BUREAU OF ECONOMIC GEOLOGY The University of Texas at Austin Peter T. Flawn, Director Guidebook 8 The Geologic Story of Palo Duro Canyon By William H. Matthews III [Illustration: THE UNIVERSITY OF TEXAS AT AUSTIN] August 1969 Second Printing August 1983 Contents Introduction 1 Acknowledgments 2 Park history 3 Ancient man in Palo Duro Canyon 3 Indians of the Plains 3 Advent of the White Man 3 Regional setting 8 The geologic story 10 The canyon’s rocks and minerals 10 Unraveling earth history 10 The geologic column and geologic time scale 12 Geologic formations exposed in Palo Duro Canyon 16 Quartermaster Formation 17 Tecovas Formation 19 Trujillo Formation 22 Ogallala Formation 23 Rocks of the Pleistocene 28 How the canyon was carved 29 The geologic work of running water 29 Weathering and gravity add the final touch 30 Weathering 30 Mass-wasting 31 Differential erosion 31 What to do and see at Palo Duro Canyon State Park 33 Park Entrance 33 Coronado Lodge and Observation Point 33 The Scenic Drive 33 Pioneer Amphitheatre 33 Sad Monkey Train Ride 35 Triassic Peak 35 Spanish Skirts 37 Catarina Cave 37 Santana’s Face 37