Studies of the stratigraphy and structure of the Great Valley of California and implications for plate tectonics: Volume One. Subduction-related deformation of the central Great Valley forearc basin. Volume Two. Neogene shortening of the remnant Great Val

The primary goals of this research were to establish a consistent regional stratigraphy in the central Great Valley and to define the regional history of deformation through evaluation of the geometry and kinematic history of major structures. These results can be interpreted to infer the location of previously unrecognized faults, as well as the nature of subduction and configuration of tectonic plates in central California during late Mesozoic and early Cenozoic time.; In this investigation, nine stratigraphic horizons spanning the sedimentary sequence were correlated among 300 wells throughout the central Great Valley. Previously unavailable industry micropaleontology reports from 16 wells served as references from which consistent regional correlations were established.; The regional structural analysis presented herein includes an examination of the Stockton fault and related structures and a reconnaissance investigation of other major structures of the central Great Valley. In this investigation, original stratigraphic correlations were integrated with interpretations of approximately 250 miles of previously unavailable seismic-reflection data and available dipmeters. Well, seismic, and outcrop data were synthesized on a series of structure-contour maps and kinematically restorable cross sections to illustrate fault geometry. Fault-plane piercing points and isopach maps of selected intervals were evaluated to determine the slip history of faults.; The subsurface and outcrop stratigraphy of the central Great Valley were found to change abruptly and significantly across major faults of the region. South of the Stockton fault, thick Upper Cretaceous deep-sea fan turbidite sequences are present, in contrast to coeval deposits north of the fault that are dominated by thin shale-rich intervals. Paleogene strata are not present south of the Stockton fault, where Neogene strata rest directly on upper Cretaceous strata. North of the Stockton fault, a relatively thin sequence of lower to middle Eocene strata unconformably overlies upper Cretaceous strata, and is subsequently overlain disconformably by Neogene strata. Similarly, west of the Midland fault, a thick sequence of lower to middle Eocene strata overlies a thick conformable sequence of Paleocene and upper Cretaceous strata. East of the Midland fault, a relatively thin Eocene sequence rests disconformably on Cretaceous strata.; Evaluation of fault geometry and kinematics indicate that the major faults of the central Great Valley have a multi-phase history of deformation. Down-to-the-south slip occurred along the Stockton fault in late Cretaceous time, followed by a later phase of reverse slip in late Eocene or Oligocene time. Significant strike slip could not be demonstrated along this fault. The reconnaissance investigation of the Freeport fault similarly suggests a late Cretaceous phase of normal slip, with a later phase of reverse slip that may have begun in middle Eocene time. The reconnaissance investigation of the Midland fault zone indicates normal slip during early and middle Eocene time, possibly with a second phase of as much as 1.5 miles of strike slip in Neogene time. There is no evidence for reverse slip on the Midland fault. (Abstract shortened by UMI.)...