ow l , l i t d , d , th i g y ll Cart ers

9 . M ass e ra or o e mes one Tetradium c ellulos um a un an iv , g y d v li t , b d t Leb anon

8 . ranu ar ra and ense o e un oss erous b eds 1 to 3 nch es G l , g y d , d v , f ilif , i

h ck s e ara e h n lms of t i , p t d by t i fi

7 . ra com ac lam na e d un oss erous m es one i n e s 6 nc es G y, p t , i t , f ilif li t b d i h

ra ne ranu ar mass e mes one con a n n enses u t o 4 G y, fi ly g l , iv li t , t i i g l p inches thick of ramos e B ryozoa

ranu ar ra and com ac ue un oss erous l m es one in e s G l , g y, p t , bl , f ilif i t b d

1 t o 6 inch es thi ck .

Kno ra mes one i n e s one - a nc ck s e ara e n tty, d b li t b d h lf i h thi , p t d by thi a ers of S a e some l y h l ,

ra ranu ar s a s of mes one and sha e a era n 2 nc es h ck G y, g l l b li t l , v gi g i h t i , f ew fossils STRATIGRAPHY AND AREAL DISTRIBUTION

e u ar b e e ra coarse l mes one and sha e r and r le 2. rr I g l ly dd d , g y, i t l , ill ipp

marks and wa e - marks 4 ee on and 6 nc es ee f ew oss s , v f t l g i h d p , f il

Total Leb anon

1 M ass e b e s 4 ee h ck of com ac ra l mes one wea h er n mot . iv d f t t i p t , d b i t t i g tled and full of h oles ( fucoids ) 1 2 — S tratigraphic relations The Lebanon lies conformably on the

dle o f y, but it is not improbable that parts the country were out of t the beginning o f the Lebanon sedimentary epoch o r during

i s f ch . There a considerable change in the auna between the t o and Lebanon formations , but the change is probably due er water conditions of the Lebanon sea and not to an unre

r f f t Lebanon is more o less ossili erous throughou ,

r s f ar more abundant in some localities than in othe , re barren and others are made up entirely of shells of one

i ds a foot or two thick composed entirely o f a species of

tes s are sometimes een , as along the railroad two miles

of f or south Murfreesboro . The best collecting localities Lebanon ’ fossil s are " ( 1 ) back of Robinson s store at Big Springs ; ( 2) one ’ half miles south of Miles Ford ; ( 3 ) one - fourth mil e north of Watson s store on the Shelbyville pike . The most abundant and characteristic fossils o f the Lebanon are

enidium anthonens e Batostom libana E s charo s . S c a p , , ,

Le erditia abulites O rthis tricena ria Ph ra molites p f , , g

d ema s ubae uata Pach dict c lia a P r m a . o t te o c q , y y f f , yg

Rh nchotrema -minnes otens is Chasma tO o ra s ublaxa y , p ,

ra i i c m Z i r r . a s t u S a sa o di f p , n p fl . l — . The soil derived from the Lebanon formation i s a reddish

o f f clay various Shades , depending upon the amount o organic

of o f a present and the state oxidation the iron in the cl y . is generally absent or if present so Shallow that it can seldom be

led . What little soil there is present is in the cracks o f the

or o f ff ck mixed up with slabs rock , but it is su icient to produce

good crop Of cedars . Nearly all o f the surface area occupied by

. o r e mation is glady Sometimes the soil is four five fe t deep ,

" s se places will raise good crop during wet seasons , but during

on o f acted drought the crop dries up and dies , account the h old water . 46 GE OLOGY OF RUTHERFORD COUNTY

B LACK RIVE R GROUP This group includes in Rutherford County the Carters limestone f w e o Lo ville age , imm diately above the Lebanon , and possibly an unnamed formation occurring as a lense above the Carters in the f D o . southeastern corner the county, of ecorah age

Gart ers limest one — Name and d efinition The Carters limestone was originally named ’ ff 1 869 a . . . C rter s Creek limestone by Sa ord ( Geol Tenn , , p ’ f 1 0 from Carter s Creek in Maury County . Sa ford and Killebrew ( 90 )

e shortened the nam to Carter limestone, and Hayes and Ulrich (U . 1 9 3 . . 95 0 . S G . S Folio , ) changed the name to Carters limestone It

50 1 00 e was defined to include the massive , dove limestone , to fe t t hick , above the Lebanon limestone and below the sandy limestone “ ” f r o the Orthis Bed o Hermitage . — A real distr ibution The Carters limestone forms the tops of sev

s on eral hill bordering the central plain , but it forms the middle part

f f i rre u o most o the hills bordering the county . The outcrops form g lar s m one - of bands about the hill , fro fourth a mile to a mile wide,

v o er an area of about 50 square miles of the county . Good outcrops

b e s a i s f o r m akes may een lmost anywhere, where it the surface rock , it

Th e w steep slopes which are generally devoid of soil . to n of Eagle d of e D onnels . an ville and the villages Milton , Hoover, Short Cre k , , V ersailles are built upon the Carters limestone . A good outcrop may be seen at Bowling Hill , miles northeast of Murfreesboro .

Thickness —I to . n Rutherford County the Carters varies from 55 80 65 . feet in thickness , but it is generally about feet thick The

t one - o f greates thickness noted was half mile south Kittrell , and the

- thinnest One half mile east of the county line on the Franklin road . 40 60 In the type area , Maury county, it varies from to feet, and in Wilson county the maximum thicknes s measured by Safford was 95 t. S . o ut . . . fee As pointed by Hayes and Ulrich ( U S G , Folio this variation in thickness was not entirely due to variation in amount originally deposited , but was for the most part due to erosion before the was un deposition of the succeeding formation . The thickness 80 1 00 doubtedly much more uniform , possibly to feet , at the end o f the Carters deposition stage .

Characte r — f one . The Carters limestone consists o massive beds

e . to four f et thick Of very dense , dove , light blue or gray limestone

48 GEOLOGY OF RU T HERFORD COUNTY

The typical Lowville and the Carters are identical in lith olo i s eters , as noted above , and have a like th ckness . The guid

e r dium ce llulos um Colum na ria halli T t a and , are abundant in the L ville and characteristic of that formation wherever found .

' Fo s i s —Co lum na ria ha lli d s l . is abun ant in the Carters and

2 to 8 e ee nearly spherical heads , inch s in diameter, may be s n ili fi nearly all outcrops of the formation . The fossil is S ci ed as limestone weathers . This species is not confined to the Carters occurs rarely in the Pierce and Ridley and in other regions it

Tetradium ce llulos um in the Trenton . is very abundant in the part of the Carters and is found in no other formation b

V Tet radium ille . Other species occasionally met with are

olum na ri r i i tre telasma C a ca t erens s C . hall S ( Similar to ) , p

D s tactO S on ia m inor e o f y p g , and various sp cies brachiopods ffi and cephalopods recognizable with di culty . — S oil The Carters for the most part occurs on steep Slopes

e very littl soil can accumulate , but the upper part is sometime

l lim est y level , where the less resistant Hermitage

. w back The Soil is bright , bro nish red clay

from the Carters , but most of the soil overly mixture o f residual clay and b ill wash from and of a yellowish brown color . It is shall a or four feet deep , and cont ins some chert ,

Of limestone . The soil is very productive where deep enough

f o r water the crop throughout the summer . Probably less square miles of the area of the county occupied by Carters

is tilled . The Carters glades grow both cedars and hardwood

TRE NTON GROUP The Trenton group in Rutherford County consists of at least

formations , the Hermitage at the bottom , Bigby and Cannon .

H ermit age f ormati on — Nam e and d efiniti o n The Hermitage formation was named “ " ’ S a Hayes and Ulrich , who y, The name Hermitage is derived fr

o f old the station that name , Situated near the home

o n Jackson , the Tennessee Central Railroad , where a f S . was secured ( U . S . G . , Folio Sa ford first u formation as a group of blue , silicio s , and sandy lim layers of which are literally made STRATIGRA PHY AN D AREAL DISTRIBUTION 49

dinaria e . . Iu , and he therefore call d the formation Orthis bed ( Geol

Tenn . , p . — Ar eal dis tribution In Rutherford County the Hermitage occupies a position at or near the tops of many o f the hills in the north and

o f one - east Sides the county, and outcrops in a strip about eighth of a mile wide from 3 00 to 400 feet below the tops of the high hills and ridges along the county line from Milton , south and west to Fos , terville . Along the western side of the county the outcrops are much

- l wider , from one half to a mile wide , but it occurs only in the hil y

i s of 25 districts . The Hermitage the surface rock some square miles of the county . This formation is a conspicuous one in the hills surrounding the

Central Basin , and rocks of the same age have been recognized along the Tennessee River in Hardin and Wayne counties , and in the valley f o East Tennessee . — i ar . 40 70 Th ckness . The Hermitage v ies in thickness from to feet D in Maury , Williamson and avidson counties , and in Rutherford it

50 0 e varies from to as much as 9 fe t . This latter thickness probably includes the Bigby formation , which is generally absent in Ruther

r ford County o indistinguishable from the Hermitage . The average thickness of the Hermitage is 70 to 75 feet . ' — Chara t r - c e . The Hermitage is in general a thin bedded , blue , sili l c ous limestone , the beds separated by thin layers of blue Shale . Along

w o f the estern side the county the formation is largely sandstone , calcareous sandstone , and sandy shale , containing laminated phos phatic layers . The formation weathers rapidly into a yellowish or w light brown sandy soil , generally containing brown slabs which , hen broken , Show a blue center . In the counties along the western border of the Central Basin the Hermitage contains great numbers o f D almane lla fe r tilis Bassler

O rthi s testudinaria O f f d a l Sa for ) , but this shell is r re y seen in

u t the Hermitage o f R therford County . In this county his formation is not generally fossiliferous , although in some localities fossils occur in considerable numbers . This formation is of great interest on account O f three things ( I ) it weathers rapidly into a fertile , sandy soil , and makes a bench around the hills which is generally farmed ; ( 2 ) it is th e only forma

ro " tion in the county which contains lime, sand , and clay in proper p portions to permit of its use as a source o f hydraulic cement ; ( 3 ) 50 GEOLOGY OF RU T H E RFORD COUNTY

it contains , along the western edge of the county, considerable rock

o f u phosphate which will sometime be commercial val e . The following sections will illustrate the vari ation in character of the sediments of the Hermitage formation

S ecti on one mile north eas t of Hoover

Cannon

M ass e ra or ra com ac l mes one s ome oss s 5 . iv , d b g y, p t i t , f il Hermitage 4 rre u ar b e e ar ac eous mes one wea her n e ow Tet ra . I g l ly dd d , gill li t t i g y ll ; dium minus Rh nch ot rema s ub tri onale and Hallo ori na arva , y g , p p

h r r n 3 . W e anu ar or c s a e mas s e mes one con a n n s reaks it , g l , y t lli , iv li t t i i g t and spots of yellow c al cit e ; fragments of D almanella fert ilis and oth er fossils ab undant

m e n m n 2 . Th n e s of ue s c ous s o e a a e san s one and f os i b d bl , ili i li t , l i t d d t ,

silif erous mes one s e ara e h n e s of r een s - rab cal li t , p t d by t i b d g i h d ,

careous S a e oss s a un an es ec a Z os ira rec urviros t ris h l ; f il b d t , p i lly yg p ,

Pach diCt a c oliata and ar ous os raco s y y f . f v i t d

Total Hermitag e Cart ers

1 M ass e o e and ra mes one . iv , d v g y li t

S ection one- hal mile eas t o B eulah Ch ur ch near W illiams on Count line f f , y

Cannon

6 M ass e ra m n - n h a a e . es o e h n e e a d s a t s iv , g y li t , t i b dd d ly b Hermitage

5 . Y e ow s an c a sh a e ll , dy, l y l

4 ra fi - m na an one . ne ra ne so la e s s G y, g i d , ft , i t d d t

F ss e n n n r h 3 . sa s a e ro a s a s one wh e es i il , dy h l , p b bly d t f

2 B r n m m n . ow a na e os a c es o e , l i t d , ph ph ti li t

Total Hermitage Cart ers 1 M m . ass e w e es one iv , hit li t

Strati ra i r i n — a s g ph c e lat o s . The Hermit ge lie unconformably upon

o f two . the Carters , but the strata the formations are nearly parallel The two formations differ g reatl y in lithologic character and fossil d content . The Carters varies from 55 to 80 feet thick in Rutherfor u 40 95 Co nty, and from to feet in other localities , the variation being

uncon partly due to Paleozoic erosion . In some places the erosional

o f formity can be demonstrated . In this region all the Black River STRATIGRAPHY AND AREAL DISTRIBUTION

as w s n except the Carters is missing, well as the lo e t Trento

Sville ) . — Fossils cannot be relied upon for the identification of

on of t tage in Rutherford County account their scarci y, the sandy character of the rock being more reliable . Fossils are abun dant o ne mile northeast o f Hoover and a species o f M onticulip ora

Pras o ora atera ast of Milton . p p is common in Maury not a single specimen has been discovered in Ruther

D a lmane lla e rtilis O rthis testud ina ria f f rd County . Even f ( o Sa ford ) i s rarely seen in this county .

S o il —T . he rocks o f the Hermitage weather down rapidly and make

. o f a sandy, fertile soil Along the eastern side the county the soil

e o f b ut contains some clay and und composed plates limestone , it is very fertile and easily tilled , although the slopes are fairly steep ff f and di icult to approach over the Carters cli f . Along the western side of the county the soil derived from the Hermitage formation i s a

on yellowish sand containing much phosphate . It occurs a fairly nk level bench near the top or middle of the hills , is free from chu s of rock except those that have rolled down the hill , is easily tilled and

on l raises good wheat . Corn does not stand wet weather well this soi ,

n f . probably o _account of the over supply o phosphorus

B igby f ormati on — Nam e and d efini ti on The Bigby limestone was named by Hayes 3 . 95 1 90 . . S . and Ulrich (U S G , Folio , ) from Big Bigby creek in n i s . . w s e Maury County, Ten , along hich it well xpo ed They defined

of s -c o r it as a nearly uniform series emi olitic granular , crystalline;

or 30 laminated , phosphatic limestone, gray bluish in color , and to ”

1- 00 D feet in thickness . The Bigby includes the Capitol , ove , and Ward limestones o f Safford .

A real dis tributi o n —In f al . Ruther ord County the Bigby is nearly

or i t ways missing, if present is indistinguishable , from the Herm age ,

th e c t except in a few localities . It is mapped with Hermitage, ex ep y in a few places along the northwestern line o f the county where the two formations could be distinguished on lithologic or faunal grounds . " sa t the It is safe to y tha Bigby is usuallymissing in this county , hav

e ing never be n deposited . The only places the Bigby was recognized

two o f i e with certainty were miles west Almav lle , and n ar the corner o f D C n u f " Williamson , avidson , and Rutherford ou ties . It was do bt ully 5 2 GEOLOGY OF RUTHERFORD COUNTY

o f identified miles northeast of Hoover , and miles east Mil w ton . The surface area Occupied by Bigby outcrops is bet een one and two square miles in this county .

i e s —I 3 Th ckn s . n s 0 thickness the Bigby varie from zero to feet . 3 0 1 00 In Maury County it varies from to feet .

hara er — C ct . The Bigby varies considerably in character , even f among the limited outcrops o this county . West of Almaville it is a gray , massive , granular , laminated limestone , some beds being sandy 2 and 0 . others shaly and very fossiliferous , and about feet thick The fossils occurring ab undantly at this locality are He bert ella frankfo rt

i Rh nch otr ema incre b es ce ns Hallo o ra m ultitabulata ar Plat ens s v . , y , p , y stro hia c o lbi ens is Tet rad ium minus s e p , , and other undetermined p

. o r cies Farther north the formation is a granular , gray brown , lam

n te - o f f o s i a d and cross bedded limestone without fossils . Most the

m Co sils co mon in the Bigby of Maury County, especially are not present in Rutherford .

tr i r h e i — S at g ap ic r lat ons . The Bigby lies unconformably upon f u d . o Hermitage , altho gh the be s are parallel The proof a break

m o f sedi entation is the absence of the Bigby in most the county ,

h t o o f t ough this may be due erosion , and the presence a formati w the Wilmore limestone , in Kentucky bet een the Hermitage and Bi The Bigby " is an overlapping formation and probably did not cover th e whole o f the Nashville dome .

Cannon limes t one — Nam e and d efinition The name Cannon as a formational name 2 9 1 1 Am l 2 1 . . vo . was introduced by Ulrich ( Bull . Geol . Soc . , , , p 41 7 ) from Cannon County, Tenn . , where the formation is well de velo ed o f Tr en p and well exposed . It includes all of the limestones l ton age above the Hermitage and below the Chattanooga in 3 00 . Shale, and is Cannon County fully feet thick — Areal dis tribution The Cannon formation occurs on the steep slopes near the tops of the highest hills and ridges near the county

on o f u . o line the east , south and west sides the co nty Its occupy a surface area o f about 1 6 square miles in Rutherford

of 800 1 The bottom the formation occurs at elevations of to , d epending upon the locality .

Thickness —In . thickness the Cannon formation varies b and 3 00 feet . It is thinnest on the west side of the county STRATIGRAPHY AN D AREAL DISTRIBUTION 53

the o f Milton . Most of outcrops in the county have a thick 2 about 40 feet . — The Cannon formation consists largely of massive , f . o es , with occasional thin , shaly streaks Some the beds

some knotty and earthy, and many of them very fos

f The Cannon formation includes undi ferentiated Bigby , Flanagan , l r vil e n . y , Catheys , and Cy thiana These formations will no doubt

th e eventually recognized in central Tennessee, but until faunas the diff erent beds of the Cannon are better known it is impracti l e to attempt to map the formations as recognized in Kentucky .

r S trati ra hi rel on g p c ati s . The Cannon lies unconform ably upon the W i lmore limestone is missing in this county, and the

n t o r not absent . It is o definitely known whether w a break bet een the Bigby and Cannon , but the absence or of the Bigby indic ates either a period of nondeposition or

erosion , hence an unconformity . — Fo ssils The most common and easily recognizable fossils in

Canrion " S tromato cerium us tulosum Colum na ria alveolata are p , ,

i i m r T era Te rad um o lu na e . A ct no c s s . t c p , ,

lo ma of Cyc ne . Undetermined species brach

are pelecypods , corals , bryozoa and other forms

w s the Cannon limestone al ays makes steep slope , the i s . w Shallow It is a yello ish , sandy clay and composed o f res idual

b ill o f and wash , always containing blocks chert , geodes , S ilici fossils and chunks o f limestone which have rolled down from the

rm ati ons The . soil is very fertile and is cultivated in corn erever possible . M AYS VILLE GROUP

L eip ers f ormati on — Nam e and d efinitio n The Leipers formation was named by Hayes

. . S . d Ulrich from Leipers Creek in Maury County (U S . G , Folio

e o f Th y define it , in the eastern half the Columbia quad “ t o gle , as a knotty, earthy limestone at the p , with similar but more l f . o y and highly fossiliferous beds below It is Maysville age ,

C a middle incinn tian . 54 GE O L O GY or R U T H E R F O R D C O U N T Y

re i tri i n — A al d s but o . The Leipers occurs in this county on the of w a five hills bet een Williamson and Rutherford counties , area of less than half a square mile . It never was deposited over o f the u N sea 1 county, since m ch of the ashville dome was above during that time .

haract r — f C e . o The Leipers consists knotty, earthy limestones

o f o r es eci beds calcareous shale , all more less fossiliferous , p at the top . The thickness could not be exactly determined on o f b ut the contact between it and the Cannon being covered , between 90 and 1 00 feet . The characteristic and abundant fossils

l s r a n i r a P at t o hia ond e r osa . R es u na alte nat He b e rt e lla s in y p p fi q ,

Stro homena lano convexa p p , and several species of bryozoa .

Strati ra hic relatio ns — e g p . The Leipers li s unconformably u

Cannon ( in Maury County upon the Catheys ) , which it much in lithologic characters . The Utica and Eden of cinnatian age are missing in this region but are present in

nnati region . On account of the contact being covered in this regi it could not be determined whether it was uneven or not .

U NCONFORM I TY B E TW E E N T H E CA N N ON A N D T H E CHATTANOOGA S H ALE

o f u The upper part the Ordovician system , the Richmond gro p

two w o f D and hole systems rocks , the Silurian and evonian ,

d o f s s sente elsewhere by several thousand feet lime tone , sand

and . shales , are entirely missing in Rutherford County The of the Nashville structural dome o r arch was an island slightly sea se a level during those periods , but the surrounded it durin

o f one o r eral epochs the Silurian period , and covered more of D the dome at several times in the evonian period , as the presence o f Sil urian strata on all sides of the Central

D th e . by evonian rocks on north , west , and south sides The s ero d trata did not rise far above sea level , for they are not they would have been had they been far above se a level .

' was w o ff Mississi , ho ever, planed by the beginning of the pp and its flanks covered by wedges of Silurian and Devonian

56 GE O L O GY OF R U T H E R F ORD C O U N T Y

- fi - haracter . ne C The Hardin member is a gray, grained sandstone , containing waterworn fragments Of Ordovician fossils . NO fossils were

e discovered which belonged t o the member its lf . “ ” of m The black shale consists throughout a dead black , la inated , carbonaceous and bituminous shale , containing numerous rounded “ ’ ” nodules Of iron pyrite o r fools gold . Conodonts and minute fish

- Lin ula teeth occur in abundance , and thin shelled brachiopods , g , “ ’ on occasionally seen . This member is frequently called slate , f of o . count the property splitting into thin plates It is , h solidified , carbonaceous mud . The “black” shale will give a blaze when thrown on a good The bituminous and carbonaceous matter is distilled Off as f the lammable gases , but the body Of shale will not burn an i s not enough Of carbonaceous matter present to support

s o e less other fuel is added . As has been often point d out , t

o f c O shale has no value as fuel , nor does it contain beds b een prospected in hundreds Of places for coal but none has ever

. O il been found Considerable can be distilled from the shale , possibly 1 0 as much as gallons to the ton , but it cannot be extracted profitably at the present time .

Strati ra hic re latio ns - o n g p . The Chattanooga lies unconformably

on on the Cannon the eastern side of the county, and the Leipers on l the western side . The strata at the contact are usually paralle , but in some places the eroded surfaces of the Cannon is irregular .

F t a ne orma on . P y f ti — Nam e and e ni n d . . d tio . was fi The Ft . Payne chert name by C W

. G Am . 1 890 . Hayes (Bull eol . Soc . , vol . II , , p and was later 2 4 6 8 . . . S . described by him (U S G , Folios , , , ) as a very silicious , wi limestone th heavy beds Of chert at the base , above the Chattanooga

e shal and below the Bangor limestone , and varying in thickness from 75 2 ff 0 . 0 e . to fe t The type locality is Ft . Payne , Alabama Sa ord “ called the formation the Protean member o f the Siliceous Group ( . . 1 869 ff w Geol Tenn , , p . Sa ord and Killebre renamed the formation Tullahoma , from Tullahoma , Tenn . , which is located upon 1 9 0 ' . 0 . the formation (Elem . Geol . Tenn , , p Since the terms

I" . t t Payne and Tullahoma refer o exactly the same formation , the former takes precedence on the ground Of priority . STRATIGRAP HY AND AREAL DISTRIBUTION — Areal d ist ribution The Ft . Payne formation occupies the sum ts Of the highest hills and ridges in the county . The largest area is the southeastern corner o f the County line between the Bradyville

two y hills in the western part Of the county, d Hill , are cappe with it . The Ft . Payne

Of about two square miles Of the county .

O le O f thickness the Ft . Payne is not shown The greatest thickness presented in j ust east

i s 1 1 7 feet thick . In Warren County the forma

thick (Hayes) . m h part consists Of la inated , sandy s ale with ellow chert from a f ew inches to four feet

5 . u o f u The pper part consists very silicio s , laminated lime l hin beds Of chert . The whole formation gives the appear

sh al s and ton w s e O f . y , ith beds chert , upon weathering The

e which is blue, coarse, sandy and very fossilif rous , is

chert results from the decay Of beds of limestone and the

tion Of the silica in these beds . Geodes , from the size Of a ’ to the size Of a person s head , are abundant throughout the

on . They result from the replacement Of the lime in fossils As the silica crystallizes it expands and makes cracks through I . a out More silic is deposited in the cracks , especially at the

ich in crystallizing expands and makes more cracks . In this

outside grows faster than the inside , which leaves the geodes Very soon after the formation O f the geode th e fossil is de

s o that it cannot be identifi ed . Under favorable conditions

et tw “ t to be o feet in diame er . Geodes are mainly a surface b ut being formed as the rock decays , sometimes they

s the body Of the rock , in which ca e they are almost

l ti n — i f w 0 re a o s . s The Ft . Payne uncon ormable ith the Al ut the beds Of the two formations are parallel . “ ” th e the t o of ough there is a break in record at p the black shale,

Kinderh ookian presented elsewhere by the Maury member , the entire

r e - f O sa ian ries and the lower half o thre fourths O the g series , there very little evidence of erosion in this county . At the north side 1 00 about feet thick , comes 5 8 GEOLOGY O F RUTHERFORD COUN TY

between the Chattanooga and Ft . Payne formations . Evidently top Of the Nashville dome was not far above sea level during last interval . i — S o l The soil derived from the Ft . Payne formation is sand

i s and full o f chert . It works well but rather poor and raises crops . It is deficient in lime, phosphorous and organic matter .

' e r i s suitable for fruit raising , esp cially peaches and apples . The p

h ri ci al . w t v p tree growing in the Ft Payne soil is the chestnut , hich

or r and reaches a large size , up to three fou feet in diameter . GEOLOGIC STRUCTURE

CHAPTE R V .

GE OLOG IC STRU CTU RE

i — D efinit o n . Ge ologic structure has reference to the position at the

e time Of the beds of rock consid red as extensive sheets or strata ,

or inclined in folds , and also fractures ( j oints ) n aced strata ( faults) . Structure has o reference to surface f to o . r topography , but the attitude the strata themselves

the rocks were deposited as sediment in the bodies O f water

vered Rutherford County time after time , they were nearly

1 At not . the present time they are horizontal , but tipped in Wh en the strata dip in every direction from a

ructur r e is called a dome o arch . When the rocks w up ard , the fold is called an anticline , and when the fold

a . rd like a trough , it is called syncline Small domes , anti

and synclines are the prevailing structures in Rutherford County .

NASHVILL E D OM E

o f e u The whole Middle Tennesse , from the C mberland Plateau

s of a n n the Tennes ee River , is in the form low dome, k ow to

i on or sts as the Nashv ll e dome . The center Of the dome is line between Rutherford and Bedford counties in the neigh

O f or Fosterville a few miles west Of that place , near Mid precise location O f the highest point on the dome cannot determined until a topOgr aphic map covering that region is com

ted . The top Of the black shale is taken as a reference surface to show “ ” m h as e re the size and for Of the dome . Where the black shale be n moved its former position c an be calculated by adding the thickness O f rock intervening at other places between the surface and the top

For the shale . instance, its former position above Murfreesboro ourt House square) i s ascertained to be feet above s ea level

” 590 e of adding f et , the thickness rock removed , to the surface ele 61 0 feet, thus 60 GEOLOGY OF RUTHERFORD COUNTY

Black shale Cannon lim estone Hermitag e lim estone Carters lim estone Leb anon lim es tone Ridley limes tone

Surface elevati on

T op O f Black Shale

In like manner the elevation of the black shale for other p of was the county determined , in addition to the places where i still preserved and its elevation shown upon the topographic map . The highest elevation occupied by the “black shale in Middle h o f essee is one mile south Fosterville , where it is about above sea level . The shale is still present at this place accurate leveling will revise this figure . From the vicinity O terville and Midland the strata dip away in all directions . At “ 40 ab O ville , miles south , the black shale has an elevation of

n of 1 5 ee . feet , givi g a southerly dip about f t to the mile The t 60 490 ion at Centerville , miles west , is feet , a dip Of

. 60 the mile At Ashland City, miles northwest , the shale is

400 i s 1 5 feet in elevation , and the dip in this direction feet to

. w 55 mile Bet een Gallatin and Fountain Head , miles north , the 600 1 5 vation Of the shale is about feet , a dip Of feet to the mile

McMinnville 700 200 e w , feet ( fe t belo the surface) , an easterly

O f 1 7 feet to the mile . The dome is elongated along an axis n 5 1 0 ortheast and southwest , and the dip is to feet to the mi th s e e directions . The axis passes through Fosterville and Lasc and is extended in a line passing through these two towns .

d b ut The Central Basin is develope in the top Of the dome , on its northwestern limb . The axis Of the dome runs through t dle Of the eastern half Of the Central Basin and

o r w middle lo est part of the Basin . The Basin ha or cut out b y the streams on account O f the slopi strata . The several rivers which drain the Basin

O f direction the greatest dip O f the strata . The cuts across the northern end of the dome , but GEOLOGIC STRUCTURE 61

bend northward in response to the tendency to slide down the

Rutherford County the general dip i s down stream in the gen

i rection of i s sa Of the branches Stones River , that to y, Stones

River follows a dip slope . In the extreme northeast corner of the county the top O f the Ridley limestone has an elevation O f 500 feet ;

760 800 D onnels 720 at Pinnacle Knob , ; at Fosterville , ; at Chapel , ;

630 600 o f 700 at Readyville , ; at Milton , ; hills north Lascassas , ; at

560 700. d Jefferson , ; and at Murfreesboro , The correspon ing eleva “ ” tion of the black shale can be determined by adding 500 feet to the above elevations . SM ALL F O LD S

N one The ashville dome is by no means a smooth , and the dip varies considerably from place t o place on account Of small folds and domes superimposed o n the larger one . In Rutherford County t no here are numerous undulations in the strata , which are especially

ticeab le O f w on th . in the middle the county , as sho n e geologic map The Murfreesboro and Pierce limestones come to the surface only where the tops O f the folds have been cut O ff by erosion . The maximum h O f 1 0 eight the folds is about 0 fee t . The Nashville pike crosses Stones River near the center O f a small dome about a mile and a half in diameter and 70 o r 80 feet D high . own the river from this place to M cFaddens Ford there is

f o f presented in the cli fs a series folds , anticlines and synclines , and

h as the river cut a gorge through them . Along the east fork o f Stones River from Jefferson to Lascassas r mi f ro nent d om es . o the e are five p d , and several smaller ones Six these d omes bring the Murfreesboro and Pierce limestones to the surface . ’ D f w At avis mill , near Je ferson , the strata are thro n into folds about

1 00 20 o f yards across and fee t high . West Walter Hill there is a dome about three miles in diameter and over 1 00 feet high . The river cuts across the northwestern flank , exposing 70 feet Of Murfreesboro

27 O f l limestone and feet o f Pierce . Two miles south Walter Hi l there

two 80 is a dome miles in diameter and over feet high , and another at Bettys Ford of about the same dimensions .

O f - Lascassas is at the center an inverted , boat shaped fold , a double

50 . plunging anticline , three miles long , two miles wide , and feet high

on N This anticline is the maj or axis of the ashville dome , but is 62 GEOLOGY O F RUTHERFORD COUNTY

nearly at right angles to it . The Lascassas anticline is of spec ial in terest because it is the Oldest fold known in the entire Central Basin , having been started in the Murfreesboro epoch . This phase o f the fold will be discussed in the next chapter . At the bridge Over Stones

“ one e 8 River , mile southw st Of Lascassas , the dip is southeast feet in 1 00; one -half mile farther west the dip is west about the same amount . Murfreesboro stands on the west flank Of an anticline six miles

s 70 o r 80 . long , three mile wide and feet high The largest subsidiary dome in the county is in the V icinity o f Marshall Knobs . It is about

i x s 1 00 . miles in diameter , and feet high Other small domes and

one o f anticlines occur at Florence , mile north Smyrna , at Kings Hill ,

O f . miles west Murfreesboro , at Hoovers , and at many other places The most conspicuous syncline or trough in the county extends

e from Stones River at the Franklin road southeast to Gum , a distanc It of . nine miles varies in width from one to three miles , and in depth 4 from 0 to 80 feet . Another syncline extends from Hickory Grove School ( one mile east of Sulphur Springs ) nearly due so uth to the 1 0 . N . u tw w 0 U . S ational Cemetery It is abo t o miles ide and feet

one 60 deep at the northern end , and mile wide and feet deep at its tw southern end . The o synclines just described are practically con tinuous O f with each other . Between the anticlines and on the flanks the small domes there are also small synclines . In is interesting to note that nearly all the grist mills in the county are located on the up s tream flanks of the domes . The greatest amount

Of fall Of the river is at these places . The domed structure raises the Pierce limestone s o that the eroding power of the water can act on i s it , and since the Pierce limestone is platy it much more easily

w . r e eroded a ay than the overlying , massive Ridley limestone The moval of the Pierce limestone leaves the Ridley standing in the form of f ' a cli f , over which the water falls .

FAULT S

two u t Only fa lts have been discovered in the county, bo h small , ’ Da ff two one at vis mill near Je erson , and the other miles south Of ’ Christiana . The fault at Davis mill has a vertical displacement of 20 feet . The fault line runs northwest and southeast and is appar ently less than half a mile long and it cannot be followed for any considerable distance on each side of the river on account of being

64 GEOLOGY O F RUTHERF ORD COUNTY

I CHAPTE R V .

GE OLOG IC HISTORY

Geologic history is an account o f events in the history Of the ear w w as revealed by the rocks hich were laid do n in past ages . The

their character , thickness , position with reference to each

sea th vation above level , and their fossil content, constitute ’ record , and it is the geologist s task to unravel the history particular region from the fragmentary record made and pres

by nature herself . Frequently the record of long periods is mi and then the history must be inferred from the rocks of some

region .

The amount of information to be derived from a study o f the is analogous to the information that may be gained about a

O f peoples by a study the ruins left by them , as for example ,

o r O f mounds , ruins Of cities like Herculaneum , the Pyramids

so Just as human history is divided into periods and epochs , also

geologic history divided into eras , periods , epochs , and ages .

An account O f the events which took place in the formation

the surface features Of Rutherford County , since the beginning

h as . Tertiary period , been given in Chapter III The present c will deal with the geologic history since the deposition of the

e of rocks up to the pres nt . The subdivisions geologic time are

on 3 0 page , and the strata deposited in the c I w been discussed in Chapter V . The rocks ere deposited in w al a nearly horizontal position in bodies Of salt ater , bays

c O f M exI C O w Atl conne ted with the Gulf , and sometimes ith the

and Pacific oceans .

b the Geologic time is not reckoned in years , ecause actua

in years in each period is not known . Geologic time is

long and to be thought Of in terms O f millions O f years . mated mainly by the number o f years it takes now for the

o f o f e in the sea a foot s diment , and mu

h as total thickness of the strata . It been to years for a foot o f limestone to GEOLOGIC HISTORY 65 more than a million years were required for the deposition Of the 900 feet Of strata to be seen in Rutherford County, and they probably were u formed more than years ago . While these fig res are by

m o f no means accurate , they will serve to show the im ense stretches time consumed in geologic processes .

ORDOVICIAN TIME

The Oldest rocks exposed in the county were deposited during the

of e Chaz an o r e . rly part Ordovician tim , in the y Stones River poch that time the seas covered large areas o f the North American

especially t o the east of the Mississippi Valley . The seas

ounded h and with low forms of life, bot plants animals , but there

IS was r or no indication that there a living thing on land , eithe plant anl m al , during the Ordovician period .

M urfreesb oro ep och

e is In the Murfr esboro epoch , that , the period of time during which

o f limestone was deposited , the water the inland

lime was deposited by organisms .

low lated with forms Of plants , and algae, whose

se the abundant fucoidal markings se en in the limestone .

s also corals , sponge , trilobites , ostracods , molluscs , and living in the sea which covered Rutherford County; As

s w t o and plant died their bodies were covered ith sof oze ,

now d the organic matter was preserved , and appears as bitumi us or oily matter which gives to the Murfreesboro limestone its color

( I p eculiar odor . The same conditions and relations Of land and se a must h ave per

c a of out the epo h , for the ch racter the rock is the same

70 e one Las through the f et Of formation , with exception “ At

of or cassas near the close the epoch , there was an island , this place

r the seashore , for the deposits are sandy, laminated , ripple

suncr acke d and , and were dry land part Of the time, at least h tides . We know that the area whic is now Rutherford County

70 f or was at least miles from land during the Murfreesboro epoch , in the Wells Creek basin the Stones River formation i s wanting .

Pi erce ep och

The Pierce epoch succeeded the Murfree sboro with no discernible

. sea e o r w w lapse Of time The bottom was rais d , the water ithdra n , 66 GEOLOGY O F RUTHERF ORD COUNTY

w al f or the water was much shallo er than it had been . The water

rnated t h l te be ween muddy and clear , causing thin layers Of s a e and n i Of limestone to be laid dow , and massive l mestone was formed in s ome places while shaly limestone was forming in others . The massive

O f beds granular limestones contain abundant fragments Of shells , which would indicate that the water in which they were laid down

as . w in motion , as in strong currents moving in one direction numerous rill and ripple -marks in the platy bed s indicate a sea bot

a tom affected by undertow and w ves .

f or The conditions for life were very favorable, animals , mainly

Bryozoa , flourished . The water was probably warm and suppli

. 23 28 of du food . Between and feet sediments were deposited ’ D un this short epoch . At avis mill , near Jefferson , there is a slight formity . R idley epoch f h At the beginning O the Ridley epoc the land sank abruptly, o f O ff the shallow water animals were killed , and conditions again almost exactly as they had been in the Murfreesboro th e rocks O f the two form ations are almost identical . The

200 - e . probably less than feet de p The sponge like animal , cerium sea ce h alo , formed colonies on the bottom and the p p ceras swam about in considerable numbers . Brachiopods L common inhabitants Of the sea of this epoch . ow forms were again present in considerable numb ers and their soft b O buried in the ooze and appear in the rocks as fucoids . Th matter buried in the ooze gave rise to 0i material prese nt in NO t sand was carried to this region by the curren s , but the amount of silic a in the limestone is furnished by the silicious sp s e picules pres nt . L eb anon epoch

- b The Lebanon epoch followed the Ridley wi thout any reak ,

h h ad s allow water conditions again returned , much as they the Pierce . Thin beds O f limestone and shale were laid

80 1 20 -m . e e depth Of to feet Rippl , rill and wav w O ater was shallow during most o f the epoch . S cleared and heavy beds Of pure GEOLOGIC HISTORY 67

. was throughout the epoch At times life abundant , ostracods Shaped like a navy bean lived in great numbers , and bryozoa and brachiopods

m . of Plectam bonites were also com on A Species brachiopod , , lived in enormous numbers at some times and in some places , and their t shells make a limestone wo feet thick . At other times other species

minant ones . U NRECORDE D INT ERVAL

At the close Of the Lebanon epoch the region that is now the Cen tral Basin was raised slightly above sea level , and some Of the Lebanon deposits were eroded away . In the Appalachian region as much as

e were laid in fe t Of Sediments , the Blount group , down in this

Cart ers ep och

At the beginning of the Carters o r Lowville epoch the region once

o f . c om more sank below the level the sea The water was clear , and

ar ativel 200 was ma p y deep , some feet , and land ny miles away from

e of this region , as Shown by the b ds nearly pure limestone with very

- e e . S ea was little land deriv d s diment The sparsely populated , and corals ( Co lumnaria and Tetraclium ) were practically the only animals

e present , and even plants were rare exc pting possibly bacteria and

- lime secreting algae . The unfavorable conditions for life were pos

s f or sibly due t o a lack O f food . These condition persisted a short

s sea e time , and toward the middle Of the epoch the becam more Shal low S O that the beds o f limestone were interrupted by the depositi on o f f o f thin films o mud . Toward the close the epoch the water was S O Shallow that the sediments were ripple- marked as they were laid

-m t o down . Beautiful fossil ripple arks may be seen at the p of the Carters limestone in front O f the schoolhouse at D onnels on the Brady ville pike . The Lowville sea was probably our most extensive Pal eozoic Sea . UNRE CORDE D IN TERVAL

At e the end Of the Carters epoch a large island , about the pres nt n N dimensions and positio Of the ashville dome , was raised slightly

. n above the sea NO great erosion o this island took place , the amount Of erosion being indicated by the vari ation in thickness O f the Car 55 95 . ters , from to feet The interval lasted during the remainder o f r 1 60 Black River time and the ea liest Trenton (Curdsville) , while feet Of Shale ( Decorah ) and limestone ( Plattville) were being de 68 GEOLOGY O F RUTHERFORD COUN TY

es New posited in Minn ota and Iowa , the Black River limestone Of

Y d . ork, and the Cur sville Of Kentucky The interval , though geologi

e of f o . cally short , is to be measured in scor s thousands years

H ermit age ep och

sea d Once more the covere this county, but the water was shallow and frequently muddy , for limestones and shales are interbedded . Fo r the first time Since the beginning O f the Ordovician the sediments e were sandy . The sedim nts were largely sand along the western Side

Of the county, and are progressively more calcareous east and west

" h f V T o . A from that line . e source the quartz sand is ery uncertain

" o r river coming from some region Of granitic rocks , possibly from some region where the St . Peters sandstone was exposed , evidently emptied into the Hermitage Se a near the western border Of the county .

Whether the source Of the sand was the Ozark region , the Wisconsin ,

r o the Appalachian region is undetermined . The most abundant form of life in the Hermitage sea was a

D alma ne lla e r tillis e brachiopod , f , although it seems to have be n

u . os rare in Rutherford Co nty Corals and bryozoa , gastropods and

r c o d C c lora t a s were also common. The small gastropod y lived in some l p aces in immense numbers , and the Shells , which were made Of

u are calci m phosphate , responsible for the beds of phosphate found in the Bigby and Hermitage formations Of Middle Tennessee . It is possible that the phosphatic sandstone Of the western side of i o f the county s Bigby . In that event the western half the county e 75 was dry land during the Hermitage poch , and feet Of silicious and shaly limestone was deposited Over the eastern half . Then in the

e s Bigby epoch conditions were revers d , the eastern half rose , the we t 75 r crn half sank , and feet Of shaly and phosphatic sandstone we e d - i a eposited there . Since the deposits in question are Sim lar , h ve the e same thickness , and occupy the same position with ref rence to the strata above and below , they are all here considered to be of Her mitage age . UNRECORDED INTERVAL An unrecorded interval Of Short duration occurred after the depo sition O f the Hermitage and is represented in Kentucky by the Wilmore

. l limestone The Nashville dome was again s ightly above sea level ,

the some erosion of the Hermitage took place , partly represented by

O f 40 70 uncon variation in thickness that formation , to feet , but the formity is not marked . GEOLOGIC HISTORY

B igb y ep och

The sea of the Bigby epoch was V ery shallow over most O f the shville of t ut dome , and part Ru herford County was o o f water

s . e , as indicated by, the ab ence Of the Bigby Sandstones ,

shales were deposited , many Of the beds are laminated

ed . Small gastropods whose shells were made o f cal

us m nu bers in some localities . Brachi

lso d sea inhabite the in favorable places . y probable that the Nashville dome was tilted downward i north and west dur ng the Bigby epoch , where the sedi

t unr were more calcareous and hicker . This would leave an e

a interval in that part of the county not covered by the se . The st interval is indicated by the absence Of the typical upper Bigby

ssils . in Rutherford County , excepting in two localities

Cannon ep och

n a The Bigby epoch passed directly into the Canno epoch , and p rt

the Bigby is included in the Cannon in this county . The Cannon is a complex one and includes several smaller epochs r epre

and n by the Flanagan , Perryville , Catheys , Cy thiana formations

er regions . At the beginning of the Cannon epoch the western

N was se a 1 00 O r Of the ashville dome above level , while feet

e Of limestone was being deposited on the eastern limb . Then 1 00 whole dome sank and the Catheys limestone , some feet thick,

e w k laid down . Again the w stern limb rose hile the eastern san

are another 1 00 feet O f limestones were deposited . These events 1 00 Catheys limestone in Maury County , zero to feet 00 feet thick along the western si de Of Ruth County and 3 00 feet of Cannon along the eastern Side Of the

Cannon sea was clear and abounded in all kinds O f inver "

animals and low forms Of plants . Fossils are abundant in the

’ of s . this age , the most conspicuous one being corals , pelecypods , stro ods p , and brachiopods .

UNRE CORDE D INTERVAL

O f s O f At the end the Cannon epoch , which was al o the end the

he o f N sea renton period , t whole the ashville dome rose above the

200 O f d remained above for a long time , while some feet shaly

s were deposited in the Cincinnati region . The land was not 70 GEOLOGY O F RUTHERFORD - COUNTY

ar sea f o r f above level , no great amount Of erosion took place dur this time . L eipers ep och A small embayment covered the northwestern corner Of

1 00 O f ford County during this epoch , while about feet shaly lime f was deposited . Animals similar to those o the Cannon epoch l in this bay in large numbers .

U N RE CORDE D INT ERVAL At the end of the Leipers epoch Rutherford County rose above

sea S O the the and remained for the remainder Of Ordovician period ,

of D and the whole the Silurian and evonian periods . This lost inter val e vi was vastly greater than those not d pre ously, and to be thought of in terms Of mi llions o f years rather than in tens or scores of thou

. sands Several thousand feet Of limestones , sandstones and shales were , deposited in other parts Of the Mississippi Valley and the Appala region during this interval . At several times during the Silurian period the s ea s o f N n urrounded the center the ashville dome, and duri g , epoch came as close as Maury and D avi dson counties . D evonian period the sea covered the southern and western the dome , but Rutherford and parts of the surrounding mained as an island during the two periods . The top Of

not 1 00 o r 200 sea was far. perhaps feet, above level during interval and the amount Of erosion was not great . Any Of surface were smoothed down S O that an almost plane surface sulted by the time the region again sank beneath the sea. During the long interval represented by the Silurian and De von periods great changes were taking place in the forms Of life in

a n se and o the land . Fishes were evolved in the Ordovician an 1 D . to prominence in evonian Amphibians , the first animals to

n D . dry la d , were evolved in the evonian The first plants that live on land also appeared in the D evonian . The record Of these 0 is not preserved in Rutherford County, but is preserved at many places . CARBONIFE ROU S TIME M IS S IS S IPPIA N PE R I OD The Mississippian period is represented in this county by depo f e ormed in the Chattanooga and Ft . Payne epochs . Several later p Of the Mississippian and Pennsylvanian periods have been

72 GEOLOGY O F RUTHERFORD COUNTY

SUB SE "UE NT EVE NT S

of n The geologic history Rutherford County Si ce the Ft . Payne

O f epoch has left no record in the form rock strata . The history can only be inferred by the present position Of the strata , and the record preserved in adj acent regions . D uring the remainder o f the Mississippian period and the Penn sy lvanian period the Nashville dome was completely under water

d O f e many times , and several hundre feet sandstones , shal s , limestones ,

e w es conglomerates , and som coal beds were laid do n . Th e beds were

700 o r 800 e at least fe t thick , for they are still preserved in Short

Mountain in Cannon County, and they may have been much thicker .

o r At some time during the late Pennsylvanian , possibly the Per

was mian period , the Central Basin area elevated above sea level and D it never has been below it Since . uring the Mesozoic era the agents o f weathering and erosion were at work removing the rocks previously laid down . Along in the early Cretaceous period the land O f Middle

Tennessee had been reduced to a featureless plain , vary ing from sea level at the Tennessee River to possibly 400 or 500 feet above sea

o f . level along the eastern Side the Cumberland Plateau This plain ,

e on b call d the Cretaceous peneplain , is still preserved the Cum erland

P O f b ut S O r lateau and the top Short Mountain , far as is known the e are no remnants o f it in the Central Basin o r on the Highland Rim .

Part o f the Cretaceous peneplain is still preserved in Wayne and .Law rence counties .

- of A In the Cretaceous period , at the time Of the re elevation the p

alachi an re- d p mountains , eastern and middle Tennessee were elevate o r w S O th e tipped toward the est , that Cretaceous peneplain was some feet above sea level in the region o f the Cumberland Plateau and sloped down to sea level toward the west t o ab out the present

o f location Of the Tennessee River . Then began another long period erosion o r peneplanation which lasted until the Eocene period of the D i Cenozoic era . uring this per od the Highland Rim peneplain was formed , and some Of the material resulting from the decay Of the Mississippian and Pennsylvanian rocks was carried by rivers westward and deposited in the sea which then covered we stern Tennesse e . The geologic history since the Eocene period which can be inferred from the present topography of the county and the Central Basin , has a lready been given in the chapter on Topographic History . E CHAPT R V I I .

N ATU RAL RE SOU RCE S

The principal natural resources Of Rutherford County, excepting e Soil , are limestone, phosphate rock , and mineral water . The county

o f no deposits great value which might bring it wealth , such as

clay or precious metals . The future prosperity Of the peo

as h as su county depends , it in the past , upon the soil , p with products made from limestone and the development

the deposits Of phosphate rock .

S OIL

The soil is by far the greatest natural asset the county possesses . f in ranks with the best Soil to be ound the whole State , but at pres

it is considerably run down and is producing less than one -half

be made to produce . One O f the purpo ses Of the geologic

f or county was to furnish a basis a study Of the soil , ents t o find ways t o increase its productivity and increase

n re under cultivation are now being carried o . A full oh th e soil and its needs will be published by the Agricultural e artm ent f p o the University of Tennessee .

B UILD ING ST ONE S

Limestones are being used at the present time in the county f o r

sonr s . y, curbing , walks , and other minor u es The Ridley limestone

“ f or r ou h sub adapted g masonry, abutments Of bridges ,

i

b uildin s and a . g simil r uses It is massive, has few bed

and trims easily into desirable Shapes . It is extremely

i s S O st weathering , but it hard and brittle that the cost

and working it into building stone is prohibitive . It

to some extent for monuments , and it makes an excellent

o f this purpose . Most Of the rock the central plain is of

m - con arters li estone, along the western side Of the county,

s o f e s ledge very whit , finely granular lime tone which looks like

le a and would take a polish . It would make beautiful building 74 GEOLOGY OF RUTHERFORD COUNTY

r o monumental stone, but the distance from the railroad and a m

use on s ket will preclude its any large cale . Rocks suitable f or curbing and Of the proper thickness occur monly in the Lebanon limestone . The thin Slabs o f this rock

f or i been used walks and flagg ng , but the use Of stone for curbing, h ging and walks is giving way to cement , whic is cheaper and b m The Her itage sandstone , which thick along the western border der innin p g, chimneys and monu

u . ses It will stand fire as well as freezing, and it works easily . Murfreesboro and Ridley limestones are not suitable for chimney s 0 fireplaces , because they are very dense , and upon heating they f 1 . o and Spall to pieces The granular , porous slabs the Lebanon stone are suitable for these purposes , because the n t n and do o break o heating . The sandy limestone

r is well adapted f o such uses also . None Of the lime or burn to lime in the moderate heat develop ed in chimneys , but those rocks should be selected which will not crack up “ ” - f fi re . beating and cooling . This kind o rock is called rock

R OAD MATE RIAL

e l The Ridley and Murfr esboro limestones , which are near y id

s f r tical in character , are extensively u ed in this county o road ing material . The rock quarries and crushes easily, and is

f or cheap . It nevertheless makes a poor macadam road two

S O first , it has little clay in it that it does not bind and make a

' S O it surface, and Second , it is brittle that rapidly grinds into

n . and is blow away By the uses Of road rollers , a top dressing

o r a suitable binder , such as asphalt , bitumen Oil , the Ridley Murfreesboro limestones would make smooth and durable pik The upper part of the Carters limestone is much better ada for building roads . It is very tough and contains some clay ,

- would make an excellent water bound macadam . Its however , make it more expensive to crush . It occurs only alon

S O i s borders Of the county, less accessible than the other rocks ti ne o d . The partially decayed Lebanon limestone is being used i parts Of the county f o r road mater al . It is composed Of

O f sh O V small . broken pieces rock , and can be NATURAL RESOURCES 75

e road at little expense . After the new road is used a little while ff becomes hard and smooth and stands tra ic well . This material is

and d especially around Lavergne, could be used in other

. not n e county It does occur in thick deposits , but i shee ts to a foot thick Over the surface Of the bed rock in glady

gravels have a limited use as road metal along the eastern

the county . The gravel consists mainly Of rounded pieces

washed down from the Ft . Payne forma

n O f hills , and broke fragments limestone and A y . fter it is packed down the gravel makes

. s rable road , even in wet weather The deposit of

gravel are very limited in quantity and distribution . The larg

deposit occurs two miles east of Big Springs .

LIM E AND CE M ENT

NO limestone is being burned into quicklime in Rutherford at the present time , because better lime can be shipped and sold for less h t an it can be produced in this county . Many years ago considerable l of e ime was burned in the county, but the scarcity fuel has caus d N l the industry _to be abandoned . O limestone which contains ess than 5 r - 9 per cent O f pure calcium carbonate makes a fi st class lime . The 1 analyses O f limes tones in this county are Shown on page 8 .

The Hermitage limestone h as been use d in some places f or mak in 1 869 f . . g hydraulic cement , as mentioned by Sa ford ( Geol Tenn , , p . Although Rutherford County is provided with an abundance of i s b e of this rock , it very improbable that it will ever any com mercial f or a of on value the m king cement , account Of the distance f of f rom coal , lack cheap transportation , and the competition O fered

y Portland cement , which is Of a better quality than any natural

draulic y cement . PH O SPHATE

There is in Rutherford County an area of about 1 5 square miles

Which contains rock phosphate O f probable cOmrnercial value . The phosphate occurs on the hills bordering the western Side O f the coun

t v Davi . y, from Eagle ille north to dson County It occurs here in the

Hermitage formation , which is largely a sandstone , in laminated lay

e ers a few inches to several feet thick . The amount pres nt cannot 76 GEOLOGY O F RUTHERFORD COUNTY be determined until a detailed survey is made and numerous pect holes sunk to determine the thickness . The deposits are “ ” the blanket kind , that is , they occur on fairly level benches phosphate is concentrated by the leaching away of the lime

t s h os was originally presen in the e rocks , and the calcium p p which is insoluble in water , is left behind .

o f Phosphate occurring in sandstone is usually a low grade , it I S probable that most O f the phosphate in this county i s of a quality . Eventually the low grade phosphate deposits will be

uahle . , but not until the high grade deposits are exhausted In to pay mining at the present time deposits Should contain at

50 o f per cent calcium phosphate . The following analyses were s elected samples and are therefore Of the highest grade to be

ected p from this locality .

W AT E R R E S OUR CE S

Much Of the water which falls as rain runs into the j oints

- s o f ew m o f sink holes, that there are very surface strea s , outside

v In N ri ers and larger streams , even wet weather . early every in the county excepting Stones River dries up in dry weather

f f o r ing an undersupply o water stock . The reason for this is

o f e d the rocks are so impervious that most the rainwat r runs .

. s to the rivers as soon as it falls The den e nature of the rock , l of O f of ack soil over large areas the county, and the loss the

' are lar e l ests which once covered the county, g y responsible for floods along the lower courses O f the branches o f Stones River w i f ever there s an unusually heavy rain . The loods are not destructiy e to property, and successful measures have been w to control them by the erection Of dams and j etties , hich i f w the lo Of the water .

whic The county is well supplied with ordinary springs , nish a considerable amount Of drinking water for people stock . The water which flows from most Of these Springs is inated in wet weather by surface water which fl

- Wh channels through sink holes and j oints in the rock . enever water from one Of these springs is muddy it is a sure indication

i c ontamin part Of the supply s from the surface, and it may be

- with typhoid o r other disease making bacteria . NATURAL RESOURCES

fl There are several springs in the county which ow sulphur water ,

w one one l o f the best kno n being at Sulphur Spring , mi e north Jef l f erson . su , and another four miles north Of Murfreesboro The ”

a . phur in the water is really gas , hydrogen sulphide The water is a pure , rock filtered water and no part Of it comes directly from

i s the surface . The sulphur gas derived from the decomposition Of iron pyrite with which the water comes in contact . Sulphur water has no particular medicinal value , and the curative properties as i s gned to it are due to the large quantity which is drunk , and the favorable conditions Of rest and pleasant surroundings which accom

O f pany the use the water .

Many wells , especially those where the water comes from the

us Lebanon limestone , give strong sulphur water . The sulphur is

uall O f . y in the form a gas , giving a white sulphur water Sometimes the water contains the partially decomposed iron sulphide, in which

f or or case the water is black , and unfit drinking any other domestic

use . Black sulphur water contains also sulphuric acid , iron sulphate

For and other substances which are poisonous to the human system . tunatel f ew of y very wells give this kind water , and in these cases the water can be made whol esome by filtering through a sand and crushed limestone filter . c The Pier e , Lebanon and Hermitage limestones are the main water l searin Th g formations in the county . e depth to water varies in dif f erent places , depending upon the depth beneath the surface Of the

-b earin r ck w water g o s . In general water i s struck any here within the central plain at a depth of 60 t o 90 feet . The water seeps along the bedding planes and the j oints , and it runs from these into the well . wa The rock is al ys as full o f water as the pore spaces will admit ,

e and dens rock , such as the Murfreesboro , Ridley and Carters lime t S s one , contains very little water . ometimes water may be Obtained

o f by blasting the bottom a well , which will crack the rock in every 1 00 direction and allow the water t o run in . In a well feet deep 25 50 o f in . from to pounds dynamite should be .used blasting Some

a times well strikes a real underground stream, which are very nu mer ous in this county, and the water in these wells will be muddy in r ainy weather and therefore contaminated with surface water . There is no method by which the depth and quantity o f water c beneath the surfa e can be accurately determined , excepting by drill

- ing . The depth beneath the surface of the water bearing beds of rock 78 GEOLOGY O F RUTHERFORD COUNTY can be approximately determined by one acquainted with the geology

o f i . w a reg on In general , the best rule to follo in attempting to find water is to select a convenient location for the well and to drill until water is struck . If the hole is dry it has struck no b edding planes In or j oints through which water can se ep . this case the best thing 25 50 to do is to shoot the well with a good charge Of dynamite , to

wi f or e direc pounds , which ll shatter the rock s veral yards in every tion and allow the water from a considerable distance to flow into the well .

The attempt t o locate a supply of ground water by means Of “ ” a peach tree Switch or other divining r od is not only useless but “ ” W foolish . Water itching is practiced by many people in this coun t no y, and by people in probably every state in the Union , and water

on has ever been located by this means , but the other hand great wrong “ is done to many people by Sincere but misguided water witches . They cause credulous people to drill one well after another in loca tions where there is no prospect o f striking water on account of the structure and character Of the rock .

C OAL , O IL AND GAS

e The Black Shale has been prospect d time after time for coal , b ut l always with no results except the loss Of labor . Black Sha e is no indication Of coal . Coal results from the accumulation Of

’ table matter in marshes . The Black Shale was deposited in a n sea e ant , salt water , and while organic matter is pr sent it il in the form of coal . Some gas and o are present in the Black especially where the Shale is preserved at considerable depths th th e surfac e . In this county the Shale occurs at the tops Of and any gas originally present has long Since escap ed . Some

O f can be distilled from the shale, but the cost recovering the Oil m ore than the Oil is worth .

In order f or Oil and gas to be present in the rocks in paying quantites at le ast" four conditions must be met " ( 1 ) there must be

f or 2 u e 3 a source the Oil , ( ) a porous strat m to act as a res rvoir , ( ) an impervious stratum above the porous one to hold the Oil in and

c n 4 of keep it from es api g , and ( ) the structure the rock must be such that the Oil from a considerable area will flow to the reservoir th and be accumulated ere .

80 GEOLOGY ' O F RUTHERFORD COUNTY

O f o r e blocks barite, heavy spar , are frequently s en , but the quantity is insufficient to pay mining . The mineral is worth from two to three

e on dollars a ton when load d the cars , and Since the barite could b e collected and hauled to the railroad for less than four or five d ol

ton i s b lars a , it O vious that the small deposits in this county are und present conditions Of no commercial value . LI M ESTONE SAM PLE S COLLECTED

D BY * N . D LIMESTO E SAMPLES COLLECTE ROLF A SCHOE ER .

A N ALY Z DR H ED B Y . N D . J I . D . I S .

L o c a tio n

ut one - a mi e sou h O f La er ne , h lf l t v g , m e 1 0 . s a L . R . St . C . on N . , y , ft pl , Le b anon limes tone ke s a on Pi t ti , s ample

30 1 5

le R e mes one 30 p , idl y li t St L C . . . At o er ea r e on N . v h d b idg , ' m f a le 8 t . R . at m e os s y il p t p , Ridley limes tone 28 1 7

u o C St L R . us s ou t n . . . y j t th of big i ron b ridge over Stones River at m e os rom N as le il p t f hvil , M urfreesb oro lim estone 1 0

* S ampl es w ere O btained by taking a s ucc es si on O f limes tone chip s from t he o om f h n b tt o t e l edge t o b e a alyzed .

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