This part of DS 781 presents data for the paleoshorelines for the geologic and geomorphic map of the Hueneme Canyon and Vicinity map area, California. The vector data file is included in "Paleoshorelines_HuenemeCanyon.zip," which is accessible from
http://pubs.usgs.gov/ds/781/HuenemeCanyon/data_catalog_HuenemeCanyon.html. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., Ritchie, A.C., Kvitek, R.G., Greene, H.G., Krigsman, L.M., Endris, C.A., Clahan, K.B., Sliter, R.W., Wong, F.L., Yoklavich, M.M., and Normark, W.R. (S.Y. Johnson, ed.), 2012, California State Waters Map Series-—Hueneme Canyon and Vicinity, California: U.S. Geological Survey Scientific Investigations Map 3225, 41 p., 12 sheets, scale 1:24,000,
https://pubs.usgs.gov/sim/3225/.
The offshore map area is characterized by two major physiographic features: (1) the nearshore continental shelf and upper slope; and (2) Hueneme Canyon and parts of three smaller, unnamed submarine canyons incised into the shelf southeast of Hueneme Canyon. The nearshore, shelf, and slope are underlain by recent sediments and characterized by active sediment transport. Shelf and slope morphology and evolution result from drainage incision into deltaic sediments of the Oxnard plain during sea-level lowstand, and subsequent sedimentation as sea level rose about 125 to 130 m over the last ~18,000 to 20,000 years (Lambeck and Chappell, 2001). Sea-level rise (controlled by both eustasy and tectonic land-level change) was apparently not steady during this period, leading to development of shorelines during periods of relative sea-level stability. These paleoshorelines, characterized by shoreline angles and adjacent submerged wave-cut platforms and risers (Kern, 1977), are commonly buried by shelf sediment. However, their original morphology is at least partly reserved on the outer shelf and upper slope on the east flank of Hueneme Canyon. The geologic map includes four wave-cut platforms and risers separated by shoreline angles at depths of approximately 65 m, 75 to 85 m, 95 to 100 m, and 120 to 125 m.
References Cited:
Kern, J.P., 1977. J.P., Origin and history of upper Pleistocene marine terraces, San Diego, California: Geological Society of America Bulletin,
v. 88, p. 1553-1566.
Lambeck, K., and Chappell, J., 2001, Sea level change through the last glacial cycle: Science, v. 292, p. 679-686.
To expand geologic mapping to the seafloor within California's State Waters, to update coastal geologic mapping, and to contribute to a uniform regional geologic database. Additionally, to provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the Santa Barbara coastal plain region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore.
