Part I: Onshore Wilcox

摘要

The Wilcox Group is mostly Paleocene but also contains Eocene strata in its upper portion (Xue and Galloway, 1993). It transitionally overlies the Midway Shale and is overlain by the Eocene Claiborne Group and the Queen City and Yegua formations. The Wilcox Group is a thick sequence of predominantly clastic rocks that was deposited during the first of a series of pulses of Cenozoic sedimentation into the Gulf of Mexico Basin. Lower Wilcox strata prograded over distal, fine-grained marine clastics of the underlying Midway Group. Thick, progradational shoreline and shelf-margin sequences characterize the Lower and Upper Wilcox intervals, while the Middle Wilcox is a predominantly transgressive to slightly aggradational succession. The uppermost Wilcox is capped sub-regionally by thick, amalgamated, predominantly fluvial strata of the Carrizo Sandstone. It is separated from the overlying Reklaw Formation ofrnthe Claiborne Group by a regionally extensive marine flooding surface (Xue, 1997).