Late Pliocene deep-water 990 ft (330 m), turbidites of the upper Pico Formation form a well-exposed, nearly complete vertical section in Adams Canyon, California. Approximately 213 ft (700 m) of section were examined in detail, revealing five sectionss of channel-fill sediments up to 386 ft (117 m) thick, dominated by thick-bedded, coarse to fine-grained sandstones, pebbly sandstones, and conglomerates. A thinning of beds upward was found in all five section, along with an associated decrease in grain size. The channel-fill sediments are separated by tens to hundreds of feet (meters) of finer grained plane-parallel interchannel turbidites. The associations of facies types, along with the cyclic nature of the bed thicknesses, indicate that the entire sequence represents a idfan environment of deposition. A comparison with equivalent age midfan channel sediments exposed in Santa Paula Creek, 1.2 mi (2 km) to the east, indicates more frequent deposition for the midfan sediments of Adams Canyon. This is interpreted to be the result of a decrease in the midfan gradient from east to west causing increased deposition of sediment gravity flows in the Adams Canyon area. Paleoecologic studies have indicated an infilling sedimentary basin from early Pliocene time to the beginning of the Pleistocene.

Pebbles and other clast composition indicate the source terrane was Eocene and Miocene sedimentary rocks to the northeast and crystalline basement toward the east. A submarine canyon trending west to southwest is indicated by the paleocurrent data. Flow mechanisms indicated by structures within the section show that sediment was transported by debris, grain, fluidized, and turbulent flows. A rate of 1 mm/year has been estimated as the overall sedimentation rate for the Pliocene sediments in the area.

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