Correlation between the geologic record and computed plate motions for central California

Abstract

We have attempted to correlate geologic events in part of central California with computed motions of oceanic plates relative to cratonic North America. Three composite terranes are considered: (1) the Sierra Nevada, (2) the Coast Ranges northeast of the San Andreas fault, and (3) the Salinian block. In the Sierra Nevada, Jurassic plutonism (ending about 147 m.y. B.P.) and Cretaceous plutonism (120–80 m.y. B.P.) correlate with deduced Farallon‐North America (FA:NA) convergence, as does the Nevadan orogeny (158–153 m.y. B.P.). However, the gap in plutonism 146–121 m.y. B.P. outlasted by far an apparent minimum in convergence (145–135 m.y. B.P.). Magmatism ceased in the Sierra and uplift slowed during the Laramide orogeny 75–45 m.y. B.P. when tectonic activity had moved east to the site of the Rockies, presumably because of a low angle of subduction, but volcanisin resumed in the Sierra about 33 m.y. B.P., indicating that a steeper angle was reestablished. Apparently east‐west compression slackened when the Pacific‐North America (PA:NA) transform regime developed. Basalt was erupted in the southern Sierra 12–3 m.y. B.P., and during this same time, the range started its most rapid rise as a normal‐fault‐bounded block. The Coast Ranges north‐east of the San Andreas fault are underlain by the Franciscan Complex. The older parts of the Complex were probably assembled in a subduction zone far south of their present location, but we believe that the same FA:NA convergence that was cited for Sierran plutonism was responsible, despite the disparity in latitude, as the Farallon plate was probably in contact with most of the western margin of North and South America. A perceived strong pulse in convergence 100–85 m.y. B.P. evidently produced the Coast Range thrust which on geologic grounds alone, most likely originated between 96 and 88 m.y. B.P. Some of the northwesterly transport of Franciscan rocks relative to North America is ascribed to oblique Kula‐North America (KU:NA) convergence 85–43 m.y. B.P., during which period the Coast Range thrust was revived about 60 m.y. B.P. The Farallon plate again influenced the California margin after the KuIa plate had moved northward, and FA:NA convergence caused the accretion of the Coastal Belt and King Range terranes of the neo‐Franciscan. The advent of Pacific‐North America (PA:NA) interaction was marked by local volcanism which advanced from the southeast toward the northwest in consonance with the passage of the Mendocino triple junction (Dickinson and Snyder, 1978). In the Salinian block, plutons 107–82 m.y. old can be ascribed to the same FA:NA convergence as the contemporary Cretaceous plutons of the Sierra Nevada, although the Salinian intrusives originated much farther south. Paleomagnetic results (Champion et al., 1980) from the Salinian‐related Pigeon Point Formation, 75–71 (?) m.y. in age, suggest about 2500 km of poleward (essentially coastwise) movement. This postulated large movement during part (or all?) of the last 75 m.y. poses the greatest dilemma in our study. Th...

Seismic Determination of Reservoir Heterogeneity: Application to the Characterization of Heavy Oil Reservoirs

“…The fast convergence rate is also observed by the presence of relatively displaced arc magmatism eastward from the Sierra Nevada into Colorado (Lipman et al, 1972;Cross and Pilger, 1978). This oblique subduction at the central California margin continued until end of the Eocene when the Farallon plate displaced the Kula plate (Page and Engebretson, 1984). A decrease in convergence rates in the late Eocene-Oligocene periods steepened the subduction zone and the volcanism, associated with the subduction process, migrated southwestward from Idaho and Montana into Nevada (Lipman et al, 1972;Cross and Pilger, 1978).…”

“…A subduction zone has prevailed at the western margin of North America during Cenozoic times when the oceanic Kula plate subducted obliquely under the North American plate (Page and Engebretson, 1984). Bartow (1991) proposed that the rapid rate of convergence might have made this subduction zone to be of low angle.…”

Facies architecture and provenance of a boulder-conglomerate submarine channel system, Panoche Formation, Great Valley Group: A forearc basin response to middle Cretaceous tectonism in the California convergent margin

“…100 Ma) has received particular attention as an opportunity to examine how a convergent system responded to changes in plate motion rates and direction. Many studies have documented an overall increase in plate convergence rate and plate motion parallel to the arc (obliquity) occurring 100-90 Ma (Page and Engebretson, 1984;Engebretson et al, 1985;Liu et al, 2008). Others suggest that these plate motion changes led to induced deformation in the eastern Sierran arc, resulting in increased rates of magmatism (Glazner, 1991;Tikoff and Teyssier, 1992;McNulty, 1995;Greene and Schweickert, 1995;Tikoff and Greene, 1997;Tobisch et al, 2000;Memeti et al, 2014;Paterson and Ducea, 2015), as well as accelerated phases of accretion in the prism (Wakabayashi, 2015).…”

Summary of geology and petroleum plays used to assess undiscovered recoverable petroleum resources of Los Angeles Basin Province, California

“…Oblique subduction with a northerly to northeasterly convergence direction from latest Cretaceous through Paleocene or early Eocene (Engebretson and others, 1985;Page and Engebretson, 1984;Nilsen and Clarke, 1975;Dickinson and others, 1979;Bartow, 1987), while generally evident in the geologic record of central California, is less apparent in the sparse and fragmented Paleocene rocks of southern California that appear to be allochthonous, having been deposited on terrane moved northward and accreted to southern California in post-Late Paleocene time (Nilsen, 1987;Howell and others, 1987). Basal unconformities in the Santa Monica and Santa Ana Mountains suggest a period of probable vertical tectonism during Paleocene (Yerkes and others, 1965;Vedder, 1987).…”