A Geologic _..~ a p of a Portion of the Bridge ?t' Quadrangle ,

Presented in Partial Fullfillment of the Requirements for the Bachel or of Science Degree in

Geo J ogy & ;< ineralogy at Th e Ohio State University 1983

Robert R. Beckwith

Thesis Advisor

Department of Geology & ~ inera l ogy i

Ai\E 0 NT,E DG :Sr-1EHT S

I woul d l ike to thank my a dvisor , Professor Russell O. Ut gard f or his assista n ce , concern , criti cism, editing , and time in the co ~pl etion of this report . I t was gr eatly appr eciated. I would als o like to thank the Wa llace Book and Sta tionery Co mp any of Oil City , Pennsylvania for supplying me with the 7 ~ ' topographic ma p s of the Co r nplanter Bridge Quadrangle . ii

TABLE OF CONTE?l\S

A ~GIO\'frJ EDGB:· ~ E~TT S •••••••••••••••••••••••••••••••••••••••••••• i TABLE OF FIGURES ••••••••••••••••••••••••••••••••••••••••• iii ABSTRACT••••••••••••••••••••••••••••••••••••••••••••••••••• 1 PURPOSE Af D I NTRODUCTION ••••••••••••••••••••••••••••••••••• 1

T OPO G~A FH Y ••••••••••••••••••••••••••••••••••••••••••••••••• 3 Drainage•••••••••••••••••••••••••••••••••••••••••3 Relief•••••••••••••••••••••••••••••••••••••••••••3 v u ~ - m s Ro cn. ill ••••••••••••••••••••••••••••••••••••••••••••••••• 3 DEVOJ'TI AN & i·-'!I SSI SSI PFI A T SY STE ,1 S ••••••••••••••••••••••••••• 5 Venango Formation••••••••••••••••••••••••••••••••5 Catskill Formation••••••••••••••••••••••••••••••• 5 Shenango- Oswayo Formations ••••••••••••••••••••••• 6 PEl,JN S y1 VA I'·T I Al.\ SY ST E/I ••••••••••••••••••••••••••••••••••••••• 6 Pottsville Group ••••••••••••••••••••••••••••••••• 6 Olean Formation••••••••••••••••••••••••••••••7 Sharon Forn1ation ••••••••••••••••••••••••••••• 7 Connoquenessing Fo r mation •••••••••••••••••••• 7 G ~Oj. O GIC HI STORY 8~ GE01·-10RPHOLOGY •••••••••• •••••• •••••••••••8 Preca~ brian Time•••••••••••••••••••••••••••••••••8 Cambrian Period••••••••••••••••••••••••••••••••••8 Ordovician Period••••••••••••••••••••••••••••••••8 Silurian Period••••••••••••••••••••••••••••••••••8 De vonian Period•••••••••••••••••••••••••••••••••• 9 I- i ssi ssippi an Period ••••••••••••••••••••••••••••• 9 Pennsylvanian Period•••••••••••••••••••••••••••• 10 rr esozoic & Tertiary Times ••••••••••••••••••••••• 10 Pleistocene & Recent Times •••••••••••••••••••••• 10 GEOLOGI C STRUC TURES ••••••••••••••••••••••••••••••••••••••• 11 REFERE(CES•••••••••••••••••••••••••••••••••••••••••••••••• 13 iii

TABLE OF FIGURES

GEOI .OGI C ~< A P •••••••• • •••••••••••••••••••••••••••• back cover LOCAT ION OF AREA ( fig . 1) ••••••••••••••••••••••••••••••••••2 PHY SI OGR APHI C PROVI 1'J CES 1;AP ( fig . 1 ) •••••••• • •••••••••••••• 2 GEOLOGI C COIJ U\:N (fig. 2) ••••••••••••••••••••••••••••••••••• 4 CR OSS SE CTI OIJ ( fig . 3 ) •••••••••••••••••••••••••••••••••••• 1 2 ABSTR ACT

The Cornplanter Bridge 7i' Quadrangle had not previously been ma pped by di rect methods , only indirectly from written reports. Utilizing pace and compass me thods, the Devonian, Eississippian, and Pennsylvanian formations were identified and the corresponding contacts were mapped. This report incl udes a geol ogic map of a portion of the quadrangle, a description of the rock units, topography, and geologic structures, and the geologic history and geomorphology of the region.

PUR POSE A1 D INTRODU C TIO~

The purpose of this report is to provide a more reliable geologic map of a portion of the Cornpl anter Bridge 7t' '< _.uadrang1 e , Pennsylvania. Plate 1 is t he area ma pped and is locate d south of t he Allegheny Reservoir and west of i n V·'arren and -_er ean Counties, 8 mi l es south of the State l~n e (see fig. 1) . Be tween August 10 and 20 , 1982 , this area was ma pped using pace and comp ass methods. Problems we re encountered in mapping because of the heavy vegetati on cover and by close similarities of some of the units. This area i s part of the Allegheny National Forest. Topographically, it is a maturely dissected plateau with numerous ridges and deep valleys. Th e broad ridges are held up by t he r esistant sandstones and congl omerates of the Pottsville Group and are sites of scenic overl ooks .

E d ~un d s in 1977 compi 1ed a geol ogic map based on a 1960 state compi l ation sheet and on a report by Lytle and Goth ( 1970) . The r eliabilit y of the contacts we r e noted a s being poor to fair and t he Venango-Catskill facies change was a pproximately l ocated and not based on detailed studies. ,\o'<' c:,eC. N\~c,t. '-°'"'"e ~v..0 Co r nplanter Bridge 7t ' Quadrangle ,e'<'<' ~\.._~Q ~oc, .,_\. \.o

1 ct.~~'- t4:..AH'--~------ll'()TTC P . \ ~ · -+ ·

N

PROVINCE

Figure I - Physiographic provinces map of Pennsylvania. 3

TOPOGR APHY

Drainage The Co r nplanter Bridge Quadrangl e l ies wi t hi n the Allegheny Pl ateau physiographi c province (see fig . 1) . The area is drained by the Al legheny River whi ch flows southwesterly a cross the northwest part of the quadrangle, and by t he Kinzua Creek which f l ows northwe sterly across the area. The Allegheny Reservoir was created wh en t he Kinzua Da rn was con­ structed in the early 1960 1 s across the . Th e dam is l ocated just west of the quadrangle ' s western border.

Relief The topography is that of a maturely dissected plateau. The surface is very hilly wi th many short r idges and s purs whi ch have no syst ematic orientation. The r idges are broad a nd comp aratively level on top . The main valleys are deep and narrow and are bounded by steep valls. The highest surface el eva t ion in t he area is 2 151 feet l ocated a pp r oJ~i rn ately on e mi l e south of Dewdrop Campg rounds. The lowest surface el evation is 1328 feet wh i ch is the normal elevation of the reservoir.

ROCK UNITS

For nations bel on ging to the De vonian , Mississippian , and Pennsylvanian Systems occur a t the surface of the Cornplanter Bridge Quadrangle and total a pproximately 800 feet in thick­ ness . Figur e 2 is a geologi c section near hill 2130 located 1. 25 mi l es west of Camp Cornplanter. 4

AGE FORMAT I ON COL UMN ELEV. DESCRI PTION z < zH < Pottsville > ~ Shale, gray to black, some coal >­en z Fp Conglomerate, well rounded pebbles z t&:l light gray with yellow staining a. Siltstone. 2rav with some coal Sandstone, conglomeratic, dis­ 1950 coidal shaped z Siltstone, dark-gray interbedded < ~~ . -=- . ;_--: H -·-·- With black shale a. a. :.·_.· .,:,·.:. ;." :.· . · . ~ - 1900 H en en Sandstone, coarse-grained, gray H en Shenango f--~i~i;~ 1850 Cf) Shale, dark-gray interbedded with H greenish-gray siltstone ::?!: through Sandstone, fine-grained, greenish­ Oswayo gray Shale, dark-gray

MD so Siltstone, greenish-gray r-·-·-·- 1650 Shale, dark greenish-gray

Shale, black interbedded with ~reenish-gray siltstone z < Sandstone, fine-grained, gray zH 0 It> ale, dark-red interbedded with > ~ 1500 olack shale 0 Catskill Sandstone, fine-grained, gray 1450 IS hale, red Dck Shale, dark-red interbedded with grav shale 1400 Shale, dark-red interbedded with black shale Venango Shale, black .:·::: ·:.::.:.··.:;:: :·:.;·:. 1350 .·.·· . . · i .···::·. - Sandstone, fine-grained, gray Dv Shale, dark-gray-to black

F.XPT .AN A'11 J 0 T

Conglomerate Siltstone

Sandstone Cross-bedded sandstone Shale

Figure 2. Ge ologic section near hill 2130. 5

DEV01JI Ai-J Ar D I ·· ~ ISSISSI FP I Ar SYSTEMS

In this area , a pproximately 680 feet of Upper Devonian and

~ ississippian rock s are exposed. In ascending order they are the Venango Formation (De vonian), Catskill Formation (Devonian) , and Oswayo through Shenango Formations (Devonian- Mississippian) .

Venango Formation This formation has been called the Cattaraugus Formation by Lytl e and other earlier workers. In this area, Socolow has defined the r ocks to be Venango. This formation averages a pproxima tel y 150 feet of exposure. The Allegheny Reservoir is the l ower limit of outcrop with its surface elevation of 1328 feet.

The r ock s consist of light gray sil tstones interbedded wi t h bl uish- gray shales and some flaggy gray sandstones. Beds of black sha l e occur throughout . Wher e the Venango interfingcr s wi t h the Catskill Formation , r ed shal es occur.

Catskill Formation This formation has been called the Cattaraugus and Oswayo Formations by earlier workers (Lohman, Lytle). So colow defined the rocks as belonging to the Catskill . I t ranges in thickness from 0 to 110 feet, thinning out towards the northwest until it disappears near Dewd rop Run .

These rocks include dark red shal e, siltstone, and s andstone with units of gray sandstone in the upper part. The litho­ logies in the upper part display upward fining cycles. 6

Shenango through Oswayo Formations

~ arlier \torkers have called these rocks the Pocono, Kn a pp , or Oswayo Formations. The United States Geologic Survey clas­

sifies these rocks to be Upper Devonian or ~ ississippian in age because no detailed study has been done to divide the ages into specific systems. These rocks include lateral equivalents of the Oswayo Formation , Cusewago Sandstone, Bradford Shale, Corry Sandstone, Cuyahoga Group, and the Shenango Formation .

These rocks consists of conglomeratic sandstone and medium­ grained sandstone and several beds of gray to black shales. Greenish- gray , olive, and buff sandstones also occur in vary­ ing a mounts .

Be fore the overlying Pennsylvanian rocks were deposited, the area was tilted southward and truncated by erosion. This un­ c onforxity causes a thickness variation from north to south. The thickness ranges froc 500 f eet in the southern part of the quadrangle to 320 feet just south of the reservoir in the northwest section.

PENJSYLVANIAN SYST EM

The Pottsville Group lies unconformably over the Mississippian strata. The average thickness is approximately 120 feet and the rocks of this group are preserved on the ridges. The Pottsville consists of the Olean, Sharon , and Connoquenessing Formations . 7

Olean Formation The Olean averag es a pproximatel y 50 feet in thi ck ness. It con s i sts of a coars e conglomerate of we ll rounded p ebbles of whi t e quartz ceme n ted i n a sandston e matrix. These p ebbles are stained a yellowish- brown and are more rounded than the disc- shap ed pebbles of the underlyi ng Shenango Formation .

Sharon Formation The Sharon Formation consists of a dark fissle shale inter­ bedded with very t hin coal and sandstone l ayers. This form­ ation averag es a pproximately 30 feet in thickness .

Connoquenessing Formation The youngest rock s in this area bel ong to this formation. These rock s are coarse- g raine d quartz san dstones with thin l ayers of conglomerates . This sandston e forms the rimrock of the valleys occupied by t h e Alleg heny River a n d Kinzua Cr eek . This f or mation has a n average t hi ck n e ss of a bout 40 f eet . The dep osits abov e the Co nnoqu ene ssing have been en­ t i r ely er oded awa y . 8

GEOLOGI C HI STORY AND GEO MORPHOLOGY

Precambrian 7 ime Rock s of Precambrian age are not exp osed in the area, but in southeastern Pennsylvania , schists, gneisses, and granites overlain by lavas are exposed. These form the surface on which the Pa l eozoic sediments were deposited after a consider­ able time of erosion took place.

Cambrian Period Most of Pennsylvania was beneath sea level during this period and conglomerates , sandstones, and shales were deposit­ ed. Several sedimentary changes took place allowing for thick sequences of limestones and dolomites to alternate with thin­ ner beds of elastic sediments. These rocks are not exposect in the region.

Ordovician P eri od A t hick series of l i mestones and dol omites were deposited during this time due to a continued widespread submergence and is believed to underlie the entire area although rocks of this age are not exp osed. Several temp orary e mergences of lan d are recorded in the south-central part of the state in which shal es and sandstones were deposited to the north .

Silurian Period The Sil urian began with emergence from the southeast which resulted in a widespread deposition of pure quartz sand. Thi s sand formed the hard Tuscarora quartzite . Later sub­ mergences resulted in the deposition of more sands, muds , and limestones . No rocks of this age are exposed in the area. 9

De vonian Period This p eriod began with the deposition of the Helderberg Limestone fo l lowed by the deposition of the c hert , sili­ ceous limestone , and calcareous sandstone of the Oriskany Group. The succeeding Onondaga period resulted with the deposition of shale and limestone. A thick series of sand­ stones, shales, and limestones were deposited in shallow water after Onondaga time during a long period of slow and constant subsidence.The deposition of the interfingering deltaic Catskill Formation began in eastern New York while the deposition of red shales and sandstones continued con­ temporaneously with the marine Portage and Chemung sediments.

These extended into early ~ ississippian time , in which the stratigraphic position rose progressively westward. This caused the Catskill to diminish in thickness from east to west . In this map area, the dominatel y red beds above the Chemung are known as the Venango For mation which inter­ fing ers with t h e Catsk i ll Formation . The Venango was over­ lain by the deposition of greenish- gray shal es and san dstones of the Oswayo Formation.

Mississippian Period The deposition of nonmarine and marine sands began the Missi ssippian. The age of the eastern and wester n equivalents

in the state are not known so that the ~ississippian ­ Devonian Periods are combined to include the Shenango Formation, Cuyahoga Group , Corry Sandstone, Bradford Shale, Cusewago Sandstone , and the Oswayo Formation.

These de posits were succeeded by the red beds of the Aauch

Chunk Shale . The ~ au c h Chunk is several thousand feet thick in northeastern Pennsylvania, diminishing to less than 100 feet in the northwestern part of the state , and is absent i n some places . This would indicate that most of the area west of the Alle gheny Front was uplifted and tilted south­ ward. Th e ~ auc h Chunk was largel y eroded before the de posi­ tion of t h e Pottsville Group . 10

Pennsylvanian Period

The rock s of this period lay unconformabl y on the ~ississi pp ian strata. During Pottsville t ime , about 1 , 000 feet of congl om­ erates a n d sandstones containing coal beds were deposited in eastern Pennsylvania while about 10, 000 feet were laid down in Alabama . North- central and western Pennsylvania we re we l l above sea level while these sediments were being dep osited. Near the end of the Pottsville , the land submerged and the Ol ean Co nglomerate , Sharqn Shale , Connoquenessing Sandstone , Merc er Shale , and c oal members were deposited. I n this area, a ll the s trata above the Connoquenessing has been removed by erosion .

The following Allegheny time resulted in the deposition of shal es , sandstones , limestones , and coal due to rapidl y a lter nating condi t ions . This formation contains most of the c oals mined in this part of the state. These c oal s were f or med in fr esh ~ate r ma r shes near sea level a nd extended ov e r t housards of squar e mi les . Further deposition o f lime­ stones , s hales , a nd sandst ones of the Conemaugh , :ononga hela , and Dunkar d ( Per mian) Formations followed. These contain thin layer s of coal t hroughout .

i·1esozoi c and Tertiary Ti mes The Appalachian u plift near the end of the Pa l eozoic term­ i nated the sedio entation in the area. Afterwards , the history was one of continued erorion and subsequent uplifts.

Pleistocene and Re cent Ti mes Glacial rr elt water s played a major r ole i n t h e f or mation of t he present t op ography although the c o~tinental ice sheets did not extend into the Cornplanter Br idge area. The "liscon s in i c e sheet a dvan c ed to just off t he northwest corner of the quadrangle (see f i.c . 1 ) • 1 1

The Kinzua Da IT s i te i s t h e l ocation of a pre- gl acial di vide . CTh e n the nor th- f l owing streams were damme d, the water rose un t il i t f l oTi e d over t he divide, ero ding i t compl etel y away. The r esulting All e gheny River Valley has been f illed with til l , s ilt, outwash and moraine deposits . These glacial dep osits have been continuously eroded and are now covered by the AlJ egheny Reservoir.

G ~OLOG I C STRU CTURES

1r he Cornplanter Bridge Quadrangle l ies structurally in the state's northern part of t he Appalachian Plateau province. The fol ds and faul ts of the Valley and Ridg e province to the southeast diminish in magnitude towards the northwest into this area. The region a l dip is about 22 feet p er mile to t he s outh east. Figure 3 is a cross section of the area showing the Fennsyl vanian - ~ 1 ississ i ppi an unc on formity, r egiona l dip , and t he Catskill tongue inter fingering wi t h t he Vena ngo Forn.a tion . CROSS SECTION THROUGH LINE A-A'

!

A A'

fp 2000 1600 1200 Dv· D~

SCALE ~~~.-a-i-i~,~~2~~~o_o~~~~--4j00 feet

1:24000

EXPLANATION

~~ ( Dck j Pottsville Catskill Group Formation

~~ I Dv Figure 3. Cross section Shenango- Oswayo Venango Formations Formation 13

REFEREN CES

E d ~ unds , W. E., ( 1977) , Atlas of Preliminary Geologi c Quadrangl e ~ a p s of Pennsylvania , Pennsylvania Geologic Survey , 1981 .

Lohman, S . W., 1939 , Groundwater in \ orth-Central Pennsylvania, Pennsylvania Ge ologic Survey, Fourth Series, Bulletin W6 , p . 22- 34 .

Lytle , w.s., 1965, Oil and Gas Geoloey of the Varren Quad­ rangle , Pennsylvania Mineral Re sources Report M52 .

Lytle, w.s., Goth , J . H., ( 1968) , Oil and Gas Geology of the Kinzua Quadrangle, Pennsylvania Mineral Resources Report ~ 62 , 1970 .

Me ckel , l,. D., 1964 , Pottsville Cong l o~erate of Pennsylvania: Paleocurrents and Grigin , American Association of Petroleum Geologists , no . 48 , vol . 4, p . 538 .

So col ow, A.A., 1980 , Geologic i1aps of Pennsylvania, Department of En viromental Resources , Topographic and Geologic Survey.