Named for Poverty Flat, shallow broad valley just east of California Aqueduct south of Orestimba Creek, CA. Type section designated along California Aqueduct, secs.20,29,32 T7S R8E, Newman 7.5' quad, Stanislaus Co, CA. Name "Poverty Flat" first used for undifferentiated unit by Collins (1950). As defined includes "undifferentiated Miocene between Garzas and Cow Creeks" of Anderson and Pack (1915) and basal conglomerate and conglomeratic sandstone of San Pablo Formation of Anderson and Pack (1915). Reference section is in subsurface of Texaco Howard No.1 well about 25 km east of type section. Lower part composed of gray or blue-gray lithic sandstone; upper part composed of interbedded light-gray to white kaolinitic quartz sandstone, siltstone, carbonaceous shale, and kaolinitic claystone. Is approximately 125 m thick at type. Lower part contains diatoms of late middle Eocene age and molluscan assemblage of late Eocene or early Oligocene age. Age of unit considered to be late middle and late Eocene.

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