See more from this Division: Topical Sessions
See more from this Session: Coastal Tectonics of the Pacific Rim: Geomorphology, Structure, and Hazards
Abstract:
Ongoing field-based studies and satellite imagery analysis reveal that the Cerro Prieto area exhibits mud pots, mud volcanoes, fumaroles, geysers, thermal springs, load casts, mud dykes, sand blow structures, minor fault scarps, terraces, benches, deflected streams, and episodes of cutting and filling occurred in the drainage. The observed surficial deposits derived from adjoining desert ranges but mostly from the Colorado River show a distribution influenced by the Cerro Prieto fault and several subsidiary oblique and/or orthogonal trending faults. These faults are all active and form a pull-apart network style that is correlative with a regional thermal anomaly and frequent seismic activity, usually accompanied by subsidence (although subsidence occurs aseismically as well).
The youngest stratigraphic record in this arid landscape contains evidence of several unconformities and a large-scale southeastward shift of the Colorado River in order to reach the Gulf of California. The shifting of the Colorado River is clearly suggestive of a syn-tectonic deposition and attests a genetic relationship to the Cerro Prieto Fault that controls the deformation of the Cerro Prieto area.
The geomorphological and sedimentological features are the result of tectonic subsidence, natural thermal fluid activity, earthquake activity and fault movements in a hazardous scenery during late quaternary times.
See more from this Division: Topical Sessions
See more from this Session: Coastal Tectonics of the Pacific Rim: Geomorphology, Structure, and Hazards