Th ickness and extent of saline Cambrian reservoirs in the Ohio region are partially Mark T. Baranoski, Ohio Geological Survey controlled by the underpinning Precambrian complex and paleotopography
ABSTRACT Stop 2. Revised Sub-Knox nomenclature is based on continuous cores tied to electric logs. Stop 3. Base map showing Mt. Simon isopach and extent Charts show lithostratigraphic characteristics, proposed stratigraphic model, and revised nomenclature for the Sauk Sequence units in with selected electric logs with density cutoff s. Updated maps of the Precambrian complex (Granite system. Th e redefi ned Mt. Simon pinches out along Ohio and the surrounding region. Relatively short electric logs demonstrate Precam- Rhyolite and Grenville Provinces and the East Con- the northern portion of this arch. Along the south- brian paleotopography. Note absence of electric CHART SHOWING MEGASCOPIC, PETROGRAPHIC, AND ELECTROFACIES CHARACTERISTICS OF THE OHIO SAUK SEQUENCE LITHOSTRATIGRAPHIC UNITS tinent Rift Basin) unconformity surface in the Ohio ern portion of this trend, the Mt. Simon thickness Relative electrofacies geophysical log response (estimated mean value) X-ray diffraction of samples from selected wells Thin section point count A = Aristech well; P = Power well log data where Mt. Simon is not present. BP = Lima core; CWM = DGS Seneca Co. core 9
gamma ray units = density units = spectrometer units = photoelectric carbonate clay carbonate clay region are essential when selecting potential sites for thins to the east, grading laterally with mixed clastic- Unit name Generalized lithology and bedding API relative natural calculated grams/cc API % K relative quartz feldspar others quartz feldspar anhydrite others units = barns (dol.+ cal.) minerals (dol.+ cal.) minerals radiation relative to fresh water presence to K, Ra, Th CO2 sequestration into saline Cambrian reservoirs. carbonate Conasauga Group facies. An ENE-trend- Knox Dolomite dolostone—light to medium to dark gray; low high medium na 1% BP 1% BP 95% BP 3% BP na na na na na na na massive to medium bedded; locally, vuggy, 7 glauconitic, arenaceous, shaley, wispy to Regional structural features and paleotopography ing shoulder of the Rome Trough formed another laminated, nodular, rip up clasts Conasauga Group, dolostone and limestone—light to medium low to medium medium to high medium na na na na na na na na na na na na Maynardville gray; thin to medium and wispy bedded; locally, controlled depositional facies and basin architecture regionally extensive paleotopographic barrier to Mt. Formation glauconitic, arenaceous, nodular, rip up clasts Conasauga Group, shale and dolostone—medium to dark gray to high low low to na na na na na na na na na na na na of the proto Illinois-Michigan and Appalachian Ba- Simon deposition. Following Mt. Simon deposition, Nolichucky black; laminated to interbedded, to thin to medium Formation medium and wispy bedded; locally, fossilferous, glauconitic, arenaceous sins and Rome Trough. Th ickness and extent of po- the stable Ohio Platform developed, which was dom- Conasauga Group, dolostone—light to medium gray; thin to low high medium na na na na na na na na na na na na Maryville Formation medium to massive bedded; locally, bioturbation, glauconitic, arenaceous, nodular, 3 tential Cambrian reservoirs have been redefi ned with inated by cyclical mixed clastic-carbonate sediments anhydrite, rip up clasts Sandusky Formation quartz arenite to subarkose to siltstone to medium to high low to medium medium na 24% DGS 30% DGS 42% DGS 1% DGS 3% apatite, 28.8% A 33% A 28.8% A .5% A .8% A na (proposed dolostone—variable color: light to medium gray (cyclical response) (cyclical response) (cyclical glauconite, 20.7% P 37.8% P 32.3% P 4.63% P 2.1% P updated regional correlations and maps of Cambrian of the Eau Claire Formation and Conasauga Group. new name) to pinkish gray to dark gray to light brown to response) pyrite DGS reddish brown to white; interbedded to thin to medium to massive to wispy to cross bedded; sub-Knox units for the Ohio region. Th e Mt. Simon Th e redefi ned sub-Knox of the Ohio region illustrates cyclical; bioturbation; feldspathic, arenaceous to dolomitic; locally pelloidal; glauconitic, paleosols, shaley, anhydrite, rip up clasts Sandstone was deposited in an area limited to west- that the Mt. Simon is not the regional basal “blanket Eau Claire Formation quartz arenite to subarkose, shale, siltstone, medium to high low to high medium high .025 to .098 46% BP 36% BP 10% BP 8% BP na na na na na na na dolostone and limestone—variable color: light (cyclical response) (cyclical (cyclical units (mean .065) to medium gray to pinkish gray to dark gray to 40 to 190 API units response) response) 4.0 BP ern Ohio and the adjacent proto Illinois-Michigan sandstone” as traditionally mapped. Th e term San- light brown to reddish brown to white; (mean 140) BP 2.25 to 2.75 to 4.9 units interbedded to thin to medium to massive to units (mean (mean 3.5) BP A 7 wispy to cross bedded; cyclical; bioturbation; 2.55) BP T q Basin. Th e eastern limit of the Mt. Simon is redefi ned dusky Formation is introduced to clear up correlation glauconitic, rip up clasts T Mount Simon quartz arenite—white to light gray to red to low to medium low to medium 2.45 low 1.8 to 2.2 low .05 to .04 units 86% BP 10% BP na 4% BP na na na na na na na Sandstone upper purple; medium to massive to cross bedded; 20 to 100 API unit to 2.60 units units (mean (mean .065) BP 9 along a broad NNW-trending Precambrian paleoto- problems with the Mt. Simon, Eau Claire, and Co- bioturbation, rip up clasts (mean 50) BP (mean 2.5) BP 2.0) BP Mount Simon quartz arenite to arkose to shale, siltstone— medium (cyclical low to medium low to medium low to medium .01 to 86% BP 10% BP na 4% BP na na na na na na na Sandstone lower white to light gray to red; interbedded to thin to response) 40 to (cyclical response) (cyclical .06 units (mean .045) 7 W WV pographic arch (exposed Laurentian craton), which nasauga. Th e redefi ned units will aff ect mapping of medium to massive to wispy to cross bedded; 140 API units 2.45 to 2.60 units response) BP 7 locally conglomeratic, cyclical, bioturbation, (mean 90) BP (mean 2.5) BP 2.0 to 3.0 units rip up clasts (mean 2.5) BP extends in the subsurface from an area north of present potential reservoirs and show that the thickest, best- basal arkose quartz arenite to arkose to shale, siltstone— high low to high na na na na na na na na na na na na na white to light gray to red; interbedded to thin to medium to massive to wispy to cross bedded; Histogram showing the gross mineralogy day western Lake Erie, southward to the Ohio River, developed reservoirs are located below the 2,500 foot locally conglomeratic, cyclical, bioturbation, rip up clasts of Mt. Simon, Eau Claire and Sandusky from and the northwestern Rome Trough boundary fault minimum depth required for CO2 sequestration. Precambrian highly variable—quartz, arenite, granite, variable variable variable na na na na na na na na na na na na rhyolite, gabbro, schist, mnarble, diorite, amphibolite, granodorite, anorthosite XRD and point counts using core data from BP Chemicals (1991) and Heald and Baker (1977). Data is useful for a empirical compar- Chart shows distinguishing characteristics of the Sauk Sequence units in Ohio. Previous workers have inconsistently carried Up- ison of quartz dominated Mt. Simon on the per Mississippi Valley and southern Central Appalachian Basin surface nomenclature into the Ohio subsurface with deep test wells. Stop 1. Major tectonic elements aff ecting Cambrian deposition. west and mixed clastic/carbonate of the Eau Note the petrographic and geophysical log similarity of the Sandusky and Eau Claire Formations, which is in contrast with the Mt. • Precambrian Provinces: Eastern Granite Rhyolite, East Continent Rift Basin, Grenville Claire and Sandusky across the state. Simon. • Ohio Platform, Rome Trough and Rome Trough High 9 • Proto Illinois-Michigan and Appalachian Basins A T T Y TA AT AT T W AY A A A A A A A A AU T A A AK U T T U V Ò TÓ WA T T U 9 A A T A T TA Y T T Q W T & T & W T AK T A T & T A A T & UT A T & T A T KY & A JA T KY & UT A T & A JA T TA A JA T A A JA T A & WV A JA T KY & WV T W T WV Ò Ó A W K W T K A 3 ?
AZYA V A K
W A A A ? ? ? q A AT 3 Chart shows Sauk Sequence Ohio nomen- clature modifi ed from Janssens, 1973. T K
T A AU U K ? Ò Ó 3 A
A Ò Ó ? ÒK Ó
K Ò Ó Ò Ó
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T T K
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3 3 30 S T Magnetic anomaly map shows changes in relative magnetic intensity T along tectonic boundaries and structural trends. BP chemical industrial waste injection/stratigraphic test well. Den- T ? ? J q ? sity cutoff (RHOB 2.68 ~0%, 2.55 ~8%, 2.40 ~16%), uncorrected for View of the Laurentian craton during Middle Cambrian time. T Exposed craton on southern Laurentia, including shelf, follows complex lithology. PE (photoelectric) cutoff set at 2.4 barnes units. Rome Trough failed rift adjacent to Ohio’s southern state outline. Calhoun Jackson Washtenaw Wayne V Ontario Lake Erie Branch Hillsdale Lenawee Monroe Green outline is future extent of the Paleozoic Appalachian Ba- Erie ? Michigan Canada Crawford sin on the craton margin. Image modifi ed from Blakely, 2006. Steuben United States W 36 De Kalb Y Mercer Y Y Mid Continent EGR Rift System Allen Pennsylvania Butler Lawrence Indiana Y Y Wells Adams EGR Paleo-shoreline Beaver
Paleo-shoreline Paleo-shoreline Laurentian Laurentian Allegheny Craton Craton Jay
Y
ck o nc Ha Paleo-shoreline Paleo-shoreline Washington EGR Randolph T Z
Y Brooke Grenville Domains Laurentian Craton Ohio T Z Wayne High Greene Y Y Marshall Y East Continent T T Union Wetzel Rift Basin Proto-Illinois/Michigan Basin Trough Proto-Illinois/Michigan Basin Fayette Y West Virginia Monongalia Trough Trough Trough Marion Tyler Rome Franklin Rome LCM Rome LCM Rome LCM 99 Pleasants Wood Ritchie Dearborn Doddridge Proto-Appalachian Basin Proto-Appalachian Basin Ripley LCM Electric log from Seneca Co., Ohio (APINO Wirt Campbell Early Cambrian Rome Trough time Latest Middle Cambrian Mt. Simon time Late Cambrian Sandusky time EGR Ohio Boone Mason Jackson Calhoun 3414760840) showing gamma ray and neu- Chart shows proposed stratigraphic model and revised nomenclature for the Sauk Sequence units in Ohio. Th e Sandusky For- Switzerland Kenton Roane Gallatin Kentucky Grant Lewis Carroll Mason mation is introduced to eliminate and clarify correlation problems with the sub-Knox. Previous Mt. Simon correlations across the Bracken Pendleton Putnam Paleogeography and major tectonic features of the Ohio region during Cambrian time. Rome Trough subsidence decreasing by the tron signatures characteristic of Cambrian Owen Henry Robertson Harrison Fleming Carter Greenup Cabell Ohio Platform region are revised from the top of the Sandusky F2 marker on the cross section in Stop 4. Nicholas Boyd COUNTY end of Sandusky time. Note shrinking area of exposed Laurentian craton during Cambrian marine transgression and complete burial Knox and deeper for northern Ohio. Location Wayne Lincoln Bath Rowan Lawrence of Precambrian monadnocks in Ohio region by the end of Sandusky time. of the well is at point A on Stop 3 base map. Elliott INDEX OHIO GEOLOGICAL SURVEY, 2045 MORSE ROAD, BUILDING C, COLUMBUS, OH 43229 • [email protected] • 614-265-6586 Th ickness and extent of saline Cambrian reservoirs in the Ohio region are partially Mark T. Baranoski, Ohio Geological Survey controlled by the underpinning Precambrian complex and paleotopography
Stop 4. Regional cross-section tied to con- Stop 6. Computer contoured map showing portion of the Conasauga Group/Sandusky Formation and net footage for density log cutoff CONCLUSIONS tinuous core shows redefi ned Mt. ≥2.55 g/cc about 8% porosity for F5 marker to base of Sandusky interval. Red spectral shading is set at 200 feet to enhance thickest Simon Sandstone. Th ickness of the higher potential saline reservoir areas. Selected density logs and major facies boundaries representing the eastern extent of the Eau • A deeply eroded, tectonically complex Precambrian surface controlled de- • Mapping of density log cutoff values confi rms the required 2,500-foot Mt. Simon decreases onto the Ohio Claire Formation and extensive Conasauga carbonate platform are also shown. Map confi rms the required 2,500 foot depth for po- velopment of the Rome Trough, proto Illinois-Michigan & Appalachian depth for potential saline reservoirs of Mt. Simon Sandstone and San- Platform. Consistent thickness of the tential saline reservoirs of Mt. Simon and Sandusky Formation across the Ohio Region. Contours outside of closed 2,500 feet lines Basin architecture, and deposition of the Sauk Sequence in Ohio and sur- dusky Formation where present and major facies boundaries cross the overlying Cambrian units identifi es for the F5 marker and base of Knox Dolomite markers indicate potential reservoir areas for the Kerbel Formation, where present. rounding region. Ohio region. Potential saline reservoirs within the Kerbel Formation may potential saline reservoirs and empha- exist where developed below the 2,500-foot depth. sizes the stability and uniform sub- • Th e Mt. Simon is not a regional “blanket sandstone” extending across sidence of the Ohio Platform. Th e F2 Ohio into the Appalachian basin as traditionally mapped. • Incised valleys into the Precambrian surface are known in Jackson and marker beds partially correlate with Fayette Counties, Ohio. However, the number and extent of potential previously defi ned Mt. Simon. See • Subsidence of proto Illinois-Michigan Basin during Mt. Simon deposition reservoirs within incised valleys across the Ohio region is unknown. Al- base map (Stop 3) for approximate was in part contemporaneous with Rome Trough subsidence and part of though the basement complex is assumed to be a “no-migration” sealing location of cross-section. Conasauga Group deposition. Th e Rome Trough High was a linear topo- interval, the sequestration and hydrocarbon potential of the basement graphic Precambrian feature that developed as a northwestern shoulder complex is also poorly understood. Anomalous lithologies, reported hy- of the Rome Trough, eff ectively controlling Mt. Simon and Conasauga drocarbon shows, zones of lost circulation, electric log patterns, and abun- Group deposition. dant layered seismic refl ectors suggest potential reservoir development. Modernizing of available rock and geophysical data and collecting new • Following Mt. Simon deposition, the Eau Claire Formation, the upper data will lead to new models for the basement complex and the overly- portion of Conasauga Group and equivalents formed the stable very low ing Paleozoic units. relief Ohio Platform, which was dominated by cyclical mixed clastic-car- bonate sediments throughout central Ohio and primarily carbonates east- • Although Mt. Simon industrial waste injection data suggests higher po- ward. Well developed potential saline reservoirs exist within the Sandusky tential than the underlying basement complex, available rock and geo- Formation and also require detailed testing and further evaluation. physical data should be updated and modernized to increase our under- standing of heterogeneity and lateral facies changes controlling the extent • Th e new term Sandusky Formation is proposed to eliminate and clarify and performance of saline reservoirs. current sub-Knox correlation problems.
FUTURE WORK
• Following detailed modern analyses of available deep well cores, sample • Updated mapping and testing of new models will increase our understand- cuttings, and electric logs, a viable exploration program to drill and test ing of the extent and quality of potential Cambrian saline reservoirs. new geologic models for the Ohio region should begin. Seismic refl ection data (i. e., Fayette Co., Ohio) should be combined with geopotential data • Th is future work has signifi cant implications for hydrocarbon explora- and subsurface mapping to select drill sites with high potential for saline tion, gas storage, hazardous and nonhazardous waste injection, and CO2 reservoirs and to evaluate new geologic models. sequestration, thus for the economic future of the Ohio region as well.
REFERENCES CITED
Blakely, R. C., 2006, Northern Arizona University
Partial electric log showing density cutoffs and relative porosity sidence of the Ohio Platform for (RHOB in gm/cc: 2.68 ~0%, 2.55 ~8%, 2.40 ~16%) for Conasauga/ rocks in the central Appalachian basin from Fayette County, Ohio, to Botetourt County, Virginia: U.S. Geo- Platform during Middle Cambrian time Sandusky. Gamma ray, neutron, and PE curves shown where the post Mt. Simon refl ectors, available. Density cutoffs are not corrected for complex lithology. logical Survey Miscellaneous Investigations Series Map I-2495. and were completely buried prior to Cona- skypic.com, 2003,