Ichnology and Mineralogy of the Main Glauconite Bed, Claiborne Group, Middle Eocene, Texas: Paleoenvironmental Implications

Sherie Harding and A. Ekdale
[email protected]

A trace fossiliferous greensand crops out on the south bank of the Brazos River on the Texas Gulf Coastal Plain. It is the 'Main Glauconite bed' (MGB) of the Stone City Member, Crockett Formation, Claiborne Group, Middle Eocene, a prominent 1.7 m thick green bed. The MGB and the associated stratigraphic section have been studied extensively by paleontologists and stratigraphers for many years, so the general paleoenvironmental setting is understood. This present study combines ichnology and mineralogy to provide an innovative approach and new insight into the biological and sedimentary processes that occurred during accumulation of the MGB. Characterization of the composite ichnofabric, implications of the pelleted sedimentary fraction, ichnologic nature of the bed boundaries, and the clay mineralogy all come together to provide an integrated approach to understanding this complex depositional environment.

AAPG Search and Discovery Article #90167©2013 GCAGS and GCSSEPM 63^rd Annual Convention, New Orleans, Louisiana, October 6-8, 2013