Stratigraphy and provenance of shallow sandstones encountered in wells in townships 9 & 10 North, Ranges 6 & 7 West, White County, Arkansas.

摘要

Paleozoic formations in western Arkansas have been well-studied; however, they are not well-understood in the eastern part of the state. The study area encompasses Townships 9. N. and 10. N., Ranges 6. W. and 7. W. in north-central White County, Arkansas. This area is at the intersection of four physiographic provinces as defined by the Arkansas Geologic Survey---the Ozark Plateaus, the Arkansas River Valley, the Ouachita Mountains, and the Mississippi Alluvial Plain. Interpretations of the surface unit in the area disagree. The Arkansas Geologic Map shows that the Morrowan Hale Formation crops out in the area; however, various petroleum geologists suggest that the surface unit in the area is of the Atoka Formation. Several wells in the area have produced natural gas from the sandstones in question, meriting further investigation of the units' potential source.;Petrographic analysis of 17 thin sections prepared from sidewall cores taken from three wells in the study area, correlation of 141 wireline logs, and construction of cross sections, gross sand isopachs, and structure maps were used to develop a stratigraphic framework of the area. These analyses imply that the subject units are likely of the Hale Formation and have multiple sources including the Ouachita Mountains, the Appalachian Mountains, the Ozark Dome, and the North American cratonic interior. Additionally, the sandstones were likely deposited in a transitional near-shore marine environment with a fluvial-deltaic influence.