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Robert D. Brown

Publications and source records attributed to Robert D. Brown.

8 recordsLinked to original sources
USGS1984

Snow Mountain Wilderness Study Area, California

The Snow Mountain Wilderness study area, located about 120 mi north of San Francisco and on the divide between the Sacramento and Eel Rivers, contains some of the highest terrain in the Coast Ranges. Its mineral-resource potential was evaluated by interpreting data from geologic field studies, from an aeromagnetic survey, from geochemical sampling of stream sediments, rocks, and springs, and from the examination and sampling of prospects. These investigations indicated that there was little promise for the occurrence of mineral or energy resources within the wilderness. New discoveries of unforeseen resources in other parts of the California Coast Ranges or in similar geologic settings elsewhere could prompt renewed study of Snow Mountain, but the nature of such studies cannot be determined now.

California↗
USGS1972

Active faults, probable active faults, and associated fracture zones, San Mateo County, California

As used on this map, the term active fault is defined as a fracture or fracture zone several miles long along which the two sides either are moving relative to one another and parallel to the fracture or are judged likely to move in such fashion within the useful life of existing man-made structures. The judgment that a fault is active may be based on: 1) historic records of surface faulting and earthquake activity, 2) topographic evidence that demonstrates repeated and systematic displacements along the fault trace, 3) systematic displacement of Holocene or Pleistocene geologic units along the fault trace, 4) a linear pattern of small-earthquake activity either along the surface trace of the fault or parallel to it and within 2 miles of the surface trace, or 5) current and measurable systematic displacement across the surface trace of the fault. Most active faults shown on the map are recognized as active on the basis of two or more of these criteria.

California↗
USGS1970

Map showing recently active breaks along the San Andreas Fault between Pt. Delgada and Bolinas Bay, California

This strip map is one of a series of maps showing recently active fault breaks along the San Andreas and other active faults in California. It is designed to inform persons who are concerned with land use near the fault of the location of those fault breaks that have moved recently. The lines on the map are lines of rupture and creep that can be identified by field evidence and that clearly affect the present surface of the land. Map users should keep in mind that these lines are intended primarily as guides to help locate the fault; the mapped lines are not necessarily shown with the precision demanded by some engineering or land utilization needs.

California↗