Cereza Peak Shale Member of the Peace Valley Formation (revised) of the Ridge Basin Group in the central Ridge basin, Los Angeles Co., CA is named. Clastic wedges of the Ridge Route Formation divide the Peace Valley into five members. Consists of dark-gray shale and blue-gray mudstone containing minor amounts of sandstone interbeds as well as plant, ostracode, and fish fossils. A floral assemblage from the Cereza Peak is representative of a semiarid to subhumid climate. Lateral extent of the unit is 5540 m. Interfingers with the Ridge Route Formation undivided to the northeast and the Violin Breccia to the southwest. Conformably overlies the Frenchman Flat Sandstone Member (new) and conformably underlies the Piru Gorge Sandstone Member (revised) both of the Ridge Route. Thickness at the type section is 914 m and attains 940 m. Age is late Miocene based on fossils. (B1565)

Source: GNU records (USGS DDS-6; Menlo GNULEX).