Pleistocene geology of Red River Basin in Texas

The Red River rises in northeastern New Mexico and extends across northern Texas and east of the Panhandle serves as the northern border of that State. The late Cenozoic geology of the Red River basin has been studied intensively in northwestern Texas and in Louisiana. This report summarizes the results of our studies of the late Cenozoic geology of the Red River basin in Texas. Late Tertiary terrace deposits have been identified as far east as Montague County and deposits of Nebraskan age have been recognized somewhat farther east. Terrace deposits of late Kansan and early Wisconsinan age have been traced essentially throughout the basin in Texas. In north-central and northeastern Texas the names Hardeman, Ambrose, and Cooke are proposed for the alluvial terraces that were formed during late Kansan and early and late Wisconsinan time. In northeastern Texas we found pimple mounds occurring on all terrace surfaces older than Wisconsinan. Varied and diagnostic faunas of fossil mollusks are reported from Kansan, early Wisconsinan, and late Wisconsinan deposits throughout most of the basin in northern Texas, and Pearlette volcanic ash occurs locally in the deposits of Kansan age. The Pleistocene history of the Red River has been a succession of alternating episodes of valley deepening, accompanied by progressive headward encroachment of nickpoints in northwestern Texas, and less extensive valley alluviation.