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Mineral Resources > Online Spatial Data > Geology > by state > California Geology

Geologic units in San Diego county, California

[Additional scientific data in this geographic area]

Miocene nonmarine rocks (Oligocene to Pleistocene) at surface, covers 0.5 % of this area

Sandstone, shale, conglomerate, and fanglomerate; in part Pliocene and Oligocene.

Lithology: sandstone; conglomerate; siltstone; mudstone; sedimentary breccia; limestone; dolostone (dolomite); chert; felsic volcanic rock (aphanitic); basalt

Pliocene marine rocks (Miocene to Pleistocene) at surface, covers 2 % of this area

Sandstone, siltstone, shale, and conglomerate; in part Pleistocene and Miocene.

Lithology: sandstone; mudstone; siltstone; claystone; conglomerate

Mesozoic gabbroic rocks, unit 2 (undivided) (Triassic to Cretaceous) at surface, covers 4 % of this area

Gabbro and dark dioritic rocks; chiefly Mesozoic

Lithology: gabbro; diorite

Tertiary volcanic flow rocks, unit 8 (Southern California Basin) (Tertiary (8-25 Ma; most near 15)) at surface, covers < 0.1 % of this area

Tertiary volcanic flow rocks; minor pyroclastic deposits.

Lithology: basalt; andesite; dacite; volcanic breccia (agglomerate); tuff

Tertiary volcanic flow rocks, unit 10 (Alverson) (Tertiary (14-18 Ma)) at surface, covers < 0.1 % of this area

Tertiary volcanic flow rocks; minor pyroclastic deposits.

Lithology: andesite; basalt; pyroclastic

Plio-Pleistocene and Pliocene loosely consolidated deposits (Miocene to Pleistocene) at surface, covers 3 % of this area

Pliocene and/or Pleistocene sandstone, shale, and gravel deposits; in part Miocene.

Lithology: sandstone; conglomerate; claystone; shale; siltstone; limestone; evaporite; coal; sedimentary breccia

Tertiary volcanic flow rocks, unit 11 (Jacumba) (Tertiary (12-19 Ma)) at surface, covers 0.1 % of this area

Tertiary volcanic flow rocks; minor pyroclastic deposits.

Lithology: basalt; andesite; pyroclastic

Upper Cretaceous marine rocks, unit 1 (Upper Great Valley Sequence) (Late Cretaceous) at surface, covers 0.4 % of this area

Upper Cretaceous sandstone, shale, and conglomerate

Lithology: sandstone; mudstone; conglomerate

Jurassic marine rocks, unit 4 (Peninsular Ranges and Western Transverse Ranges) (Paleozoic(?) to Late Jurassic) at surface, covers 0.7 % of this area

Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks

Lithology: argillite; graywacke; quartzite; phyllite; schist; chert; conglomerate; gneiss; amphibolite; marble; limestone; ultramafic

Mesozoic granitic rocks , unit 2 (Peninsular Ranges) (Middle Jurassic to Late Cretaceous) at surface, covers 43 % of this area

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Lithology: tonalite; quartz diorite; granodiorite; quartz monzonite; granite; gneiss; schist; pegmatite

Miocene marine rocks (?) (Miocene(?) or Pliocene(?)) at surface, covers < 0.1 % of this area

Lithology: sandstone; conglomerate

Cretaceous marine rocks (in part nonmarine) (?), unit 2 (Jacumba) (Late Cretaceous(?) to Miocene(?)) at surface, covers < 0.1 % of this area

Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges (?)

Lithology: sandstone; conglomerate

Eocene marine rocks (Paleocene to Oligocene) at surface, covers 4 % of this area

Shale, sandstone, conglomerate, and minor limestone; in part Oligocene and Paleocene.

Lithology: mudstone; sandstone; conglomerate; limestone; siltstone; sedimentary breccia

Mesozoic volcanic rocks, unit 4 (Peninsular Ranges) (Late Jurassic to Early Cretaceous) at surface, covers 5 % of this area

Undivided Mesozoic volcanic and metavolcanic rocks. Andesite and rhyolite flow rocks, greenstone, volcanic breccia and other pyroclastic rocks; in part strongly metamorphosed. Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks

Lithology: felsic volcanic rock; intermediate volcanic rock; mafic volcanic rock; clastic; amphibolite

pre-Cenozoic metasedimentary and metavolcanic rocks undivided (Early Proterozoic to Cretaceous) at surface, covers 1 % of this area

Undivided pre-Cenozoic metasedimentary and metavolcanic rocks of great variety. Mostly slate, quartzite, hornfels, chert, phyllite, mylonite, schist, gneiss, and minor marble.

Lithology: schist; gneiss; quartzite; argillite; phyllite; metavolcanic rock; slate; hornfels; marble; chert; sandstone; mudstone; conglomerate

Schist of various types and ages, unit 1 (Peninsular Ranges) (Triassic(?)) at surface, covers 2 % of this area

Schists of various types; mostly Paleozoic or Mesozoic age; some Precambrian

Lithology: pelitic schist; mica schist; gneiss; quartzite; amphibolite; marble; conglomerate; metavolcanic rock

Quaternary alluvium and marine deposits (Pliocene to Holocene) at surface, covers 18 % of this area

Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.

Lithology: alluvium; terrace; lake or marine deposit (non-glacial)

Eocene nonmarine rocks, unit 2 (Southern California) (middle to late Eocene) at surface, covers 3 % of this area

Sandstone, shale, and conglomerate.

Lithology: conglomerate; sandstone

Miocene marine rocks (Oligocene to Pliocene) at surface, covers 0.7 % of this area

Sandstone, shale, siltstone, conglomerate and breccia; in part Pliocene and Oligocene.

Lithology: sandstone; mudstone; siltstone; evaporite; conglomerate

Cretaceous marine rocks (in part nonmarine), unit 1 (Coast Ranges) (Early to Late Cretaceous) at surface, covers 0.4 % of this area

Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges

Lithology: mudstone; sandstone; conglomerate

pre-Cenozoic granitic and metamorphic rocks undivided (Early Proterozoic to Late Cretaceous) at surface, covers 10 % of this area

Granitic and metamorphic rocks, mostly gneiss and other metamorphic rocks injected by granitic rocks. Mesozoic to Precambrian.

Lithology: plutonic rock (phaneritic); gneiss; metasedimentary rock; metavolcanic rock

Quaternary volcanic flow rocks, unit 8 (Peninsular Ranges) (Quaternary) at surface, covers < 0.1 % of this area

Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.

Lithology: basalt