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Unconventional Shale Resources

Since the early 2000s, new technologies have been applied to the production of oil and natural gas. Horizontal drilling into organic-rich black shales is a key process combined with these new technologies that has opened up opportunities for oil and natural gas production. Previously, reservoir rocks that lie above source rocks were targets for oil and natural gas exploration. Oil and gas naturally migrate from the source rocks into these more permeable “conventional reservoir” rocks, which are then drilled to produce those hydrocarbons. The current paradigm is to drill directly into the source rocks (also known as unconventional reservoirs), such as a black shale, then hydraulically fracture the shales to produce larger-scale permeability, and thus allow oil, natural gas, and natural gas liquids to flow into the horizontal well bore. This technology is currently being used in the exploration and production of hydrocarbons from the Ordovician-age Utica Shale/Point Pleasant Formation of Ohio.

Resource estimates indicate the Devonian-age Marcellus Shale is the largest exploration play in the eastern United States. Because the Marcellus Shale thins rapidly westward into Ohio, there are significantly fewer wells drilled into the Marcellus than in the Utica/Point Pleasant. Because of the favorable geology in Ohio, the Point Pleasant Formation is currently Ohio’s most significant producer of oil, natural gas, and natural gas liquids.

In response to demand for data on these shales, the Division of Geological Survey has compiled a series of documents and data sets for both rock units, along with reports on other organic-rich shales such as the Ohio Shale. Published diagrams, isopach (thickness) maps, cross sections, and location maps for Marcellus and Utica/Point Pleasant producing wells are among the numerous documents and links provided on this page, which is updated periodically as new information and data becomes available.

Additional Resources

Unconventional Shale Resources Reports

Organic-thickness map of the Marcellus Shale in the Appalachian Basin

Organic-thickness map of the Marcellus Shale in Ohio

Stratigraphic cross sections of the Devonian Shale interval, eastern Ohio and west-central West Virginia:

  • Northwest–southeast, along dip
  • Southwest–northeast, along strike

ODNR Division of Geological Survey Digital Data File 6: The Ohio Compilation of Devonian Shale Data and Investigations (2007)

ODNR Division of Geological Survey Open File Report 88-2: Analysis of Stratigraphic and Production Relationships of Devonian-Shale Gas Reservoirs in Lawrence County, Ohio (1988)

ODNR Division of Geological Survey Open File Report 88-3: Analysis of Stratigraphic and Production Relationships of Devonian Shale Gas Reservoirs in Meigs County, Ohio (2013)

ODNR Division of Geological Survey Open File Report 2016-3: Mapping Source Rock and Thermal Maturity of the Devonian Shale Interval in Eastern Ohio (2016)

ODNR Division of Geological Survey Geologic Note 13: High-Resolution Stratigraphy and Subsurface Mapping of the Lower Part of the Huron Member of the Ohio Shale in Central and Eastern Ohio Allow for Detailed Snapshots of Basin Development (2018)

GIS and Database Resources

Oil & Gas Well Locations

Oil & Gas Fields of Ohio

Wells reaching the base of the Cambrian Knox Dolomite in Ohio

Precambrian Structure Contours and Faults in Ohio 

Core Locations

Underground Sources of Drinking Water (USDW)

Wells used to map the Trenton Limestone in northwestern Ohio

Wells that reach the top of the Knox Unconformity in Ohio

Miscellaneous support files for geologic records at the ODNR Division of Geological Survey

Geophysical Log Index Files

TIF file index

LAS file index

Other Publications

Search for Division of Geological Survey reports and maps in our Publications Catalog. Or use the links below to search for publications held by one of our partners. 

OSU Knowledge Bank

State Library of Ohio (Ohio Memory)