Print this pageAbstract: Physical and Biogenic Characteristics of Sediments from Upper Hueneme Submarine Canyon, California Coast
Twelve box cores were taken in the head of Hueneme submarine canyon from a depth of 14 m to 400 m in July 1974. Hueneme Canyon, at the southern end of the Santa Barbara compartment, funnels sediment into the Santa Monica basin.
Examination of X-ray radiographs, relief casts, and detailed core dissections permits grouping of the 12 cores into 4 types based on primary physical and biogenic sedimentary structures: (1) slightly burrowed and bioturbated, laminated fine-grained sediments; (2) highly burrowed and bioturbated fine-grained sediments; (3) graded sequences; and (4) dense muddy sand.
The sediments are dominantly fine-grained sand and silt with primary modes ranging from 3.5 to 5.0 ^phgr; clay content is negligible. Eight cores exhibit bimodal grain-size distribution. Nine cores contained crude oil ranging from a trace to 3.75 percent by weight, with the highest concentrations at depths of 14, 160, and 250 m.
This suite of cores indicates that transport of sand-sized sediment is channeled along the canyon axis in the head of Hueneme submarine canyon (core types 1 and 3 above). The sediments adjacent to the axis are bioturbated, fine-grained sediments (type 2). Three cores, believed to represent canyon-wall sediment (type 4), are composed of thinly laminated, highly deformed muddy sand.
No evidence of mass-sediment (turbidity) flow is present in these cores. The presence of dominantly fine sand and silt and internal structure such as parallel and ripple lamination suggest low-velocity traction transport of sediments within the head of the canyon.
AAPG Search and Discovery Article #90972©1976 AAPG-SEPM Annual Convention and Exhibition, New Orleans, LA