Revised Chronostratigraphy of the Cambrian System in Subsurface Ohio

Loren E. Babcock1,2 and Mark T. Baranoski3 1School of Earth Sciences, The Ohio State University, Columbus, OH; 2Department of Geology, Lund University, Lund, Sweden; 3Ohio Department of Natural Resources, Division of Geological Survey, Columbus, OH

ABSTRACT STOP 2—Major tectonic elements affecting Cambrian deposition: STOP 3—Proposed lithostratigraphic columns for the Sauk NORTHERN OH, GENERAL DOMINANT LITHOLOGY WESTERN OH & NORTHERN OH & WESTERN LAKE ERIE NORTHEASTERN OH & CENTRAL EASTERN OH & SOUTHEASTERN OH & NORTHEASTERN KY & GEOGRAPHIC 6, 7, 10 7, 6, ADJACENT IN, KY, & MI SOUTHEASTERN MI & ADJACENT ONTARIO ADJACENT PA OH ADJACENT PA & WV ADJACENT KY & WV NORTHWESTERN WV LOCATION Limestone 8 3 sequence in the Ohio region (Baranoski, unpub. data, 2013). Cambrian STABLE CRATONIC SHELF (OHIO PLATFORM) ◆ Precambrian Provinces: Eastern Granite-Rhyolite, East Continent Rift Basin, Grenville. 4, 5, 6, 7 PROTO-ILLINOIS- BOWLING GREEN FINDLAY ARCH PROTO-APPALACHIAN BASIN Dolostone MICHIGAN BASIN FAULT AREA/ AKRON-SUFFIELD- NORTHERN ROME TECTONIC

SERIES ROME TROUGH SYSTEM STAGES

GRAPHIC Quartz arenite EASTERN CONTROL trilobites from deep subsurface diamond core are shown in respective ERATHEM GRENVILLE ÒFRONTÓ WASHINGTON HIGH TROUGH HIGH FEATURE BIOSTRATI- years) EONOTHEM LAURENTIAN In recent years, the search for new hydrocarbon reserves, some ◆ Waverly Arch, Ohio Platform, and Rome Trough. LAURENTIAN MAGNETIC LINEAMENT age in millions of

NUMERICAL TIME NUMERICAL Subarkose and dolostone SCALE (Ma=Model WAVERLY ARCH lithostratigraphic units. Numbers refer to illustrated specimens. SERIES GLOBAL of them in unconventional plays, and strata that could serve as ◆ Proto-Illinois-Michigan and proto-Appalachian Basins. ÒGull RiverÓ / Carntown unit of the Black River Group Dolomite ÒGlenwoodÓ shale / Wells Creek Formation Shale WHITE-

MIDDLE Shale, siltstone, sandstone, targets for CO2 sequestration have helped refocus attention on ROCKIAN dolomite, and limestone ? e a c Middle Run Formation arkose u r f y s Grenville Province, the Knox and pre-Knox (Proterozoic-Cambrian) stratigraphy of ORDOVICIAN t m i n f o r Kno o x u n c o igneous and metamorphics x unconformity surface K n LOWER IBEXIAN Beekmantown dolomite Eastern Granite-Rhyolite the Appalachian Basin region of North America. A consideration 487 ? ? ? ? Rose Run Rose Rose Run sandstone CORE DGS 3562 equivalents? Run ss Rose Run central to interpretation of the economic potential of Cambrian sandstone EXPLANATION T Conformable surface Clastic Cobble Pebble Granule Very coarse Coarse Medium Fine Very fine Silt Clay r e unnamed ss unnamed ss Correl- Depth Porosity e Correlative surface strata in the subsurface of eastern and midwestern North ation m Eau Claire Formation, Warren County, Ohio, Ohio Platform t GR MD RHOB p i Depth Sedimentary Depth Lithology e Discontinuity 2 core from 2,821 ft (860 m). ‘Cedaria’ woosteri, cephalon from (feet) features GAPI G/C3 (feet) KEY m Group Knox

Carbonate Rudstone Floatstone Boundstone Grainstone Packstone Wackestone Mudstone 0 200 2 3 a America is the age and facies relationships of these rocks. TREMPEALEAUN l o f l Unconformity Cedaria Zone (Guzhangian Stage). Length 13 mm. Ca v Vuggy e

f Dolomite Knox a o ? u d f Rip-up clasts Facies change/

UPPER ÒB-zoneÓ ÒB-zoneÓ ÒB-zoneÓ Historically, two problems have impaired our ability to discern Py d e lithostratigraphic extent Brecciated o g

f FURONGIAN st F l d f Nodular o i Unnamed sandstone/ f IAN m R Cambrian f Krysic ÒSt. PeterÓ sandstone age relationships of Cambrian strata in subsurface Ohio and Mount Simon Ss Irregular nodular iaÓ i sandstone r f t e FRANCON- n elvinia1 o Krysic ss e p f ? nc p Cross bedding aphelapsis- a o Basal arkose f Fr Kerbel C 3,000 3,000 3,000 Ò Kerbel Kerbel Member Irregular contact Kerbel Member S Maynardville Formation h n adjacent areas: (1) few biostratigraphic and other recognized Member Member S h a o SAUK Normal fault h ? Non-deposition ? a n Laminated i

PALEOZOIC Nolichucky Formation 9 1 h F unit F unit ? Non-deposition ? d SEQUENCE t 3

h IAN u n s h Wispy, irregular a ky Formationa tit oon f ? ? Thrust fault h m E unit E unit chronostratigraphic indicators; and (2) reliance on outmoded on d h DRESBACH- ti d Burrowed a r m e h or M a r y 497 ? F o v v h e s u i l l Deep burrow ir f D unit e v h a o D unit F h l o r C p s m time-stratigraphic models. With new information bearing on both h sd Soft sediment deformation u y a h a o t CAMBRIAN E k C unit C unit k i o h crepicephalus1 r h s y n Trilobite 1 P h cedaria u h 2 B unit h F Fracture d B unit F of these issues we are now able to take a few steps forward in sd G n o 3,100 3,100 3,100 1 a r h A unit m h G Glauconitic S a t h i o h n h f Feldspathic A unit Group Conasauga resolving the generalities of time-stratigraphic relationships in h SERIES 3 Mount Simon Mount Simon h tone 3,130 Bottom h Hematitic 1 ands Sandstone equivalents? on S Breaks in line indicate missing core Sim intervals. Ca Calcite nt Proterozoic ou the Cambrian of Ohio. Middle Run Fm M st Stylolite Rodgers- GR Gamma ray ville Shale3 GAPI Gamma ray units Shale MD Measured depth Rutledge Limestone3 RHOB Density The International Subcommission on Cambrian Stratigraphy G/C3 Grams per cubic inch Sandstone 507 ? Pumpkin Valley Shale3

3 3 4 (ISCS) has recommended a new global standard for Cambrian Paleogeography and proposed extension of the Waverly Arch during Mid- Rome Formation Mount Simon Sandstone in Ineos (BP Chemical) Class One site, Allen Shady Dolomite3 Cambrian time. Modiﬁ ed from Blakely (2010). ? Basal sandstone chronostratigraphic nomenclature that eliminates many of the SERIES 2 4 County, Ohio, Ohio Platform core from 3,035 ft (925 m). Incomplete, FOOTNOTES Nolichucky Formation, Aristech Class One site, Scioto County, Rome Formation, Mingo County, West Virginia, aloleista- 541 2

carella TERRENEUVIAN undetermined polymerid trilobite exoskeleton (1) recovered from the Mt. ? LOWER MIDDLE o z o i c u n c on N e o p r o t e r f o r m i t y s Modified from: Ohio, Ohio Platform core from 5,071 ft (1,556 m). Numerous Rome Trough deep well core from 17,906 ft (5,461 ambiguities surrounding the assignment of North American 1,000 u r f a c e Cambrian Simon Sandstone is consistent with an age of provisional Epoch 3 (probably (+/-) 1Babcock (1994) ptychopariid sclerites are preserved in the Nolichucky m). Alokistocarella, cranidium, suggesting a 2Donaldson and others (1988) Guzhangian). Lower left image is a CT (computerized tomography) scan by 3Ryder and others (1996) position of Cambrian Series 3. Width about 10 rock units to various regional “standards.” The global model 1,400 4Santos and others (2002) Formation and suggest a Furongian Series position. Width Ann Cook, Ohio State University. Length about 8 cm. (+/-) 5Lidiak and Hinze (1993) mm. Photo courtesy Alan Donaldson. 6Babcock and Peng (2007) about 12 mm. ation 7 subdivides the Cambrian into four series and 10 stages. Although Form Peng and others (2012) NEO/MESO- n Ru 8Lochman-Balk and Wilson (1958) PROTEROZOIC PROTEROZOIC e dl 9 id Sloss and others (1949) not all series/epochs and stages/ages of the Cambrian System/ M 10Babcock and others (2011) Period have not yet been deﬁ ned, those that have been ratiﬁ ed

can be correlated precisely in most areas of the world using STOP 4 REFERENCES CITED —Regional cross section showing redeﬁ ned Mt. Simon Sandstone thickness decreasing onto the Ohio Platform and multiple chronostratigraphic guides. Rome Trough high. Consistent thickness of the overlying Cambrian units emphasizes the stability and uniform subsidence of Babcock, L.E., 1994, Biostratigraphic signiﬁ cance and paleogeographic implications of Cambrian fossils from a So far, age relationships of Ohio’s subsurface strata are deep core, Warren County, Ohio: Journal of Paleontology, v. 68, no. 1, p. 24–30. the Ohio Platform. Stop 3 shows selected cores with trilobites associated with open hole electric logs. Isopach map of the Mt. Babcock, L.E., and Peng, S.C., 2007, Cambrian chronostratigraphy—Current state and future plans: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 254, p. 62–66. based mostly on trilobite biostratigraphy, meaning that heavy Simon Sandstone shows the eastern extent of the proto-Illinois-Michigan Basin and related contemporaneous features. Babcock, L.E., Robison, R.A., and Peng, S.C., 2011, Cambrian stage and series nomenclature of Laurentia and Modified from Sanford and Arnott, 2010 the developing global chronostratigraphic scale: Musuem of Northern Arizona Bulletin, v. 67, p. 12–26. reliance is placed on the chance discovery of recognizable Blakey, R.C., [2010], Paleogeography and geologic evolution of North America—North American Duff well A B C D E API #3404720011 paleogeographic maps, Late Cambrian (500 Ma): Colorado Plateau Geosystems, Inc., last accessed April 4, Regional map showing major tectonic features and deep-well and outcrop 2012, at . remains in drill cores. Based on available evidence, most, if 3414520212 3416560005 3400363691 3414760840 7800007162 Donaldson, A.C., Heald, M.T., and Warshauer, S.M., 1988, Cambrian rocks of the Rome trough in West locations for this poster, generalized paleogeography during Cambrian time, USS Chemical/US Steel 97 miles Ohio Geological Survey 79 miles BP Chemical 60 miles Ohio Geological Survey 80 miles Chatham Resources Ltd. not all, of Ohio’s subsurface Cambrian is limited to provisional and revised Waverly Arch. Virginia—Cores from Mingo and Wayne Counties, in Smosna, Richard, organizer, A walk through the Paleozoic of the Appalachian Basin—A core workshop presented at the American Association of Petroleum Geologists–Eastern Section Meeting, Charleston, W. Va., Sept. 13, 1988 [proceedings]: Appalachian Series/Epoch 3 through the Furongian Series/Epoch. A new, Correlation Depth Porosi t y Geological Society (imprint), p. 6–18. 10 Correlation Depth Por os ity GR MD NPHI Trenton Ls 020NONE 0 0.3NONE -0.1 GR MD SNP A to E Knox unconformity Janssens, Arie, 1973, Stratigraphy of Cambrian and Lower Ordovician rocks in Ohio: Ohio Division of Geological incomplete exoskeleton recovered from the Mt. Simon Formation 0200GAPI 3%0 0 dt core Stop 3 140us/ f 40 F Survey Bulletin 64, 197 p. CA LI(CA L) RHOB

base of Knox

4 9 N 616IN 2G/CC.0 3.0 GRDE

FOA, F1 to F5 markers Dolomite Lidiak, E.G., and Hinze, W.J., 1993, Grenville Province in the subsurface of eastern United States, in Reed,

I 0.2NONE 2000

- -

is consistent with an age of provisional Epoch 3 (probably N

N J.C., Bickford, M.E., Houston, R.S., Link, P.K., Rankin, D.W., Sims, P.K., and Van Schmus, W.R., eds.,

S Mt. Simon Ss

3900 I

I Wells Creek Fm. Precambrian

8 A

A unconf. Precambrian—Conterminous U.S.: Geological Society of America, The Geology of North America, v. C-2, p.

S S

B ASHTABULA

Guzhangian). The oldest, previously recognized trilobite, 1 B Correlation Depth Porosi t y I 353–365.

I 1600

WILLIAMS FULTON LUCAS

GEAUGA

7 7 GR MD NPHI OTTAWA LAKE

A A 13 WOOD TRUMBULL HENRY CUYAHOGA

4000 SANDUSKY Lochman-Balk, Christina, and Wilson, J.L., 1958, Cambrian biostratigraphy in North America: Journal of DEFIANCE

ERIE LORAIN

O 020GAPI 0 0.3v/ v -0.1

O PORTAGE

N 5 N Knox unconformity PAULDING HURON MEDINA SUMMIT SENECA

O PUTNAM O HANCOCK

B MAHONING B 14 15 CALI RHOB Paleontology, v. 32, no. 2, p. 312–350.

“Cedaria” woosteri, from the Eau Claire Formation, suggests VAN WERT

WYANDOT CRAWFORD RICHLAND ASHLAND A WAYNE

N 16

N ALLEN STARK COLUMBIANA

61IN 6 2 G/C3 3

H HARDIN I

3 I 1700

I O MERCER CARROLL

I I Peng, S.C., Babcock, L.E., and Cooper, R.A., 2012, The Cambrian System, in Gradstein, F.M., Ogg, J.G., and Ogg, I MARION

AUGLAIZE HOLMES

MORROW

PEF

Beekmantown dol. TUSCARAWAS 17 KNOX LOGAN UNION JEFFERSON SHELBY 25 4100 COSHOCTON 18 HARRISON

0 barn/ e 10 DELAWARE

E DARKE

L G., eds., A geologic time scale 2012: Elsevier, p. 629–632.

L 21 LICKING

RR H

27 H CHAMPAIGN

26 GUERNSEY

MIAMI an age of Epoch 3 (Guzhangian Age). Sclerites recovered from N BELMONT N MUSKINGUM DT MADISON FRANKLIN 2 EE CLARK

NOBLE Ryder, R.T., Repetski, J.E., and Harris, A.G., 1996, Stratigraphic framework of Cambrian and Ordovician rocks

FAIRFIELD PERRY L PREBLE L 28 140 US/ F 40 MONTGOMERY MONROE C 22 C

GREENE PICKAWAY

1800 MORGAN

DD A P FAYETTE

I I Core_GrnDn HOCKING WASHINGTON BUTLER WARREN in the central Appalachian basin from Fayette County, Ohio, to Botetourt County, Virginia: U.S. Geological CLINTON A ROSS LL L A 4200 ATHENS

2 Gm/cc 3 VINTON

the lower part of the Knox Dolomite, including Crepicephalus?, M

- HIGHLAND - D

HAMILTON G CLERMONT

G A 19 R MEIGS U R L U L PIKE Survey Miscellaneous Investigations Series Map I-2495, scale 1:530,000. 11 T F O 11 POTA JACKSON BROWN ADAMS GALLIA

I SCIOTO

OO I O O 12 0.001PPM 0.100 C A Rose Run ss. 24 A 1900 Sanford, B.V., and Arnott, R.W.C., 2010, Stratigraphic and structural framework of the Potsdam Group in eastern HH LAWRENCE Aphelaspis?, and Elvinia?, indicate that this part of the Knox is of THOR H PP T H SS T 4300 6 -0.018PPM 18.247 Ontario, western Quebec, and northern New York State: Geological Survey of Canada Bulletin 597, 84 p.

PP URAN CC Santos, J.O., Hartmann, L.A., McNaughton, N.J., Easton, R.M., Rea, R.G., and Potter, P.E., 2002, Sensitive high 4 O T T O -2.579PPM 6.901 AA Furongian age. FF II 23 2000 resolution ion microprobe (SHRIMP) detrital zircon geochronology provides new evidence for a hidden 20 -- II RR B RR 4400 MM OO 1800 Neoproterozoic foreland basin in the eastern Midwest, USA: Canadian Journal of Earth Sciences, v. 39, p. 11 PP 11 The northwest–southeast migration seismic line crosses a monadnock drilled into at the Duff well in Fayette County, Ohio. The line demonstrates the irregular paleotopography of the fault- H TT G H 1505–1515. UU Copper Ridge dol. 2100 O O controlled Precambrian unconformity surface. The seismic line shows locally thick Mt. Simon Sandstone and consistent subsidence of the Ohio Platform for the post-Mt. Simon reﬂ ectors, which Sloss, L.L., Krumbein, W.C., and Dapples, E.C., 1949, Integrated facies analysis, in Longwell, C.R., chairman, R 12 4500 T S A E SPU R 1900 M P Sedimentary facies in geologic history: Geological Society of America, Memoir 39, p. 91–123. ? ? U suggests regional stability of this portion of the Laurentian craton. See base map (at right) for approximate location of seismic line in Fayette County, Ohio. O 11 11 R PP R R R 0 50 miles 0 50 miles 2200

STOP 1 Knox Dolomite B-zone —Global chronostratigraphic chart for the Cambrian System. 0 100 kilometers 0 100 kilometers 4600 2000

2300 ESSEX COUNTY KENT COUNTY WAYNE HILLSDALE LENAWEE Proposed extension of the late Emergent Ohio Platform, proto-basins, and 4700 ERIE

ST. JOSEPH MONROE STOP 5—Conclusions: BRANCH 2100 N

Mesoproterozoic to Neoproterozoic Waverly major structural features. N Ashtabula

LAGRANGE Correlation Depth Porosi t y A 2400 A STEUBEN Lake Fulton Lucas CRAWFORD BZONE BASE GR MD NPHI ◆ Trilobites from deep diamond cores are central to interpretation Rome Trough high and reduced Waverly Arch acted as barriers, Arch and major structural features. Williams

4800

Correlation Depth Por os ity 020API 0 0.3V/ V -0.1 G 2200 G Ottawa

Wood Geauga

CA LI MD NEUT1958 NOBLE DEKALB I I Henry Cuyahoga 616IN 305.526CPS 1026.370 Defiance Erie RR EE of the economic potential (including energy resources, minerals, effectively controlling Mt. Simon and Conasauga deposition.

2500 D

Trumbull VENANG 0 U GR NPHI H Sandusky Lorain U MERCER KENT COUNTY 2100 H

CALHOUN WHITLEY 0 JACKSON WASHTENAW WAYNE 4900 3 C ALAMAZOO Explanation C 0150GAPI 0%.3 -0.1 Explanation Paulding Huron

ESSEX COUNTY 2300 ALLEN Portage E ST. JOSEPH C Medina Summit GR1958 PEF C Seneca and gas and ﬂ uid storage) of Cambrian strata in the subsurface The stable low relief Ohio Platform developed following Mt. Simon

1 Akron magnetic boundary Putnam ◆

BRANCH ERIE Hancock D 0150GAPI 0%.000 10.000 MONROE TINGTON I HILLSDALE LENAWEE I LAWRENCE 2 Coshocton zone 2600 Mahoning Area of exposed Proterozoic rocks RHOB WW A 3 Fort Wayne rift zone 2200 A Wyandot 0 BUTLER Van Wert V 5000

STEUBEN 2G/C3.000 3.000 E

Lake E Area of intertonguing facies and Mt. Simon equivalents 4 Grenville front geopotential boundary zone Ashland Lucas Ashtabula M Crawford Wayne CRAWFORD M deposition, the Eau Claire Formation, the upper portion of the LAGRANGE of eastern and midwestern North America, as well as the age and 2400 ADAMS Fulton Allen Stark R Williams R

5 Seneca geopotential anomaly 0

Ottawa LLD WELLS Richland Columbiana 0 NOBLE Geauga Area of zero Mt. Simon and exposed Proterozoic 0 1 L BEAVER DEKALB 50 L

6 Southwestern Ohio geopotential anomaly 0OHMM.200 2000.000 Marion

Cuyahoga Wood Auglaize Defiance 2700 HenrySandusky Erie BLACKFORD Y 7 Bowling Green Fault System Maynardville Fm. Mercer Hardin Y Carroll Proterozoic well locations

ITLEY Lorain Trumbull MERCER 2300 Holmes Hancock facies relationships of these rocks. Conasauga Group, and equivalents. It was dominated by mixed 8 Findlay Arch -

5100 3485 JAY - Morrow VENANGO A Paulding A ALLEGHENY Jefferson Portage ALLEN R Huron

Seneca 2500 R

Medina Summit 9 Chatham Sag Tuscarawas Proterozoic monadnock

Putnam Logan C Knox C

Hancock 10 Algonquin Arch Nolichucky Sh. 3524 Knox unconformity

LAWRENCE Shelby N HH

Mahoning N Union H

Eau Claire H 0 Coshocton Data point BUTLER 11 Rome Trough 0 Harrison siliciclastic-carbonate sediments across central Ohio and primarily Van Wert 1 ◆ A deeply eroded, tectonically complex Proterozoic surface 2800 RANDOLPH Wyandot Crawford Delaware

Ashland Brooke

Wayne Fm. 3564 DELAWARE I Darke I WELLS ADAMS Allen Stark 12 Rome Trough rift shoulder high 2400

Richland Columbiana Nolichucky marker Champaign Rome Trough fault system 5200 S

Hardin BEAVER 13 Middleburg fault system S 00 datum proposed Miami Licking Auglaize 0 2600 3604 Guernsey Ohio ACKFORD Mercer Marion 1 GG WASHINGTON Carroll Hancock 14 Akron fault system Holmes datum Maryville Fm. I Limit of Kerbel Mbr F5 I

Morrow S Belmont carbonates eastward. E S controlled or inﬂ uenced development of the Waverly Arch, Rome JAY Maryville tongue Sandusky fm. Jefferson ALLEGHENY 15 Suffield fault system HENRY Franklin Muskingum Marshall FAYETT Tuscarawas Clark Logan 3643 WAYNE HH Knox Western edge of thick carbonate ramp Shelby 16 Smith Twp. fault system 2900 100 Union GREENE

LAWARE Delaware Coshocton Harrison O I 2500 O I 17 Highlandtown fault system 00 Madison Brooke Montgomery RANDOLPH 5300 3683 4 Preble Noble Darke AA Eastern limit Eau Clair shale facies Champaign Fairfield WASHINGTON 18 Pittsburg-Washington cross-strike structural discontinuity Greene Trough, proto-Illinois-Michigan Basin, and proto-Appalachian Known Proterozoic monadnocks were completely buried by UNION Pickaway ◆ 2700 Monroe Miami Licking Ohio FAYETTE HENRY Guernsey 19 Cambridge cross-strike structural discontinuity F4 F4 20 Fayette Perry N Belmont Proterozoic N 0 GG Monongalia Overthickened Sandusky equivalents Franklin Muskingum Marshall FAYETTE Morgan WAYNE Clark 20 Burning Springs fault system HH Wetzel B Madison GREENE 3000 unconformity II B Montgomery 21 Killbuck structure Butler Marion Preble FRANKLIN Hocking Grenville magnetic trend Noble 2600 Tyler the end of the proposed Sandusky E unit deposition, marking a Fairfield Basin architecture, and deposition of the Sauk sequence in Ohio Warren Greene Monroe Clinton Washington Perry 22 Utica structure 5400 UNION Monongalia F3 FAYETTE Pickaway L Morgan 2800 L UU Fayette Wetzel 23 Plum Run Quarry fault system 1 Conasauga Group Conasauga F3 Ross Athens 0 Pleasants Ta yl or Marion RIPLEY 0 Butler Hocking 24 Fayette structure DEARBORN Harrison FRANKLIN Warren 1 Tyler Doddridge Clinton 5 Washington Hamilton Vinton 0 LL Highland 0 25 Anna-Champaign fault system Wood and surrounding region. previously unknown regional hiatus. Pleasants 3100 C-1 RIPLEY Ross Athens Ta yl or F2 Ritchie 2 Barbour 5 Harrison 26 Auglaize fault system 0 I Hamilton Vinton Doddridge Proposed B-1 2700 I Meigs 0 Highland Wood 5500 F2 Pike Jackson OO 3 Isopach map of the Mt. Simon Ritchie Approximate top of Mt. Simon 00 27 Logan fault system D Clermont DEARBORN Lewis Meigs 00 Barbour 2900 OHIO KENTON Wirt 0 Sandusky fm. BOONE Clermont Pike 35 BOONE Jackson 28 Delaware structure according to Janssens (1973) FERSON Brown Gilmer OHIO KENTON 0 Wirt Lewis The Mt. Simon Sandstone is not a regional “blanket sandstone” The proposed Sandusky Formation eliminates and clariﬁ es current 0 CAMPBELL Calhoun ◆ ◆ Brown 0 00 Gilmer 1 Upshur Sandstone showing a reduced Waverly 3 5 0 CAMPBELL 4 0 Calhoun F1 Adams Scioto 0 550 Upshur A SWITZERLAND HH SWITZERLAND Adams Scioto 3200 PENDLETONOO Gallia Mason Gallia Jackson RR GALLATIN Mason Granite-Rhyolite Province/East Continent Rift Basin F1 GALLATIN Jackson PENDLETON 0 2800 BRACKEN CARROLL BRACKEN 0 Roane CARROLL Arch, proto-Illinois-Michigan Basin GRANT 0 Braxton Randolph 5600 GRANT Roane Braxton MBLE 5 0 Grenville Province T Randolph MASON 0 T extending across Ohio into the Appalachian Basin, as traditionally sub-Knox correlation problems. Lawrence 0 5 3000 GG 0 6 IMBLE OWEN ROBERTSON LEWIS 0 MASON HENRY GREENUP 4 Putnam Extent of Waverly Arch Lawrence HARRISON Clay Webster Mt. Simon Ss. HENRY OWEN ROBERTSON development, and the emergence of GREENUP TT Cabell 0 LEWIS Putnam Webster Global chronostratigraphic chart for the Cambrian FLEMING BOYD 0 00 OO 0 UU Clay NICHOLAS 70 Interpreted boundary, trend, or fault C-2 HARRISON SCOTT 85 3300 00 0 Kanawha OO SHELBY CARTER 60 0 20 75 0 Nicholas FOA BOYD Cabell FRANKLIN BOURBON 00 0 Pocahontas B-2 FLEMING Cambrian fossil assemblages and proposed updated Cambrian 0 Normal fault Proterozoic mapped. Updated mapping demonstrates the presence of the ◆ 9 0 the Ohio Platform over the exposed ROWAN 1000 SHELBY NICHOLAS System compared to regional subdivisions used BATH Wayne Lincoln RRSCOTT Kanawha CARTERRR ENCER WOODFORD FAYETTE ELLIOTT 00 Small fault unconformity 3100 Nicholas MONTGOMERY LAWRENCE 0 FRANKLIN ANDERSON 95 50 Boone BOURBON CLARK 0 Fayette Pocahontas 1 00 0 50 miles P Proterozoic unconformity surface. 8 0 P TT JESSAMINE MENIFEE MORGAN 0 1 Greenbrier Data point ROWAN E E Wayne WASHINGTON 0 1 BATH Lincoln historically in Laurentia (left) and detailed 4000 0 Mt. Simon Ss. MERCER POWELL JOHNSON MARTIN Mingo Logan lithostratigraphy opens the way for further reﬁ nement multiple SPENCER Waverly Arch and emergent Ohio Platform. MADISON 0 Raleigh 100 kilometers 3400 FAYETTE EE GARRARD WOLFE ELLIOTT 500 MAGOFFIN 7000 Summers Rome Trough fault system WOODFORD MONTGOMERY LAWRENCE BOYLE 5500 ESTILL 0 FLOYD Wyoming OHIO PLATFORM ANDERSON Boone CLARKMM Fayette chronostratigraphic scale of provisional Series Knox to Proterozoic isopach, contour interval 500 feet Greenbrier ELSON JESSAMINE MENIFEE MM 3200 OO MORGAN MERCER JOHNSON Logan WASHINGTON MADISON POWELL OO MARTIN Mingo Raleigh Subsidence of the proto-Illinois-Michigan Basin during Mt. chronostratigraphic and lithostratigraphic methods to reduce risk ROME TROUGH WOLFE ◆ 3 (right) with trilobite zonation for Utah (for RR Summers BOYLERR GARRARD ESTILL MAGOFFIN FLOYD Wyoming 3500 comparison to Ohio). Both charts from Babcock and Isopach of Sauk sequence shows Cambrian- HIGH Contour interval (100 feet) 0 50 miles Contour interval (20 feet) Simon deposition was in part contemporaneous with Rome in predicting potential hydrocarbon and saline reservoirs. New others (2011). Early Ordovician extent of the emergent 0 100 kilometers Ohio Platform. Trough subsidence and lower Conasauga Group deposition. The information will help.