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Selected geochemistry and mineralogy of Paleozoic strata in northern and central Appalachian basin, U.S.A., 1994-2012


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Enomoto, C.B., Dulong, F.T., and Milici, R.C., 2017, Selected geochemistry and mineralogy of Paleozoic strata in northern and central Appalachian basin, U.S.A., 1994-2012: U.S. Geological Survey data release,


A U.S. Geological Survey (USGS) provisional geochemical and mineralogical database for hydrocarbon-rich shale in the Appalachian region has been compiled by Catherine Enomoto, Frank Dulong and Robert Milici for online distribution. USGS staff collaborated with geologists in State geological agencies to obtain samples that were analyzed for organic properties, including Rock Eval analyses, total organic carbon (TOC), thermal maturity, and semi-quantitative mineralogy. However, the database also contains previously published data, with appropriate citations included. Previously unpublished data are from samples collected and analyzed between 2007 and 2012 from wells drilled between 1931 and 2009, and from exposures in the northern and [...]


Point of Contact :
Catherine Enomoto
Originator :
Enomoto, Catherine B., Dulong, Frank T., Milici, Robert C.
Metadata Contact :
Eric A Morrissey
Publisher :
U.S. Geological Survey
Distributor :
U.S. Geological Survey - ScienceBase
USGS Mission Area :
Energy and Minerals
SDC Data Owner :
Energy Resources Program

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Selected_geochemistry_and_mineralogy_of_Paleozoic_strata_in_the_Appalachian_basin_USA_1994-2012.xlsx 242.4 KB application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Selected_geochemistry_and_mineralogy_of_Paleozoic_strata_in_the_Appalachian_basin_USA_1994-2012.html 325.83 KB text/html
Selected_geochemistry_and_mineralogy_of_Paleozoic_strata_in_the_Appalachian_basin_USA_1994-2012.csv 369.57 KB text/csv


Organic richness and thermal maturity data for source rocks help predict the amount of oil and/or gas that may be generated and provide the fundamental information for resource evaluation. Various indicators are used to assess the thermal maturity of source rocks; Tmax is one of the prime Rock-Eval measurements used for determination of thermal maturity. Certain parameters, such as the Hydrogen Index (HI) and the Production Index (PI), are derived from the Rock-Eval pyrolysis measurements and also provide a general indication of the source rock maturity. Other evaluation methods for assessing thermal maturity include vitrinite reflectance (%Ro), the thermal alteration index (TAI), and conodont alteration index (CAI). In general, measured Ro reported as “indigenous” or as “edited population groups,” together with the number of measurements per sample, can be considered the most reliable representation of thermal maturation. Calculated Ro values are considered to be approximations, and Ro values corrected for suppression utilize the methodology of Lo (1993) to correct for anomalously low values of vitrinite reflectance. Semi-quantitative mineralogy data may help determine the depositional environment, thermal maturity, and fracability of these formations.

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Type Scheme Key
DOI doi:10.5066/F7KW5DZ8

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