Geologic units in Madera county, California

Mesozoic granitic rocks, unit 3 (Sierra Nevada, Death Valley area, Northern Mojave Desert and Transverse Ranges) (Permian to Tertiary; most Mesozoic) at surface, covers 47 % of this area

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Quaternary alluvium and marine deposits (Pleistocene to Holocene) at surface, covers 29 % of this area

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

Older Quaternary alluvium and marine deposits (Pleistocene) at surface, covers 9 % of this area

Older alluvium, lake, playa, and terrace deposits.

Mesozoic volcanic rocks, unit 3 (Mojave Desert, Death Valley area, and Eastern Sierra Nevada) (Triassic to 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.

pre-Cenozoic metasedimentary and metavolcanic rocks undivided (Early Proterozoic to Cretaceous) at surface, covers 4 % 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.

Quaternary glacial deposits (Pleistocene) at surface, covers 2 % of this area

Glacial till and moraines. Found at high elevations mostly in the Sierra Nevada and Klamath Mountains.

Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains) (Triassic to Late Jurassic) at surface, covers 2 % of this area

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

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

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

Tertiary volcanic flow rocks, unit 18 (San Joaquin-Kings Canyon) (Tertiary (3-4 Ma)) at surface, covers 1.0 % of this area

Tertiary volcanic flow rocks; minor pyroclastic deposits.

Quaternary volcanic flow rocks, unit 2 (Long Valley Caldera) (Quaternary) at surface, covers 0.4 % of this area

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

Eocene nonmarine rocks, unit 1 (Northern and Central California) (Eocene) at surface, covers 0.3 % of this area

Sandstone, shale, and conglomerate.

Mesozoic gabbroic rocks, unit 2 (undivided) (Triassic to Cretaceous) at surface, covers 0.2 % of this area

Gabbro and dark dioritic rocks; chiefly Mesozoic

Undivided pre-Cenozoic metavolcanic rocks, unit 2 (undivided) (Paleozoic(?) to Mesozoic(?)) at surface, covers 0.2 % of this area

Undivided pre-Cenozoic metavolcanic rocks. Includes latite, dacite, tuff, and greenstone; commonly schistose.

Tertiary nonmarine rocks, undivided (Paleocene to Pliocene) at surface, covers < 0.1 % of this area

Undivided Tertiary sandstone, shale, conglomerate, breccia, and ancient lake deposits.

Carboniferous marine rocks, unit 8 (Mono Lake) (Ordovician to Devonian) at surface, covers < 0.1 % of this area

Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks

Recent (Holocene) volcanic flow rocks, unit 2 (Mono Craters) (Holocene) at surface, covers < 0.1 % of this area

Recent (Holocene) volcanic flow rocks; minor pyroclastic deposits; in part Pleistocene.