The southeastern part of the Tejon Quadrangle, California, is of interest to economic geologists for the light its history may throw upon that of near-by-oil-producing and potentially productive regions. The rocks are both crystalline and sedimentary; the sediments, of Tertiary and Quaternary age, aggregate more than 30,000 feet in thickness.

Faulting is the dominant structural feature. The area is divided into three structural units by the Clearwater and the Palomas Canyon faults. The Clearwater fault has had a complex history, both vertical and horizontal movements having occurred at widely separated times. The Palomas Canyon fault shows evidence of vertical displacement only. Other faults of the region are the Violin Canyon, the San Francisquito, the Bee Canyon, and the Whitaker.

Folds observed are the Castaic syncline, the Agua Blanca overturn, and the Elizabeth Lake Canyon upwarp. In addition, numerous small unnamed anticlines and synclines have been mapped.