|Repetto Formation, Los Angeles Basin
Percent shale of the Repetto Formation is calculated from the isopach of the nonsandstone fraction, termed "siltstone-silty shale" by Conrey (1967). The greatest percentage of shale occurs in the east part of the Los Angeles Basin, where there are more than 3,000 ft (>914.6 m) of fine-grained deposits. Percent shale decreases toward the north part of the basin, near the conglomeratic mid- to upper fan facies (Redin, 1991).
Conrey, B. L., 1967, Early Pliocene sedimentary history of the Los Angeles Basin, California: California Division of Mines and Geology Special Report 93, 63 p.