Phanerozoic Tectonics of the Basin and Range - Colorado Plateau Transition from COCORP Data and Geologic Data: A Review
- Muawia Barazangi and
- Larry Brown
Published Online: 15 MAR 2013
Copyright 1986 by the American Geophysical Union.
Reflection Seismology: The Continental Crust
How to Cite
Allmendinger, R. W., Farmer, H., Hauser, E., Sharp, J., Von Tish, D., Oliver, J. and Kaufman, S. (1986) Phanerozoic Tectonics of the Basin and Range - Colorado Plateau Transition from COCORP Data and Geologic Data: A Review, in Reflection Seismology: The Continental Crust (eds M. Barazangi and L. Brown), American Geophysical Union, Washington, D. C.. doi: 10.1029/GD014p0257
- Published Online: 15 MAR 2013
- Published Print: 1 JAN 1986
Print ISBN: 9780875905143
Online ISBN: 9781118670118
- Seismic reflection method—Congresses
The COCORP 40°n transect in Utah and easternmost Nevada crosses the eastern Basin and Range Province and the northwest Colorado Plateau. This part of the Cordillera of western North America has been the site of late Precambrian rifting, Mesozoic and early Cenozoic thrust faulting, and middle and late Cenozoic extension. The COCORP data, in combination with drilling and surface geologic data, suggest that a major change in seismic character and crustal structure occurs at the location of the autochthonous hingeline, which was formed during the Precambrian rifting and subsequent passive margin stage. East of the hingeline, there is little evidence that neither thrust faults nor low-angle normal faults cut deeply into the continental basement. West of the hingeline, a prominent, west-dipping seismic fabric may correspond to Cenozoic and perhaps Mesozoic low-angle structures that cut down to middle and lower crustal levels. The deepest reflections in the Basin and Range (28–30 km) correspond in depth to a prominent mid-crustal horizon (−27 km) in the Colorado Plateau; their relation is uncertain. The Colorado Plateau crust appears to be more than 15 km thicker than the Basin and Range crust. Also, the Colorado Plateau data is dominated by diffractions, where as the Basin and Range has a more persistent west-dipping or layered fabric. These contrasting seismic characters may be typical of cratonic versus orogenic crust, respectively.