Tectonic tilting of the northern Owens Valley, California
- Univ. of California, Santa Barbara, CA (United States). Dept. of Geological Sciences
Tectonic rotation is characteristic of active deformation in many of the structural basins of the Basin and Range. The Owens Valley (OV) is the most western basin of the province. The structure, stratigraphy, and geomorphology of the northern OV suggest that there has been active eastward tilting of the valley throughout at least the late Quaternary. A series of analytical techniques are developed here which quantify the age, rate, and character of deformation. The geomorphic clock'' of the northern OV was reset 738,000 years ago by the unroofing of Long Valley Caldera, just to the north, and the emplacement of the Bishop Tuff ignimbrite sheet. Since that time, cooling joints in the tuff and channels cut into the surface of the sheet have been reoriented, and fluvial terraces and alluvial fans have been tilted. Each of these analyses have the same solution--a net down-to-the-east rotation of the valley block at a mean rate of 0.8--1.0[degree]/Ma. Other indicators of tilt support this solution: fluvial and lacustrine strata at the type-locality of the Glass Mountain ashes dip approximately 1[degree] to the east; and gravity measurements of basement geometry demonstrate a dip of 11.0--13.7[degree] eastward. Extrapolating a uniform rate of tilt, the dip of the basement suggest that sedimentation in the OV began in the late Miocene. The character of deformation across the study area is consistent with motion on the Coyote warp anticlinal trend, near the base of the Sierra Nevada. The author propose that the Coyote warp has acted as a tectonic hinge, accommodating westward rotation of the Sierra Nevada and eastward rotation of the northern OV.
- OSTI ID:
- 5936801
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALIFORNIA
VALLEYS
TECTONICS
AGE ESTIMATION
CALDERAS
DEFORMATION
GEOLOGIC MODELS
GEOMORPHOLOGY
LONG VALLEY
QUATERNARY PERIOD
ROTATION
SEDIMENTARY BASINS
SEDIMENTATION
STRATIGRAPHY
TUFF
CENOZOIC ERA
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
MOTION
NORTH AMERICA
USA
580000* - Geosciences