Golden Gate National Recreation Area, California


Geologic map is derived from: Blake, Jr., M. C., Graymer, R .W., and Jones, D .L. 2000, Geologic Map and Map Database of Parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma Counties, California. U.S. Geological Survey, Miscellaneous Field Studies Map MF 2337; http://pubs.usgs.gov/mf/2000/2337/		Legend of Map Units Qaf - artificial fill Qal - Quaternary alluvium Qc - Coma Formation (Quaternary) Qd - dunes Qmf - fill over marine march Qob - older beach deposits Qs - beach sand Qsr - slope debris and ravine fill Qu - undifferentiated surface deposits	Central “terrane” (Mélange) Jfm - Franciscan complex (Jurassic) mélange Jfmg - Franciscan complex (Jurassic) mélange, graywacke Jfmch - Franciscan complex (Jurassic) mélange, chert Permanente terrane Kfdb - Franciscan complex (Cretaceous) diabase Kfg - Franciscan complex (Cretaceous) graywacke Alcatraz terrane Kfs - Franciscan complex (Cretaceous) sandstone Marin Headlands terrane Jfgs - Franciscan complex (Jurassic) graywacke sandstone Kfgwy - Franciscan complex (Cretaceous) graywacke KJfch - Franciscan complex (Jurassic and Cretaceous) chert sp - Coast Range ophiolite (includes serpentinite)