Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs, and Possible Glaciation in Selected Areas of Arizona, California, and Nevada

This guidebook, prepared in conjunction with the 2008 joint meeting of the GSA Cordilleran and Rocky Mountain Sections, contains background information and road logs for eleven field trips in Nevada, Arizona, and California. Southern Nevada and adjoining areas contain a rich geologic history spanning the interval from the Paleoproterozoic to the present. Las Vegas lies at or near several critical geological junctures and localities including the structural boundary between the Colorado Plateau and Basin and Range, the physiographic boundary between the Great Basin and the southern Basin and Range, the eastern margin of the Sevier fold-and-thrust belt, the tectonically active Death Valley area, tilted and faulted volcanic-plutonic systems exposing the upper part of the crust, and the enigmatic “amagmatic zone.” With guides in this volume spanning the geologic record from the Ediacaran (late Neoproterozoic) to the Holocene, covering ground from the middle crust to the surface, and looking at topics from tectonics to paleontology, volcanism to glaciation, this volume offers something for everyone.
Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River
-
Published:January 01, 2008
-
CiteCitation
James E. Faulds, Keith A. Howard, Ernest M. Duebendorfer, 2008. "Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River", Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs, and Possible Glaciation in Selected Areas of Arizona, California, and Nevada, Ernest M. Duebendorfer, Eugene I. Smith
Download citation file:
- Share
Abstract
In northwest Arizona, the relatively unextended Colorado Plateau gives way abruptly to the highly extended Colorado River extensional corridor within the Basin and Range province along a system of major west-dipping normal faults, including the Grand Wash fault zone and South Virgin–White Hills detachment fault. Large growth-fault basins developed in the hanging walls of these faults. Lowering of base level in the corridor facilitated development of the Colorado River and Grand Canyon. This trip explores stratigraphic constraints on the timing of deformation and paleogeographic evolution of the region. Highlights include growth-fault relations that constrain the timing of structural demarcation between the Colorado Plateau and Basin and Range, major fault zones, synextensional megabreccia deposits, nonmarine carbonate and halite deposits that immediately predate arrival of the Colorado River, and a basalt flow interbedded with Colorado River sediments.
Structural and stratigraphic relations indicate that the current physiography of the Colorado Plateau–Basin and Range boundary in northwest Arizona began developing ca. 16 Ma, was essentially established by 13 Ma, and has changed little since ca. 8 Ma. The antiquity and abruptness of this boundary, as well as the stratigraphic record, suggest significant headward erosion into the high-standing plateau in middle Miocene time. Thick late Miocene evaporite and lacustrine deposits indicate that a long period of internal drainage followed the onset of extension. The widespread distribution of such deposits may signify, however, a large influx of surface waters and/or groundwater from the Colorado Plateau possibly from a precursor to the Colorado River. Stratigraphic relations bracket arrival of a through-flowing Colorado River between 5.6 and 4.4 Ma.
- Arizona
- Basin and Range Province
- basins
- breccia
- Cenozoic
- chemically precipitated rocks
- chlorides
- Colorado Plateau
- Colorado River
- depositional environment
- detachment faults
- evaporites
- extension
- faults
- field trips
- growth faults
- guidebook
- halides
- halite
- lacustrine environment
- lithostratigraphy
- megabreccia
- Mohave County Arizona
- normal faults
- North America
- outcrops
- paleogeography
- paleohydrology
- road log
- sedimentary basins
- sedimentary rocks
- syntectonic processes
- transition zones
- United States
- northwestern Arizona