Pre-transform early Miocene extension in western California

Tennyson, Marilyn E.

doi:10.1130/0091-7613(1989)017<0792:ptemei>2.3.co;2

Cited by 33 publications

(31 citation statements)

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“…Restoration of this slip (plus ~30 km on the parallel Canton fault; Figs. 16B, 16C) brings Precambrian and Mesozoic crystalline rocks, uppermost Cretaceous-Paleogene deep-marine strata, the Plush Ranch Formation, and high-and low-angle faults into alignment with those of the Soledad and Orocopia areas, as discussed above and by Crowell (1975a), Bohannon (1975Bohannon ( , 1976, Tennyson (1989), Hendrix et al (2010) and Hoyt (2012) (Figs. 16C, 17).…”

Section: Reversal Of Vertical-axis Rotation and San Gabriel Fault Offsetmentioning

confidence: 82%

“…16, 17). These NE-SW trends parallel both low-angle and high-angle faults of the Soledad and Plush Ranch basin areas (including the Fenner fault in the Devil's Punchbowl area), following appropriate removal of variable clockwise rotation of these blocks (e.g., Bohannon, 1975Bohannon, , 1976Tennyson, 1989;Hendrix et al, 2010;Hoyt, 2012). …”

Section: Reversal Of Regional Extensionmentioning

confidence: 99%

“…As Crowell (1975a) pointed out, this reconstruction also brings into proximity: (1) similar diverse Precambrian and Mesozoic crystalline rocks; (2) the uppermost Cretaceous-Paleogene deepmarine San Francisquito Formation (Kooser, 1982) north of Sierra Pelona with the Eocene Maniobra Formation; (3) the Vasquez and Diligencia formations of overlapping ages, similar interbedded volcanic units and similar basin styles; and (4) both low-angle and high-angle faults of similar character. Bohannon (1975Bohannon ( , 1976, Tennyson (1989) and Hendrix et al (2010) refi ned this reconstruction and proposed more specifi c correlations (utilized in Fig. 17).…”

Section: Reversal Of San Andreas Fault Offsetmentioning

confidence: 99%

“…NW-SE-directed extension characterized part of the southwestern California continental margin from around 26-18 Ma (Bohannon, 1975(Bohannon, , 1976Hendrix and Ingersoll, 1987;Tennyson, 1989;Hendrix et al, 2010); this extension preceded and partially coincided with NE-SW extension in the Mojave Desert and Colorado River area (Glazner and Bartley, 1984;Wust, 1986;Sherrod and Tosdal, 1991;Ingersoll et al, 1996;Stewart, 1998;Law et al, 2001). Triple-junction instability (i.e., Ingersoll, 1982) may have been the driving force for NW-SE extension (Hendrix and Ingersoll, 1987;Hendrix et al, 2010).…”

Section: Miocene Paleotectonicsmentioning

confidence: 99%

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Paleotectonics of a complex Miocene half graben formed above a detachment fault: The Diligencia basin, Orocopia Mountains, southern California

et al. 2014

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Section: Reversal Of Vertical-axis Rotation and San Gabriel Fault Offsetmentioning

confidence: 82%

Section: Reversal Of Regional Extensionmentioning

confidence: 99%

Section: Reversal Of San Andreas Fault Offsetmentioning

confidence: 99%

Section: Miocene Paleotectonicsmentioning

confidence: 99%

See 2 more Smart Citations

Paleotectonics of a complex Miocene half graben formed above a detachment fault: The Diligencia basin, Orocopia Mountains, southern California

et al. 2014

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“…Upon subduction of the spreading centre, fracture and breakup of the Pacific plate at the offshore margin ensued, beginning with the breakup and sudden rotation of the Monterey microplate 29 Myr (Atwater 1989). The Borderland, Los Angeles region and Mojave Desert subsequently underwent crustal extension and rifting that began 24-18 Myr (Dokka 1989;Tennyson 1989;Wright 1991), accommodated by normal faulting (Crouch & Suppe 1993). Seafloor isochron maps indicate that fracture and formation of the Arguello and Patton microplates began at isochron 6c (24 Myr) at which time the axis of the offshore Pacific-Farallon spreading centre began a steady rotation from NE-SW to NW-SE (finally consistent with San Andreas fault orientation) finishing by 18 Myr and producing arcuate-shaped fracture zones separating the microplates.…”

Section: Introductionmentioning

confidence: 99%

Anisotropy from SKS splitting across the Pacific-North America plate boundary offshore southern California

Ramsay¹,

Kohler²,

Davis³

et al. 2016

Geophys. J. Int.

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S U M M A R YSKS arrivals from ocean bottom seismometer (OBS) data from an offshore southern California deployment are analysed for shear wave splitting. The project involved 34 OBSs deployed for 12 months in a region extending up to 500 km west of the coastline into the oceanic Pacific plate. The measurement process consisted of removing the effects of anisotropy using a range of values for splitting fast directions and delay times to minimize energy along the transverse seismometer axis. Computed splitting parameters are unexpectedly similar to onland parameters, exhibiting WSW-ENE fast polarization directions and delays between 0.8 and 1.8 s, even for oceanic plate sites. This is the first SKS splitting study to extend across the entire boundary between the North America and Pacific plates, into the oceanic part of the Pacific plate. The splitting results show that the fast direction of anisotropy on the Pacific plate does not align with absolute plate motion (APM), and they extend the trend of anisotropy in southern California an additional 500 km west, well onto the oceanic Pacific plate. We model the finite strain and anisotropy within the asthenosphere associated with density-buoyancy driven mantle flow and the effects of APM. In the absence of plate motion effects, such buoyancy driven mantle flow would be NE-directed beneath the Pacific plate observations. The best-fit patterns of mantle flow are inferred from the tomography-based models that show primary influences from foundering higher-density zones associated with the history of subduction beneath North America. The new offshore SKS measurements, when combined with measurements onshore within the plate boundary zone, indicate that dramatic lateral variations in density-driven upper-mantle flow are required from offshore California into the plate boundary zone in California and western Basin and Range.

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Insights from low-temperature thermochronometry into transpressional deformation and crustal exhumation along the San Andreas fault in the western Transverse Ranges, California

et al. 2013

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The San Emigdio Mountains are an example of an archetypical, transpressional structural system, bounded to the south by the San Andreas strike‐slip fault, and to the north by the active Wheeler Ridge thrust. Apatite (U‐Th)/He and apatite and zircon fission track ages were obtained along transects across the range and from wells in and to the north of the range. Apatite (U‐Th)/He ages are 4–6 Ma adjacent to the San Andreas fault, and both (U‐Th)/He and fission track ages grow older with distance to the north from the San Andreas. The young ages north of the San Andreas fault contrast with early Miocene (U‐Th)/He ages from Mount Pinos on the south side of the fault. Restoration of sample paleodepths in the San Emigdio Mountains using a regional unconformity at the base of the Eocene Tejon Formation indicates that the San Emigdio Mountains represent a crustal fragment that has been exhumed more than 5 km along the San Andreas fault since late Miocene time. Marked differences in the timing and rate of exhumation between the northern and southern sides of the San Andreas fault are difficult to reconcile with existing structural models of the western Transverse Ranges as a thin‐skinned thrust system. Instead, these results suggest that rheologic heterogeneities may play a role in localizing deformation along the Big Bend of the San Andreas fault as the San Emigdio Mountains are compressed between the crystalline basement of Mount Pinos and oceanic crust that underlies the southern San Joaquin Valley.

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Pre-transform early Miocene extension in western California

Cited by 33 publications

References 0 publications

Paleotectonics of a complex Miocene half graben formed above a detachment fault: The Diligencia basin, Orocopia Mountains, southern California

Paleotectonics of a complex Miocene half graben formed above a detachment fault: The Diligencia basin, Orocopia Mountains, southern California

Anisotropy from SKS splitting across the Pacific-North America plate boundary offshore southern California

Insights from low-temperature thermochronometry into transpressional deformation and crustal exhumation along the San Andreas fault in the western Transverse Ranges, California

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