Stratigraphy of the Palo Pinto Formation in northeastern Palo Pinto County, Texas.

摘要

Several outcrops of Late Pennsylvanian (Early Missourian) age are exposed in northeastern Palo Pinto County. Early workers, Moore and Plummer (1921), designated reference and type sections for the Palo Pinto Formation in this area. However, their work remains unclear in regards to location and in defining subjacent and superjacent unit boundaries. Later work by Plummer and Hornberger (1935), Cheney (1940) and others have further confused the terminology used to define both formational and group boundaries. Lateral facies variations within rocks of the Palo Pinto Formation make correlation of this unit a difficult and tenuous task. Because the Palo Pinto Formation begins the Canyon Group and represents a change from siliclastic dominated to carbonate dominated deposition, determination of this boundary is critical in defining where in the stratigraphic section this major shift took place.; A regionally extensive and correlatable bed, herein referred to as the Union Hill Member of the Palo Pinto Formation, is observed at the outcrop level through careful observation. This bed is used to define the base of the Palo Pinto Formation and hence, the base of the Canyon Group. (Abstract shortened by UMI.)