Publications

The ores at Darwin occur as massive replacement bodies in silicated limestones of Pennsylvanian and Permian age adjacent to a Jurassic quartz monzonite stock. Three types of ore have a definite spatial relationship to the quartz monzonite: (1) pyrite-sphalerite-galena ores, (2) pyrite-pyrrhotite-magnetite-sphalerite-galena ores, and (3) galena-Ag-Bi-Se ores.The delta 34 S values of all sulfide min

No abstract available.

Stable isotope and chemical relations have been determined in a typical epithermal Au-Ag deposit located in the Bodie mining district of California. Analyses were made of altered host rocks, vein minerals, alteration clays, fluid inclusions, modern spring waters, and unaltered rocks of the area.The results indicate that a hydrothermal convection system was set up by the interaction of a cooling sh

Recent isotope studies show that the waters involved in a variety of geologic processes are dominantly the local meteoric water of each area. In most active geothermal systems, the D/H ratio of the hot water is nearly identical with the local cold meteoric water, but the O18/O16 ratio has been shifted to a more positive value because of subsurface exchange with rocks.The numerous thermal springs o

No abstract available. 

No abstract available.

With the aid of a linear decision rule, reservoir management and design problems often can be formulated as easily solved linear programing problems. The linear decision rule specifies the release during any period of reservoir operation as the difference between the storage at the beginning of the period and a decision parameter for the period. The decision parameters for the entire study horizon

No abstract available.

This report summarizes existing knowledge on the geohydrology of the Soquel-Aptos area, near, and including the eastern part, of Santa Cruz, California, and outlines work necessary for making a complete appraisal of the water resources of the area.The area is underlain mostly by marine and continental sedimentary deposits of Tertiary and Quaternary age. A small section in the northeastern part of

Water supplies for Pinnacles National Monument are obtained from a collection gallery in alluvium and from a flowing well which obtains water from fractured breccia and tuff near a fault.Rocks other than alluvium, in all but the northern fourth of the monument, are dense igneous or metamorphic types that, unless fractured, have little potential for development of ground water. However, in some are

No abstract available.

After an examination of trends in the modeling of hydrologic systems, a review of some recent studies is given. The authors' preliminary studies on the feasibility and efficiency of the automatic evaluation of catchment model parameters by use of a digital computer are described and some results presented.