Report issued by the Bureau of Mines over gold-bearing deposits of Nevada County, California. Drilling and sampling of these gold deposits are discussed. This report includes tables, maps, illustrations, and photographs.

Stratigraphy, structure, and economic geology of parts of Monterey, San Luis Obispo, and San Benito Counties.

From abstract: A composite section of the Silurian, Devonian, and Mississippian formations in the Funeral Mountains between Death Valley and Amargosa Valley is about 4,700 feet thick. The formations are in the top of a concordant, complexly faulted sequence that is about 25,000 feet thick from the highest part of the Precambrian to the Upper Mississippian. The Silurian and younger formations consist of marine dolomite and limestone that contain some regionally characteristic cherty and siliceous clastic beds as well as widely spaced fossiliferous zones.

From introduction: As a result of recently initiated programs such as the San Francisco Bay Region Environment and Resources Planning Study, planners in the San Francisco Bay region are becoming increasingly aware of the types and possible uses earth-science data. These data encompasses a wide spectrum of disciplines including hydrology, topography, geology, geomorphology, and seismology. If properly integrated with the planner's competence in demography, sociology, economics, and other fields, earth-science data can be invaluable for evaluating and controlling many critical environment problems in urban areas.

Abstract: A digital water-quality model of the shallow alluvial aquifer near Barstow was evaluated to determine the applicability of the model computer program to varied hydrolic problems. The evaluation was made on the basis of the data requirements of the model, the characteristics and limitations of the model computer program, the relevance of the model results, and the computer costs associated with the model. Two-well tracer-dilution tests may not be a workable means of determining the aquifer dispersivity and porosity for use in a water-quality model with a large grid interval is under consideration because of the relative insensitivity of such a model to dispersivity. The model results were relevant to the real-life head and water-quality conditions in the aquifer near Barstow and provided an excellent means of evaluating the cause and effect relations associated with ground-water pollution.

None