Release Name: 2005-10-27

Notes: Surficial geology of the Delta area of California by Brian Atwater of the U.S. Geological Survey. Source maps are from the USGS publication MF-1401. This digital version captures surficial geologic units, 1850 tidal wetland areas, late Holocene tidal and non tidal channels, and shorelines of perennial lakes, circa 1910. It does not capture notes or locations of bore holes or outcrops identified by Atwater on the compiled maps.