Named as member of Pomerado Conglomerate (new) of Poway Group. Is uppermost tongue of sandstone lithosome found entirely within Pomerado Conglomerate in general vicinity of Miramar Reservoir. Although unit is lithologically identical to Mission Valley Formation, Miramar Sandstone Member is nowhere in contact with Mission Valley Formation and therefore is given separate name. Type section designated along fire road extending along ridge at northern margin of Miramar Reservoir [secs.28-29 T14S R2W, Poway 7.5' quad] San Diego Co, CA. Consists of soft medium- to coarse-grained, gray to gray-brown, red-brown weathering sandstone. Thickness is 20 m. Age is late Eocene based on stratigraphic relations.

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