The petrogenesis and trace-element geochemistry of intermediate lavas from Humphreys Peak, San Francisco volcanic field, Arizona
K.J. Wenrich-Verbeek
1979, Tectonophysics (61) 103-129
The San Francisco Mountain lavas exposed in the upper portion of the southeast slope of Humphreys Peak are composed of three petrographically distinct types: (1) a lower series of hornblende pyroxene andesites; (2) a group of hypersthene dacites; and (3) an upper series of olivine andesites. These rocks have been...
Earthquake recurrence on the Calaveras fault east of San Jose, California
Charles G. Bufe, Philip W. Harsh, Robert O. Burford
1979, Tectonophysics (52) 603-603
Occurrence of small (3 ⩽ ML < 4) earthquakes on two 10-km segments of the Calaveras fault between Calaveras and Anderson reservoirs follows a simple linear pattern of elastic strain accumulation and release. The centers of these independent patches of earthquake activity are 20 km apart. Each region is characterized by a...
Fault-crossing P delays, epicentral biasing, and fault behavior in central California
S.M. Marks, C. G. Bufe
1979, Tectonophysics (52) 600-600
The P delays across the San Andreas fault zone in central California have been determined from travel-time differences at station pairs spanning the fault, using off-fault local earthquake or quarry blast sources. Systematic delays as large as 0.4 sec have been observed for paths crossing the fault at depths of...
Anomalously high uplift rates along the Ventura-Santa Barbara coast, California-tectonic implications
J.F. Wehmiller, A. Sarna-Wojcicki, R. F. Yerkes, K. R. Lajoie
1979, Tectonophysics (52) 380-380
The NW—SE trending segments of the California coastline from Point Arena to Point Conception (500 km) and from Los Angeles to San Diego (200 km) generally parallel major right-lateral strike-slip fault systems. Minor vertical crustal movements associated with the dominant horizontal displacements along these fault systems are recorded in local...
Quaternary crustal deformation along a major branch of the San Andreas fault in central California
G. E. Weber, K. R. Lajoie, J.F. Wehmiller
1979, Tectonophysics (52) 378-379
Deformed marine terraces and alluvial deposits record Quaternary crustal deformation along segments of a major, seismically active branch of the San Andreas fault which extends 190 km SSE roughly parallel to the California coastline from Bolinas Lagoon to the Point Sur area. Most of this complex fault zone lies offshore...
On radon emanation as a possible indicator of crustal deformation
Chi-Yu King
1979, Tectonophysics (52) 120-120
Radon emanation has been monitored in shallow capped holes by a Tracketch method along several active faults and in the vicinity of some volcanoes and underground nuclear explosions. The measured emanation shows large temporal variations that appear to be partly related to crustal strain changes. This paper proposes a model...
Initiation and development of the southern California uplift along its northern margin
R.S. Stein, W. Thatcher, R. O. Castle
1979, Tectonophysics (52) 301-302
Analysis of three first-order leveling lines that traverse the White Wolf fault (site of the 1952 M = 7.7 earthquake), each resurveyed nine times between 1926 and 1974, reveals probable preseismic tilting, major coseismic movements, and a spatial association between these movements and the subsequently recognized southern California uplift. In examining the...
Monitoring massive fracture growth at 2-km depths using surface tiltmeter arrays
M.D. Wood
1979, Tectonophysics (52) 643-643
Tilt due to massive hydraulic fractures induced in sedimentary rocks at depths of up to 2.2 km have been recorded by surface tiltmeters. Injection of fluid volumes up to 4 · 105 liters and masses of propping agent up to 5 · 105 kg is designed to produce fractures approximately 1 km...
Elastic expansion of the lithosphere caused by groundwater withdrawal in south-central Arizona
T.L. Holzer
1979, Tectonophysics (52) 304-304
Relative crustal uplift observed from 1948–1949 to 1967 in the Lower Santa Cruz River Basin in south-central Arizona is attributed at least in part to elastic expansion of the lithosphere induced by the removal, and subsequent loss by evapo transpiration, of 4.35 × 1013 kg of groundwater from alluvium. The area...
Changes in rate of fault creep
P. Harsh
1979, Tectonophysics (52) 519-519
Aseismic slip or fault creep is occurring on many faults in California. Although the creep rates are generally less than 10 mm/yr in most regions, the maximum observed rate along the San Andreas fault between San Juan Bautista and Gold Hill in central California exceeds 30 mm/yr. Changes in slip...
Late Cenozoic uplift of the southwestern Colorado Plateau and adjacent lower Colorado River region
Ivo Lucchitta
1979, Tectonophysics (61) 63-95
Rocks deposited near sea level under marine, estuarine, and lacustrine conditions, and located along the course of the lower Colorado River from the mouth of the Grand Canyon as far as the Mexican border, have been displaced to present positions as high as 880 m a.s.l. and as low as...
Early 20th-century uplift of the northern Peninsular Ranges province of southern California
Spencer H. Wood, Michael R. Elliott
1979, Tectonophysics (52) 249-265
Repeated leveling in the northern Peninsular Ranges province identifies an early 20thcentury episode of crustal upwarping in southern California. The episodic vertical movement is broadly bracketed between 1897 and 1934, and the main deformation is bracketed within 1906–1914 and involved regional up-to-the-northeast tilting of the Santa Ana block of as...
Two areas of probable holocene deformation in southwestern Utah
R.E. Anderson, R.C. Bucknam
1979, Tectonophysics (52) 417-430
Recent geologic studies in southwestern Utah indicate two areas of probable Holocene ground deformation. 1. (1) A narrow arm of Lake Bonneville is known to have extended southward into Escalante Valley as far as Lund, Utah. Remnants of weakly developed shoreline features, which we have recently found, suggest that Lake...
A comparison of long-baseline strain data and fault creep records obtained near Hollister, California
L.E. Slater, Robert O. Burford
1979, Tectonophysics (52) 481-496
A comparison of creepmeter records from nine sites along a 12-km segment of the Calaveras fault near Hollister, California and long-baseline strain changes for nine lines in the Hollister multiwavelength distance-measuring (MWDM) array has established that episodes of large-scale deformation both preceded and accompanied periods of creep activity monitored along...
CDP seismic sections of the western Beaufort continental margin
Stephen Eittreim, Arthur Grantz
1979, Tectonophysics (59) 251-262
The continental rise, slope, and shelf in the Beaufort Sea off northern Alaska were surveyed with 5600 km of common-depth-point (CDP) seismic data by the U.S. Geological Survey in 1977. The lower continental rise consists of a wedge of at least 4.5 km of low-velocity, generally flat-lying, parallel-bedded sediments. Slump-related...
Earliest Phanerozoic or latest Proterozoic fossils from the Arabian Shield
P. Cloud, S.M. Awramik, K. Morrison, D.G. Hadley
1979, Precambrian Research (10) 73-93
We report here the first biologically definable fossils from pre-Saq (pre-Middle Cambrian) rocks of the Arabian Shield. They include the distinctive helically coiled tubular filaments of the oscillatorialean blue-green alga Obruchevella parva as well as two size classes of spheroidal unicells of uncertain affinity. Also present is the conical stromatolite Conophyton and unidentified stromatolites....
Seismic refraction study of the continental edge off the eastern United States
R. E. Sheridan, J. A. Grow, John C. Behrendt, K.C. Bayer
1979, Tectonophysics (59) 1-26
Three long, strike-parallel, seismic-refraction profiles were made on the continental shelf edge, slope and upper rise off New Jersey during 1975. The shelf edge line lies along the axis of the East Coast Magnetic Anomaly (ECMA), while the continental rise line lies 80 km seaward of the shelf edge. Below...
The gravity field of the U.S. Atlantic continental margin
John A. Grow, C.O. Bowin, Deborah R. Hutchinson
1979, Tectonophysics (59) 27-52
Approximately 39,000 km of marine gravity data collected during 1975 and 1976 have been integrated with U.S. Navy and other available data over the U.S. Atlantic continental margin between Florida and Maine to obtain a 10 mgal contour free-air gravity anomaly map. A maximum typically ranging from 0 to +70...
Coal depositional models in some Tertiary and Cretaceous coal fields in the U.S. Western Interior
R. M. Flores
1979, Organic Geochemistry (1) 225-235
Detailed stratigraphic and sedimentological studies of the Tertiary Tongue River Member of the Fort Union Formation in the Powder River Basin, Wyoming, and the Cretaceous Blackhawk Formation and Star Point Sandstone in the Wasatch Plateau, Utah, indicate that the depositional environments of coal played a major role in controlling coal...
Geology and tectonic development of the continental margin north of Alaska
Arthur Grantz, Stephen Eittreim, David A. Dinter
1979, Tectonophysics (59) 263-291
The continental margin north of Alaska, as interpreted from seismic reflection profiles, is of the Atlantic type and consists of three sectors of contrasting structure and stratigraphy. The Chukchi sector, on the west, is characterized by the deep late Mesozoic and Tertiary North Chukchi basin and the Chukchi Continental Borderland....
Anomalous topography on the continental shelf around Hudson Canyon
H.J. Knebel
1979, Marine Geology (33) 67-75
Recent seismic-reflection data show that the topography on the Continental Shelf around Hudson Canyon is composed of a series of depressions having variable spacings (< 100 m to 2 km), depths (1–10 m), outlines, and bottom configurations that give the sea floor an anomalous “jagged” appearance in profile. The acoustic...
Effects of oil transferred from incubating gulls to their eggs
Kirk A. King, C.A. LeFever
1979, Marine Pollution Bulletin (10) 319-321
No. 2 fuel oil, or water, was applied to the breast feathers of incubating laughing gulls trapped at their nest site on an island colony in Texas. Gulls were released after treatment and allowed to incubate their eggs for 5 days. Oil was transferred from the feathers of incubating adults...
Clay mineralogy, fine-grained sediment dispersal, and inferred current patterns, lower Cook Inlet and Kodiak shelf, Alaska
James R. Hein, Arnold H. Bouma, Monty A. Hampton, Ross C. Robin
1979, Sedimentary Geology (24) 291-306
Because lower Cook Inlet and Kodiak shelf are being explored and developed for their petroleum resources, it is essential for environmental reasons to understand the sediment dispersal routes and current patterns. The Susitna River flows into upper Cook Inlet and is the source of clay minerals in Holocene deposits found...
Relationship between physical condition of the carbonate fraction and sediment environments: Northern Puerto Rico shelf
O. H. Pilkey, E.I. Fierman, James V. A. Trumbull
1979, Sedimentary Geology (24) 283-290
Each of three sediment types recognizable on the northern Puerto Rico shelf and beaches is characterized by calcareous material in different physical condition. Dark terrigenous sand is accumulating at a relatively rapid rate and has a carbonate fraction containing fresh-appearing angular particles. The pure-carbonate skeletal-sand sediment type has a much...
Research in the United States relative to geochemistry and health
W.L. Petrie, H.L. Cannon
1979, Physics and Chemistry of the Earth (11) 829-847
Increasing concern regarding the effects of the geochemical environment on health in the United States has fostered research studies in a number of universities and government agencies. The necessity to evaluate the effects of natural and man-made elemental excesses in the environment on health requires the establishment of requirements and...
