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U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 00-496

Thermal Maturity Patterns (CAI and %Ro) in the Ordovician and Devonian Rocks of the Appalachian Basin in New York State

By David J. Weary, 1 Robert T. Ryder, 1 and Richard Nyahay2

Online Version 1.0


Abstract

The objective of this study is to enhance existing thermal maturity maps in New York State by establishing: 1) new subsurface CAI data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. The thermal maturity of the Ordovician and Devonian rocks is of major interest because they contain the source for most of the unconventional natural gas resources in the basin. Thermal maturity patterns of the Middle Ordovician Trenton Group are evaluated here because they closely approximate those of the overlying Ordovician Utica Shale that is believed to be the source rock for the regional oil and gas accumulation in Lower Silurian sandstones (Jenden and others, 1993; Ryder and others, 1998). Improved CAI-based thermal maturity maps of the Ordovician are important to identify areas of optimum gas generation from the Utica Shale and to provide constraints for interpreting the origin of oil and gas in the Lower Silurian regional accumulation, in particular, its basin-centered part (Ryder, 1998). Thermal maturity maps of the Devonian will better constrain burial history-petroleum generation models of the Utica Shale, as well as place limitations on the origin of regional oil and gas accumulation in Upper Devonian sandstone and Middle to Upper Devonian black shale.

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PDF File of the Report

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The compressed arcview.zip volume (360 KB) contains ArcView data as shapefiles in the arcview_data/ny_cai_files subdirectory, the metadata file (ny_metadata.txt), and an Arcview project file (NY_THERM.APR), which will display the data. All themes are projected to stateplane projection, NAD27 datum. The point and line data are basically a georeferenced subset of that in the tables and figures of the paper. A description of the data is listed in the ENTITY_AND_ATTRIBUTE_INFORMATION section of the metadata.

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1U.S. Geological Survey. 2New York State Geological Survey, Albany, NY 12230.

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U.S. Department of the Interior, U.S. Geological Survey
This page is https://pubs.usgs.gov/openfile/of00-496/
Maintained by: Eastern Publications Group
Contact: David Weary
Last Modified 02.22.01