Geo-pic of the week: Sand and clay of the Wilcox Group

This rather handsome outcrop of the Wilcox group consists of alternating layers of sand and clay of the Eocene Epoch which lasted from about 56-34 million years ago.   The Wilcox Group is a non-marine unit mostly composed of sand with lesser clay, silt, gravel, and lignite (low-grade coal).  

This geologic unit is part of a larger sequence of loosely-consolidated sedimentary rocks exposed in south central Arkansas, south of Pulaski county.  These rocks are the northern extent of the West Gulf Coastal Plain, a physiographic province that stretches from central Arkansas, south, to the Gulf of Mexico.