Lacustrine deposits, intermediate age
Lacustrine deposits, intermediate age
middle Pleistocene
Older fine-grained lacustrine deposits occurring in low-relief and lower elevation parts of basins (e.g., Fremont Valley, in the Mojave immediately south of the El Paso Mountains), as elevated terraces along basin margins (e.g., Mono Basin), and in smaller high alpine basins (e.g., in the northern Sierra near Quincy). Poorly to moderately consolidated, moderately dissected, commonly thinly bedded to laminated clay, silt, and lesser sand, with intercalated coarser beds of fluvial or near-shore deposits. Includes both deeper water and littoral deposits. Locally may include somewhat older and younger lacustrine deposits, and evaporite minerals, beach sand, and gravel deposits.