Publications

A critical part of the exploration for mineral deposits or of quantitative mineral resource assessments is the estimation of how large undiscoveredeposits might be. Typically, this problem is addressed using grade and tonnage models in which a major source of variation in possible sizes is accounted for by the differences in types of deposits (Cox and Singer, 1986; Mosier and Page, 1988...

The lower Miocene Peach Springs Tuff exposed in the Newberry Mountains, California, was deposited within a paleovalley trending S65°W. Exposures within the paleovalley contain lithic breccia intercalated with ash-rich ignimbrite. The clast assemblage of the lithic breccias matches the rock types of the paleovalley walls, and therefore the clasts were not derived from a distant eruptive...

No abstract available.

No abstract available.

The CACTIS (California‐Arizona Crustal Transect Interim Synthesis) workshop in May 1988 brought researchers together in Flagstaff, Arizona, to discuss the geologic evolution and crustal structure of the southern Cordillera between the San Andreas fault in southeastern California and the Colorado Plateau in Arizona [Sass et al., 1988]. The first set of papers resulting from the workshop...

This chapter traces some of the ideas and concepts leading to the current understanding of the process of faulting and earthquake generation, gives examples of engineering geology investigations contributing to that understanding, describes some engineering projects that have been strongly influenced by the process, and suggests needed research. Each of these topics is discussed in...

A contact previously considered to be part of the Sacramento Mountains detachment fault (SDF), exposed in the Sacramento Mountains metamorphic core complex, is reinterpreted as an unconformity between Tertiary rhyolite of Eagle Peak and cataclastically deformed crystalline lower-plate rocks. This reinterpretation is based on outcrop-scale topographic relief and the absence of deformation...

Thousands of people may be killed by landslides each year and property damage may be in the tens of billions of dollars, but the techniques for recognizing and coping with landslides are well developed. Landslides are generally more manageable and predictable than earthquakes, volcanic eruptions, and some storms, but only a few countries have taken advantage of this knowledge to reduce...

A northwest-trending valley in the bedrock surface is buried by firm Pleistocene bay clay, a dense Pleistocene sand layer, soft Holocene bay sediments, loose to dense Holocene beach and dune sands, and artificial fill that have an aggregate maximum thickness of about 90 m (300 ft). Artificial filling of a cove at the site of The Marina District proceeded gradually from the late 1860s to...

A 135‐km‐long, NW‐SE trending, seismic refraction/wide‐angle reflection profile provides a unique along‐strike view of the crustal structure of a belt of metamorphic core complexes in southeastern California: the Whipple, Chemehuevi, and Sacramento mountains metamorphic core complexes. Interpretation of the seismic data was done by two‐dimensional forward modeling of travel times and...

This field trip covers part of the Diablo Range and adjacent San Joaquin Valley of central California (Fig. 1 ). The core of the range is made up of rocks of the Franciscan Complex, flanked by Coast Range ophiolite (CRO) and Great Valley sequence (GVS). The Franciscan Complex in this area consists of deformed and metamorphosed sedimentary and volcanic rocks containing fossils of Late...

No abstract available.