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Detailed images of sections of Arguello and Concepcion Canyon Systems
Santa Barbara Anticline
Channel Islands Slope (east)
The basin fill consists of an 8-10 km thick Upper Jurassic to Holocene sedimentary sequence of sand-, silt-, and mudstone that increases to about 14 km in the onshore Ventura part, overlying the Jurassic accretionary sequence of the Franciscan Formation (Dibblee, 1982a, b; Dickinson et al., 1987; Kennedy et al., 1987). Marine sedimentation ended in the eastern Ventura basin during late Pleistocene times (Greene, 1976; Dibblee, 1982b) but continues in the modern offshore section of the basin.
The Santa Barbara Basin forms the foreland of the southward propagating deformation front of the Santa Ynez Mountains, with some of the highest known rates of active tectonic shortening and uplift measured in the Ventura area (Lajoie et al., 1982; Rockwell et al., 1988; Sylvester, 2000). Several of the faults in the mapped area such as the Oak Ridge, South Santa Ynez, Santa Cruz Island, and North Channel Slope faults are considered seismically active (Greene, 1976; Bortugno, 1977; Yerkes et al., 1981; Pinter and Sorlien, 1991; Jennings, 1994).
The Santa Barbara Basin is characterized by a distinct coastal shelf along the mainland and channel islands. The mainland shelf is widest in the eastern part of the channel, narrows west of Gaviota to 4.5 km and widens again forming an 8 km wide promontory southeast of Point Conception. The island shelf is up to 10 km wide.
Note: The triangular "hole" in the basin image is where an oil drilling rig is located. The survey ship cut a wide path around the drilling rig, so there is no data from that area.
Perspective view from the west
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