sentences:  Dockum Group
  
  The Dockum is a Late Triassic (approximately late Carnian through Rhaetian, or 223–200 Ma) geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle.The Dockum reaches a maximum thickness of slightly over 650 m but is usually much thinner.