Marshall, Courtney J. et al. (2012): Sedimentation in an active fold and thrust belt, Santa Barbara Basin, California; local and regional influences on the spatial and temporal evolution of sedimentation from 1.0 Ma to present

Leg/Site/Hole:
ODP 146
ODP 146 893
Identifier:
2013-045108
georefid

Creator:
Marshall, Courtney J.
California State University, Long Beach, Geological Sciences, Long Beach, CA, United States
author

Sorlien, Christopher
University of California, Santa Barbara, United States
author

Nicholson, Craig
author

Behl, Richard
author

Kennett, James
author

Identification:
Sedimentation in an active fold and thrust belt, Santa Barbara Basin, California; local and regional influences on the spatial and temporal evolution of sedimentation from 1.0 Ma to present
2012
In: Anonymous, 2012 AAPG annual convention & exhibition; abstracts volume
American Association of Petroleum Geologists and Society for Sedimentary Geology, Tulsa, OK, United States
2012
Syntectonic sedimentation in the Santa Barbara basin shows significant changes in sediment rate, volume, and depocenter location in the past 1 Ma as a result of local and regional tectonism and related changes in source to sink sediment distribution. This study provides insight into how rapidly, in space and time, deposition relevant to petroleum reservoir distribution can change within a single basin. The prolific east-west-trending Santa Barbara basin is part of an active fold and thrust belt within the Western Transverse Ranges province. Isopach maps defined by distinctive sequence boundaries and other stratigraphic reference horizons identified on deep-penetration industry multichannel seismic reflection (MCS) data, and high-resolution MCS and USGS towed chirp data document dramatic shifts in location, shape, and accumulation rate of sedimentary depocenters in Santa Barbara Channel during the last 1 Myr. Horizon ages were assigned based on correlation to well-dated ODP Site 893, a previously recognized 1-Ma horizon derived from industry well logs, and interpolation between dated tephra layers, biostratigraphic markers, and isotope stage transitions identified from recovered cores that sample strata back to approximately 700 ka. Horizons were interpreted and correlated across the eastern and central basin, extending beyond ODP Site 893, then gridded. Isopach thickness maps were created from the gridded horizons, using a 3D velocity model based on approximately 2 dozen velocity surveys. Sedimentation rates were highest between 1 Ma and approximately 790 ka, but then decreased owing possibly to the initiation of subsidence of the crest of the anticline connecting Anacapa Island to the Santa Monica Mountains, resulting in the initiation of the Hueneme fan. Since approximately 710 ka, sedimentation has been focused within a WNW-ESE-trending offshore footwall basin located between the North Channel and Oak Ridge fault systems. Continued uplift across these two bounding fault systems and further development of the structurally complex northern shelf and south-bounding Mid-Channel anticline is reflected in the 3-dimensional geometry and spatial pattern of sedimentation and constriction of the main central trough. Evolution of these depocenters thus reflects the growth history of faults and folds, and related subsidence, while changes in sedimentation rates reflect the diversion of sediment sourced from the Santa Clara River.
English
Coverage:Geographic coordinates:
North:34.2500
West:-120.3000East: -119.1000
South:34.0000

Sedimentary petrology; absolute age; Anacapa Island; Calabrian; California; Cenozoic; cores; correlation; East Pacific; fold and thrust belts; geophysical methods; Holocene; Leg 146; lithofacies; lower Pleistocene; middle Pleistocene; North Pacific; Northeast Pacific; Ocean Drilling Program; ODP Site 893; Pacific Ocean; Pleistocene; Quaternary; Santa Barbara Basin; Santa Monica Mountains; sedimentation; sedimentation rates; seismic methods; seismic stratigraphy; subsidence; syntectonic processes; tectonics; Transverse Ranges; United States; well logs;

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