Abandonment of Unaweep Canyon (1.4–0.8 Ma), Western Colorado: Effects of Stream Capture and Anomalously Rapid Pleistocene River Incision
CRevolution 2: Origin and Evolution of the Colorado River System II themed issue Abandonment of Unaweep Canyon (1.4–0.8 Ma), western Colorado: Effects of stream capture and anomalously rapid Pleistocene river incision Andres Aslan1,*, William C. Hood2,*, Karl E. Karlstrom3,*, Eric Kirby4, Darryl E. Granger5,*, Shari Kelley6, Ryan Crow3,*, Magdalena S. Donahue3,*, Victor Polyak3,*, and Yemane Asmerom3,* 1Department of Physical and Environmental Sciences, Colorado Mesa University, Grand Junction, Colorado 81501, USA 2Grand Junction Geological Society, 515 Dove Court, Grand Junction, Colorado 81501, USA 3Department of Earth and Planetary Sciences, University of New Mexico, Northrop Hall 141, Albuquerque, New Mexico 87131, USA 4College of Earth, Ocean and Atmospheric Sciences, Oregon State University, 202D Wilkinson Hall, Corvallis, Oregon 97330, USA 5Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA 6New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, New Mexico 87801, USA ABSTRACT opment of signifi cant relief between adjacent through resistant Precambrian bedrock (Fig. 2). stream segments, which led to stream piracy. It has no major river at its base, and is currently Cosmogenic-burial and U-series dating, The response of rivers to the abandonment drained by two underfi t streams, East and West identifi cation of fl uvial terraces and lacus- of Unaweep Canyon illustrates how the Creeks, which drain the northeast and southwest trine deposits, and river profi le reconstruc- mode and tempo of long-term fl uvial incision ends of the canyon, respectively. Starting with tions show that capture of the Gunnison are punctuated by short-term geomorphic the Hayden Survey (Peale, 1877), geologists River by the Colorado River and abandon- events such as stream piracy.
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