Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.
Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite
Pliocene and/or Pleistocene sandstone, shale, and gravel deposits; in part Miocene.
Older alluvium, lake, playa, and terrace deposits.
Sandstone, shale, siltstone, conglomerate and breccia; in part Pliocene and Oligocene.
Undivided pre-Cenozoic metasedimentary and metavolcanic rocks of great variety. Mostly slate, quartzite, hornfels, chert, phyllite, mylonite, schist, gneiss, and minor marble.
Extensive marine and nonmarine sand deposits, generally near the coast or desert playas
Tertiary volcanic flow rocks; minor pyroclastic deposits.
Undivided Tertiary sandstone, shale, conglomerate, breccia, and ancient lake deposits.
Shale, sandstone, conglomerate, and minor limestone; in part Oligocene and Paleocene.
Sandstone, shale, conglomerate, and fanglomerate; in part Pliocene and Oligocene.
Schists of various types; mostly Paleozoic or Mesozoic age; some Precambrian.
Upper Cretaceous sandstone, shale, and conglomerate
Gabbro and dark dioritic rocks; chiefly Mesozoic
Tertiary intrusive rocks; mostly shallow (hypabyssal) plugs and dikes. Includes some Mesozoic rocks.
Conglomerate, shale, sandstone, limestone, dolomite, marble, gneiss, hornfels, and quartzite; may be Paleozoic in part
Lower Cretaceous sandstone, shale, and conglomerate
Limestone, dolomite, and marble whose age is uncertain but probably Paleozoic or Mesozoic
Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Granitic and metamorphic rocks, mostly gneiss and other metamorphic rocks injected by granitic rocks. Mesozoic to Precambrian.
Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Tertiary pyroclastic and volcanic mudflow deposits.
Selected large landslides, such as Blackhawk slide on north side of San Gabriel Mountains; early to late Quaternary.
Tertiary volcanic flow rocks; minor pyroclastic deposits.
Sandstone, siltstone, shale, and conglomerate; in part Pleistocene and Miocene.
Schists of various types; mostly Paleozoic or Mesozoic age; some Precambrian.
Sandstone, shale, and conglomerate; mostly well consolidated
Undivided pre-Cenozoic metavolcanic rocks. Includes latite, dacite, tuff, and greenstone; commonly schistose.
Undivided Paleozoic metavolcanic rocks. Mostly flows, breccia and tuff, including greenstone, diabase, and pillow lavas; minor interbedded sedimentary rocks
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Franciscan complex: Cretaceous and Jurassic sandstone with smaller amounts of shale, chert, limestone, and conglomerate. Includes Franciscan melange, except where separated--see KJfm.
Ultramafic rocks, mostly serpentine. Minor peridotite, gabbro, and diabase. Chiefly Mesozoic unit 2
Tertiary volcanic flow rocks; minor pyroclastic deposits.
Tertiary volcanic flow rocks; minor pyroclastic deposits.