Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
National Earthquake Hazards Reduction Program, summaries of technical reports; Volume XXXIII
No abstract available.
Authors
Muriel L. Jacobson
Impact origin of the Avak Structure, Arctic Alaska, and genesis of the Barrow gas fields
Geophysical and subsurface geologic data suggest that the Avak structure, which underlies the Arctic Coastal Plain 12 km southeast of Barrow, Alaska, is a hypervelocity meteorite or comet impact structure. The structure is a roughly circular area of uplifted, chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter that is bounded by a ring of anastomosing, inward
Authors
C.E. Kirschner, Arthur Grantz, M. W. Mullen
The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical, geophysical, and mineral resource maps of the Ajo and Lukeville 1° by 2° quadrangles, Arizona
Encompassing about 21,000 km2 in southwestern Arizona, the Ajo and Lukeville 1° by 2° quadrangles have been the subject of mineral resource investigations utilizing field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat imagery. The results of these studies are published as a folio of maps, figures, and tables, with accompanying discussions. Past mineral
Authors
Floyd Gray, R. M. Tosdal, J.A. Peterson, D. P. Cox, R. J. Miller, D. P. Klein, P. K. Theobald, G. B. Haxel, M. J. Grubensky, G. L. Raines, H. N. Barton, D.A. Singer, R. G. Eppinger
Introduction to special section on the California-Arizona crustal transect: CACTIS, Part 3
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 appeared in
Authors
R. W. Simpson, Keith A. Howard, Gordon B. Haxel
A reinterpretation of the timing, position, and significance of part of the Sacramento Mountains detachment fault, southeastern California
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 along the
Authors
Carol Simpson, Janet Schweitzer, Keith A. Howard
Faulting and seismic activity
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 sequence.The un
Authors
Manuel G. Bonilla
The Marina District, San Francisco, California: Geology, history, and earthquake effects
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 1912, when
Authors
Manuel G. Bonilla
Franciscan Complex, Coast Range ophiolite and Great Valley sequence: Pacheco Pass to Del Puerto Canyon, California
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 Jurassic to L
Authors
Allan P. Bennison, M. Clark Blake, B. F. Cox, William P. Elder, W. G. Ernst, Tekla Harms, T. H. Nilsen
Field Trip 9: San Francisco to Point Reyes: Both sides of the San Andreas fault
No abstract available.
Authors
J. C. Clark, Clyde Wahrhaftig, E. E. Brabb
An axial view of a metamorphic core complex: Crustal structure of the Whipple and Chemehuevi Mountains, southeastern California
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 amplitudes. T
Authors
J. M. Wilson, Jill McCarthy, R.A. Johnson, Keith A. Howard
The world landslide problem
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 landslide h
Authors
E. E. Brabb
Seismic reflection/refraction mapping of faulting and regional dips in the eastern Alaska Range
We present the results of a Trans‐Alaska Crustal Transect (TACT) investigation of the upper 2–5 km of the eastern Alaska Range in the vicinity of the Denali fault based on seismic reflection/refraction data, laboratory measurements of rock velocities, and structural mapping. The Denali fault is a major dextral slip structure mappable for more than 2000 km separating the Wrangellia and adjacent ter
Authors
Thomas M. Brocher, Warren J. Nokleberg, N.I. Christensen, William J. Lutter, Eric L. Geist, M. A. Fisher