Geologic Map of the Santa Monica Mountains, west of the Malibu Ranch, Ventura County, California: Supplement 1 from "Geology of the Santa Monica Mountains, west of the Malibu Ranch, Ventura County, California" (Thesis)

Structurally the western end of the Santa Monica Mountains is a broad east-west anticline with much of its south limb down-faulted beneath the ocean. A parallel series of Vaqueros and Temblor strata are exposed in the fold. Although the series is conformable, there appears to be a distinct lithologic as well as faunal difference between the two formations. Conformably overlying the Temblor is a thick series of lavas and pyroclastics which aggregate about 13,000 feet. The total thickness of the Vaqueros and Temblor sediments is approximately 10,000 feet, and added to this is at least 1,000 feet of intrusive sills. Thus the entire conformable series has an aggregate thickness of about four and one half miles. As might be expected the lower strata are unusually indurated. The Sycamore Canyon fault and its Blue Canyon branch are the major fractures of the area. These faults strike in a northeasterly direction across the trend of the fold and bound a wedge-shaped horst of Vaqueros and Temblor strata between downthrown Temblor rocks on either side.