Sequence stratigraphy and depositional systems of the Mansfield Sand, upper Atoka Formation, Arkoma Basin, Arkansas.

摘要

The Mansfield sand is an informally named member of the Pennsylvanian Atoka Formation in Arkansas. Once a productive gas reservoir, the Mansfield is situated in a double plunging anticline in the southern portion of the Arkoma Basin. The formation is internally composed of sandstone units ranging in thickness from tens of feet to over a hundred feet interbedded with shale units ranging in thickness from several tens of feet to hundreds of feet. Previous studies have focused on the stratigraphy of the lower and middle Atoka.;A detailed subsurface study of the stratigraphic framework of the Mansfield sand was conducted using conventional lithostratigraphy and sequence stratigraphy. Four progradational parasequences have been identified within a highstand systems tract. Deposition of the Mansfield occurred in a deltaic environment on a sandy, fluvial or wave dominated shoreline.