En echelon Miocene rifting in the southwestern United States and model for vertical-axis rotation in continental extension
Journal Article
·
· Geology; (United States)
- Univ. of Utah, Salt Lake City (United States)
- Univ. of North Carolina, Chapel Hill (United States)
Two areas of intense early Miocene crustal extension in the southwestern United States, the Colorado River trough and the central Mojave Desert, are separated by a weakly deformed area in the eastern Mojave Desert. The authors propose that these areas form a left-stepping en echelon rift system linked by a ductile detachment at depth. The en echelon geometry explains the southward loss of displacement in the central Mojave Desert and northward loss of coeval displacement in the Colorado River trough, and it incorporates seismic reflection evidence that mid-crustal Tertiary extensional mylonites continue beneath the weakly deformed area. This geometry also explains clockwise paleomagnetic declination anomalies from lower Miocene rocks as recording thin-skinned, detached rotations; large-scale block rotations are not required. Obliquity of the northeast-trending crustal-extension vector to the east-west-trending early Miocene synextensional volcanic belt may have caused the en echelon pattern to develop.
- OSTI ID:
- 7201985
- Journal Information:
- Geology; (United States), Journal Name: Geology; (United States) Vol. 19:12; ISSN GLGYB; ISSN 0091-7613
- Country of Publication:
- United States
- Language:
- English
Similar Records
Paleomagnetic reversals in Miocene dikes, and tectonic evolution of the Crossman block, Mohave Mountains, Arizona
Three extensional basin types associated with detachment-style faulting, early Miocene of the central Mojave Desert
Paleomagnetism of middle Miocene volcanic rocks in the Mojave-Sonora desert region of western Arizona and southeastern California
Conference
·
Wed Mar 31 23:00:00 EST 1993
· Geological Society of America, Abstracts with Programs; (United States)
·
OSTI ID:5022330
Three extensional basin types associated with detachment-style faulting, early Miocene of the central Mojave Desert
Conference
·
Wed Mar 31 23:00:00 EST 1993
· Geological Society of America, Abstracts with Programs; (United States)
·
OSTI ID:5420051
Paleomagnetism of middle Miocene volcanic rocks in the Mojave-Sonora desert region of western Arizona and southeastern California
Journal Article
·
Tue Jan 09 23:00:00 EST 1990
· Journal of Geophysical Research; (United States)
·
OSTI ID:5010223
Related Subjects
58 GEOSCIENCES
580000* -- Geosciences
ARIZONA
BASEMENT ROCK
CALIFORNIA
CENOZOIC ERA
DEVELOPED COUNTRIES
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOMETRY
IGNEOUS ROCKS
INCLINATION
MAGNETISM
MAPPING
MATHEMATICS
METAMORPHIC ROCKS
MIOCENE EPOCH
NORTH AMERICA
PALEOMAGNETISM
PETROGENESIS
RIFT ZONES
ROCKS
TERTIARY PERIOD
USA
VOLCANIC ROCKS
580000* -- Geosciences
ARIZONA
BASEMENT ROCK
CALIFORNIA
CENOZOIC ERA
DEVELOPED COUNTRIES
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOMETRY
IGNEOUS ROCKS
INCLINATION
MAGNETISM
MAPPING
MATHEMATICS
METAMORPHIC ROCKS
MIOCENE EPOCH
NORTH AMERICA
PALEOMAGNETISM
PETROGENESIS
RIFT ZONES
ROCKS
TERTIARY PERIOD
USA
VOLCANIC ROCKS