Kern River Formation
Kern River Formation
early Pleistocene(?) or Pliocene to Miocene
Consists of fluvial sandstone, conglomerate, and lesser interbedded siltstone and mudstone cropping out across a broad arcuate belt along the foothills-valley transition east and northeast of Bakersfield.
Sandstone is commonly coarse and arkosic and consists predominantly of angular to subrounded quartz and lesser feldspar grains with accessory biotite and minor hornblende, garnet, and pyrite (Bartow and Pittman, 1983). Sandstone and conglomerate units are typically poorly sorted and crudely bedded; grain size grades laterally from coarser proximal deposits in the east and south, to finer distal deposits in the west and north (Bartow and Pittman, 1983).
Maximum thickness is 800 m (measured with subsurface data); lower strata interfinger westward with the marine Etchegoin Formation in subsurface; unconformably overlies the Chanac Formation (included in map unit ben); upper surface is typically deeply dissected and is unconformably overlain by Pleistocene alluvium (Bartow and Pittman, 1983).
Age is late Miocene to Pliocene or early Pleistocene based on stratigraphic relations and presence of Hemphillian age mammalian fauna (Bartow and Pittman, 1983).