Analytic and petrologic studies of both detrital and chemical components of the Pennsylvanian Excello Shale Member of the Senora Formation in northeastern Oklahoma divide the shale member into a northern carboniferous facies and a southern bituminous facies. The change occurs just south of a limestone reef in the underlying Breezy Hill Limestone Member. Continued study and shale-facies mapping will aid in determining the subsurface position of the reef and the distribution of environments of shale deposition. In shales, clay mineralogy is only a general indicator of environment. Other components such as iron, phosphate, carbonate, organic matter, zeolites, and trace elements are more sensitive to environmental change.

You do not currently have access to this article.