Alluvium, intermediate age
Alluvium, intermediate age
middle Pleistocene
Intermediate age fluvial deposits mainly occurring on elevated terraces and intermediate age alluvial fans. Predominantly includes coarser alluvial fan material of intermediate age, with lesser early- and late-Pleistocene alluvium. Weakly to moderately consolidated; generally moderately dissected; generally moderately to poorly sorted; grain size is variable and includes gravel (pebble to cobble and minor boulder), sand, silt, and lesser clay. Composition highly variable and dependent on source rock types. Locally includes somewhat older and younger alluvium, undifferentiated glacial outwash, lacustrine, eolian, talus, colluvial, and debris flow deposits. Includes Riverbank, Friant, and Red Bluff Formations (Diller, 1894; Marchand and Allwardt, 1981), and many undifferentiated intermediate age alluvial units from map sources.