The Vertebrate Fauna and Geologic Age of Trinity River Terraces in Henderson County, Texas

Abstract

An attempt is made to correlate the various stratigraphic units of the Pleistocene in Henderson and adjoining counties to related up-dip terrace deposits with the equivalent formations of the Gulf Coastal Plain and to determine the age of these terraces as compared with the glacial deposits in the glaciated states. The highest of a series of 3 alluvial terraces associated with the present Trinity River in the area under consideration in east-central Texas is especially well-developed and offers the possibility of serving as a standard unit for correlation of other stream deposits in the Texas coastal plain. The 3 terraces are herein designated, from highest to lowest, as Trinity Terrace, Trinidad Terrace, and Power Plant Terrace. An interesting assemblage of vertebrate fossils containing 17 genera, including a new species of Megalonyx, collected from numerous sand and gravel pits located on the highest terrace, is described. On the basis of paleontologic and stratigraphic evidence it is concluded that all 3 of the terrace deposits were laid down during the Wisconsin stage of the Pleistocene. It is suggested that Trinity Terrace is the up-stream equivalent of the Lissie formation; that the Trinidad Terrace may be equivalent to the Beaumont formation; and that the present flood plain represents practically all of the Recent time.