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Geologic map of the San Bernardino Quadrangle



Geologic map of the San Bernardino Quadrangle


California Geological Survey, Regional Geologic Map No. 3A, 1:250,000 scale

Compilation by: E.J. Bortungno and T.E. Spittler

1986

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DESCRIPTION OF MAP UNITS

Alluvium
Wash deposits
Older wash deposits
Landslide deposits
Wind-blown sand
Younger fan deposits
Fan deposits
Younger alluvium
Lake deposits
Older fan deposits
Older alluvium
Basalt
 - Cinder cone
Glacial till and outwash
Well dissected alluvial fans
Harold Formation and Shoemaker Gravel
Older lake deposits
Continental deposits
San Timoteo Formation
Juniper Hills Formation
Old Woman Sandstone
Crowder Formation
Anaverde Formation
Fernando Formation
Punchbowl Formation
Potatoe Sandstone
Santa Ana Sandstone
Coachella Fanglomerate
Miocene-Pliocene volcanic rocks (b-basalt; t-rhyolite tuff)
Miocene shallow intrusive rocks (a-andesitic; d-dacitic and rhyolitic; b-basaltic)
Glendora Volcanics
(a-andesite; b-basalt; r-rhyolite)
Miocene volcanic rocks
(a-andesite; b-basalt; d-dacite; p-pyroclastic rocks)
Puente Formation
Barstow Formation
Mbv-volcanic rocks
Punchbowl (?) Formation of Cajon Valley
Topanga Formation
Tropico Group
Unnamed Miocene continental deposits
Mcls-limestone and claystone
Pickhandle and Jackhammer Formations
Hector Formation
Vaqueros (?) Formation
Tertiary granitic rocks
Vasquez Formation, volcanic member
Mountain Meadows Biotite, Dacite Porphyry
San Francisquito Formation
San Francisquito (?) Formation
Pelona Schist
MESOZOIC PLUTONIC ROCKS
Cretaceous granitic rocks
Cretaceous quartz diorite
Gabbroic and dioritic rocks
Cretaceous or Jurassic quartz monzonite; Quartz Monzonite of Pleasant View Ridge
Jurassic or Cretaceous granite
Jurassic or Cretaceous granodiorite
Jurassic quartz diorite
Jurassic hornblende diorite and minor gabbro
Jurassic ? monzonite
Mt. Lowe Granodiorite
Triassic monzonite
Gabbro of Pleasant View Ridge
Mesozoic quartzite
Mesozoic metavolcanic rocks
Fairview Valley Formation
Sheared and deformed metamorphic rocks (age uncertain)
Gneiss
Mylonite of Vincent Thrust
"Black Belt" Mylonite
High-grade metamorphic rocks
Upper Paleozoic limestone and marble
Waterman Gneiss
Metasedimentary rocks of uncertain age
ls-limestone and marble
Cambrian and uppermost Precambrian metasedimentary rocks
-Crystalline limestone
-Quartzite
Late Precambrian metasedimentary rocks
-undivided
-Quartzite
Baldwin Gneiss
MAP SYMBOLS
Contact
Fault
Thrust fault
Anticlinal fold
Synclinal fold
Overturned fold
Strike and dip of beds.  General strike and dip of stratified rocks.
Most conspicuous foliation strike and dip
Joints
Dikes


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