This is the map and geographic data for the updated, "simplified" geologic map of Sonoma Valley Watershed, improving upon the previously available data by utilizing the latest CGS (2006) geology maps. Primary improvements were identification of smaller scale alluvial formations in the valley floor and air fall tuff formations in the mountain belts. This product was created for the purpose of analyzing groundwater recharge potential, and the geologic categories are based on expert opinion about permeability of the geologic units. Data sources: USGSThe United States Geological Survey, http://www.usgs.gov/ 1993 and CGS 2006. The two source data sources were combined because the CGS 2006 was missing a quadrangle. Please see the attached metadata file for more information about the development of the data.
A geology panel consisting of C. Ferrar, R. Lawton, M. Nordberg, W. Haydon, T. Parker, and M. Trotta was convened to determine the simplifying geologic categories and rank them based on similarities in permeability, porosity and fractures.
See also the Sonoma Valley Watershed Groundwater Recharge Potential Technical Report, linked below.
Attachments listed below include:
- Map in 11 X 17 format
- Metadata for ESRI Shapefile
- ESRI Shapefile in ZIPPED format