GEOLOGY OF PALO DURO CANYON
H. Charles Hood
Barbee Exploration Inc.
Amarillo, Texas
Introduction
Palo Duro Canyon begins in the northeastern part of Randall County, Texas, and continues on a southeasterly course through Armstrong and Briscoe counties. Responsible for cutting this winding 700-foot gorge is the Prairie Dog Town Fork of the Red River. Several major tributaries have furnished help in the canyon-making process, creating beautiful side canyons, usually of somewhat lesser size.
Palo Duro Canyon forms a re-entrant into the eastern High Plains “Caprock” Escarpment. This escarpment runs in a north-south direction for several hundred miles, and forms the natural boundary between the Southern High Plains or Llano Estacado to the west, and the Low Rolling Plains or Osage Plains to the east.
Rocks representing a time span of some 240 million years are found exposed in the canyon walls. The Upper Permian Quartermaster Formation is the oldest rock formation found in Palo Duro Canyon. The Quartermaster is overlaid by the Upper Triassic Tecovas and Trujillo formations (Dockum Group), which form the bulk of the rocks exposed and are responsible for many of the spectacular rock shapes seen in the canyon. Capping the rock record and forming the steep rim around the upper reaches of the canyon is the late Tertiary Ogallala Formation. Much of the water used for cities and irrigation purposes on the High Plains comes from the Ogallala aquifer. An assortment of eolian “cover sands” and playa lake deposits dot the present High Plains surface we see today. The major rock units dip gently south and east, as does the erosional High Plains surface.