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Geologic Map of the Santa Rosa Quadrangle

Geologic Map of the Santa Rosa Quadrangle

California Geological Survey, Regional Geologic Map No. 2A, 1:250,000 scale

Compilation by: D.L. Wagner and E.J. Bortugno


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Natural levee and channel deposits
Basin deposits
Landslide deposits
Dune and beach sand
Intertidal deposits
Older alluvium
Modesto-Riverbank Formations
Terrace deposits
Millerton Formation
Red Bluff Formation
Huichica and Glen Ellen Formations; Includes undifferentiated continental deposits
"Cache Formation"
Clear Lake Volcanics
Tehama Formation
Putah Tuff Member (Ppt)
Ohlson Ranch Formation
Wilson Grove Formation
Unnamed continental deposits
Sonoma Volcanics
Petaluma Formation
Orinda (?) Formation
Pinole Tuff
Drakes Bay Formation
San Pablo Group
Volcanic rocks of Burdell Mtn.
Monterey Group
Gallaway - Skooner Gulch Formations
Putnam Peak Basalt
Laird Sandstone
Iverson Basalt
Markley Sandstone
Nortonville Shale
Domengine Sandstone
Capay Formation
Unnamed Eocene marine rocks
German Rancho Formation
Martinez Formation
Point Reyes Formation
Coastal Belt Franciscan
Gualala Formation
Granitic rocks
Spilite near Black Point
Upper Cretaceous Great Valley Sequence
Upper Cretaceous
Forbes Formation
Guinda Formation
Funks Formation
Sites Formation
Yolo Formation
Venado Formation
Lower Cretaceous Great Valley Sequence
(Marine mudstone, sandstone, and conglomerate) (Klsp-detrital serpentine)
Lower Cretaceous-Upper Jurassic Great Valley Sequence
(Marine mudstone, siltstone, sandstone, and conglomerate) (KJsp-detrital serpentine)
Francisan Complex 
*(Horizontal pattern denotes melange terrane)
Serpentinized ultramafic rocks *(Horizontal pattern denotes melange terrane)
Coast Range Ophiolite
Volcanic rocks, mainly basalt
Gabbro and diabase
Ultramafic rocks (Peridotite) - partly to completely serpentinized
Metamorphic rocks of uncertain age
ls-limestone and marble
Thrust fault
Coast Range thrust (CRT)
Coastal belt thrust (CBT)
Anticlinal fold
Synclinal fold
Strike and dip of beds
Blueschist blocks

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