The Santa Barbara Channel area is the western part of the Transverse Ranges geomorphic province and includes the submerged seaward extension of the Ventura basin. A nearly complete post-Jurassic sedimentary sequence is present. The total section ranges from 19,200 to 67,600 ft (5,852 to 20,604 m) in thickness, and average thickness is 35,000 ft (10,668 m). Potential reservoir rocks range from 4,600 to 25,400 ft (1,402 to 7,742 m) in thickness and average 14,000 ft (4,267 m). The section is 30 percent arenaceous.

Geologic structures generally trend west. Anticlinal trends with steeply dipping (up to 75°) flanks are prominent. Numerous near-vertical lateral faults and high-angle reverse faults also are common. Vertical displacements of more than 10,000 ft (3,048 m) and lateral displacements of more than 3 mi (5 km) are recognized.

Twenty-three oil or gas fields are present in the area. Five fields have been discovered on federal lands in the past 2 years, but only one now is being developed. Cumulative production from all fields is over 200 million bbl of oil and nearly 300 billion cu ft of gas.

Statistical approaches to determination of original oil in place in the area have yielded varied results in the magnitude of 25 to 35 billion bbl. Comparisons with other sedimentary basins of the California Coast Ranges indicate that an estimate of 10 to 15 billion bbl of oil in place is probably in the right order of magnitude.