Geology Cafe

Common Rocks of the California Coast Ranges

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rhyolite dacite andesite basalt
Rhyolite
(rounded stream boulder)
extrusive igneous rock
Dacite
(flow-banded lava rock) extrusive extrusive igneous rock
Andesite
(flow-banded lava rock)
extrusive igneous rock

Basalt
(vesicular cinder block)
extrusive igneous rock
granite diorite gabbro limonite
Granite
(boulder with intrusive dikes)
intrusive igneous rock
Diorite
(with xenolith of darker rock)
intrusive igneous rock
Gabbro
(mix of mafic & untramafic minerals)
intrusive igneous rock

Calci-Silicate Rock
(hydrothermally altered rock)
intrusive igneous rock
conglomerate sandstone mudstone siltstone
Conglomerate
(formed from gravel deposit)
sedimentary
Sandstone
(formed from sand deposit)
sedimentary

Mudstone
(formed from seafloor mud)
sedimentary
Siltstone
(rich in quartz silt particles)
sedimentary
limestone travertine marl coal
Limestone
(formed from marine lime mud)
sedimentary
Travertine
(freshwater limestone deposit)
sedimentary
Marl
(marine fossils in mudrock)
sedimentary
Coal
(subbituminous variety)
sedimentary
calcite vein quartz gypsum salt
Calcite
(calcium carbonate crystals)
sedimentary mineral
Quartz
(Silicon dioxide crystals)
sedimentary mineral
Gypsum
(Calcium sulfate crystal)
sedimentary mineral
Rock Salt - Halite
(sodium chlorite crystals)
sedimentary mineral
metasandstone quartzite slate marble
Metasandstone
(metamorphised sandstone)
metamorphic rock
Quartzite
(extremely hard stream cobble)
metamorphic rock
Slate
(metamorphised shale)
metamorphic rock
Marble
(metamorphised limestone)
metamorphic rock
metachert schist gneiss serpentinite
Metachert Breccia
(formed from marine chert)
metamorphic rock
Schist
(showing foliation folding)
metamorphic rock
Gneiss
(showing layered banding)
metamorphic rock
Serpentinite
(Harzburgite with Asbestos)
metamorphic rock
chert greenstone greenschist blueschist
Metachert
(multicolored variety)
metamorphic rock
Greenstone
(formerly basalt)
metamorphic rock
Greenschist
(with blueshist layers)
metamorphic rock

Blueschist
(serpentinite facoid)
metamorphic rock

http://geologycafe.com/rocks/index.html
7/2/2015