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Research about Arizona, California

Source-linked reports with geographic coverage including Arizona, California.

At least 55 records · Page 3Linked to original sources
USGS1995

Stratigraphic and structural synthesis of a Miocene extensional terrane, southeast California and west-central Arizona

Detailed stratigraphy and isotopic dating of stratigraphic sections in the Colorado River extensional corridor support a regional correlation of highly faulted Tertiary stratigraphic sequences and provide a chronologic framework for interpreting the evolution of low-angle normal (detachment) faults. On the basis of this correlation, we define six tilting domains in the upper plate of the Whipple, Chemehuevi, and Rawhide detachment faults and identify three discrete episodes of detachment faulting that began in the early Miocene and ended in middle Miocene time. Episodes of rapid detachment faulting are indicated by extreme tilting of upper-plate fault blocks and overlying Miocene sequences, fanning dips of basinal deposits, and angular unconformities that represent short time gaps in the accumulation of syntectonic sequences. During the first episode of detachment faulting at about 20 Ma, the upper plate segmented to form the domains. Basin subsidence and extreme tilting of upper-plate fault blocks and syntectonic deposits characterized the eastern Topock, Crossman, Aubrey, Parker Dam, and Buckskin-Rawhide domains, whereas the western Mopah domain was the site of abundant volcanic activity but no basins or tilting. A second episode of extension at about 18 Ma produced extreme tilts in the Buckskin-Rawhide domain but upper-plate blocks in the Mopah domain tilted moderately. A third regionwide faulting episode between 14 and 12 Ma was due to localized uplift of middle and lower crust and eventual exposure of the detachment faults and their footwalls. The upper-plate fault blocks responded passively to localized slip on the detachment faults. Rapid extension began on the Whipple-Chemehuevi detachment fault at 20 Ma and had shifted southward to the Buckskin-Rawhide detachment fault by 18 Ma; volcanic activity also shifted southward to the Buckskin-Rawhide domain at this time. The southward shift of rapid extension and volcanism probably represents buildup and release of strain at localized sites in the lower plate. Otherwise, stratigraphic and structural relations indicate that the locations of upper-plate basins, faulting and tilting of upper-plate blocks, and position of the breakaway zone remained stable throughout the major phases of extension.

Arizona, California↗
USGS1995

Coachella Valley fringe-toed lizard

Fringe-toed lizards ( Uma spp.) inhabit many of the scattered windblown sand deposits of southeastern California, southwestern Arizona, and northwestern Mexico. These lizards have several specialized adaptations: elongated scales on their hind feet ("fringes") for added traction in loose sand, a shovel-shaped head and a lower jaw adapted to aid diving into and moving short distances beneath the sand, elongated scales covering their ears to keep sand out, and unique morphology (form or structure) of internal nostrils that allows them to breathe below the sand without inhaling sand particles. While these adaptations enable fringe-toed lizards to successfully occupy sand dune habitats, the same characteristics have restricted them to isolated sand "islands." Three fringe-toed lizard species live in the United States: the Mojave ( U. scoparia ), the Colorado Desert ( U. notata ), and the Coachella Valley ( U. inornata ). Of the three, the Coachella Valley fringe-toed lizard has the most restricted range and has been most affected by human activities. In 1980 this lizard was listed as a threatened species by the federal government.

Arizona, California↗
USGS1989

Paleomagnetism and tectonic rotation of the lower Miocene Peach Springs Tuff: Colorado Plateau, Arizona, to Barstow, California

We have determined remanent magnetization directions of the lower Miocene Peach Springs Tuff at 41 localities in western Arizona and southeastern California. An unusual northeast and shallow magnetization direction confirms the proposed geologic correlation of isolated outcrops of the tuff from the Colorado Plateau to Barstow, California, a distance of 350 km. The Peach Springs Tuff was apparently emplaced as a single cooling unit about 18 or 19 Ma and is now exposed in 4 tectonic provinces west of the Plateau, including the Transition Zone, Basin and Range, Colorado River extensional corridor, and central Mojave Desert strike-slip zone. As such, the tuff is an ideal stratigraphic and structural marker for paleomagnetic assessment of regional variations in tectonic rotations about vertical axes. From 4 sites on the stable Colorado Plateau, we have determined a reference direction of remanent magnetization (I = 36.4°, D = 33.0°, α 95 = 3.4°) that we interpret as a representation of the ambient magnetic field at the time of eruption. A steeper direction of magnetization (I = 54.8°, D = 22.5°, α 95 = 2.3°) was observed at Kingman where the tuff is more than 100 m thick, and similar directions were determined at 7 other thick exposures of the Peach Springs Tuff. The steeper component is presumably a later-stage magnetization acquired after prolonged cooling of the ignimbrite. When compared to the Plateau reference direction, tilt-corrected directions from 3 of 6 sites in the central Mojave strike-slip zone show localized rotations up to 13° in the vicinity of strike-slip faults. The other three sites show no significant rotations with respect to the Colorado Plateau. Both clockwise and counterclockwise rotations were measured, and no systematic regional pattern is evident. Our results do not support kinematic models which require consistent rotation of large regions to accommodate the cumulative displacement of major post-middle Miocene strike-slip faults in the central Mojave Desert. Most of our sites in the Transition Zone and Basin and Range province have had no significant rotation, although small counterclockwise rotation in the McCullough and New York Mountains may be related to sinistral shear along en echelon faults southwest of the Lake Mead shear zone. The larger rotations occur in the Colorado River extensional corridor, where 8 of 14 sites show rotations ranging from 37° clockwise to 51° counterclockwise. These rotations occur in allochthonous tilt blocks which have been transported northeastward above the Chemehuevi-Whipple Mountains detachment fault. Upper-plate blocks within 1 km of the exposed detachment unexpectedly show no significant rotation. From this relation, we infer that rotations are accommodated along numerous low-angle faults at higher structural levels above the detachment surface.

Arizona, California↗
USGS1986

Evapotranspiration estimates using remote-sensing data, Parker and Palo Verde Valleys, Arizona and California

In 1981 the U.S. Geological Survey established an experimental project to assess the possible and practical use of remote sensing data to estimate evapotranspiration as an approximation of consumptive use in the lower Colorado River flood plain. The project area was in Parker Valley, Arizona. The approach selected was to measure the areas covered by each type of vegetation using remote sensing data in various types of analyses and to multiply each area by a predetermined water use rate. Two calibration and six remote sensing methods of classifying crop types were compared for cost, accuracy, consistency, and labor requirements. Included were one method each for field reconnaissance using 1982 data, low altitude (< than 5,000 ft) aerial photography using 1982 data, and visual photointerpretation of Landsat satellite images using 1981 and 1982 data; two methods for medium-altitude (15,000-18,000 ft) aerial photography using 1982 data; and three methods for digital Landsat satellite images using 1981 data. A test of the most promising digital processing method, which used three image dates, was made in part of Palo Verde Valley, California, where 1981 crop data were more complete than in Parker Valley. Of the eight methods studied, the three-date digital processing method was the most consistent and least labor-intensive; visual photointerpretation of Landsat images was the least expensive. Evapotranspiration estimates from crop classifications by all methods differed by a maximum of 6%. Total evapotranspiration calculated from crop data and phreatophyte maps in 1981 ranged from 12% lower in Palo Verde Valley to 17% lower in Parker Valley than consumptive use calculated by water budgets. The difference was greater in Parker Valley because the winter crop data were not included. (Author 's abstract)

Arizona, California↗
USGS1985

Sequentially and alternatively developed heights for two representative bench marks: near Palmdale, California and along the Bill Williams River, Arizona

This report consists chiefly of 41 tables that both describe and fully document the reconstructions of a series of alternately developed heights based on levelings leading into two representative bench marks in the southwestern United States. One of these marks, 3219, Vincent, California (fig. 1), lies within the area of the Pacific-North American plate boundary; the other, 22Q, Bill Williams River, Arizona (fig. 1), falls within what is believed to be a singularly stable section of southwestern Arizona. Because the levelings that produced these heights were characterized by especially disparate routes with respect to both terrain and climate, the resulting heights provide a test for the existence and magnitude of path-dependent error in geodetic leveling. These two marks were chosen both because of their relative stability with respect to adjacent marks and because their tectonic stability (or instability) can be inferred from the geologic record. Specifically, we can reasonably speculate that 3219 may have sustained measurably significant tectonic displacements during the 20th century, whereas 22Q probably has remained virtually invariant with respect to any fixed datum during the same period. Bench mark 3219 is a standard Geological Survey iron post stamped "3219" near the Southern Pacific Railroad station at Vincent (U.S. Geological Survey, 1898, p. 392); 22Q is a brass cap stamped "22Q (MWD)" set in a concrete post located in a gully immediately north of the Bill Williams River, Arizona (USC&GS Quad. 34114). 3219 was established by the Geological Survey no later than 1897 (Gannett and Baldwin, 1907, p. 365); 22Q was established by the Metropolitan Water District of southern California in advance of the 1931 control surveys along the projected route of the Colorado River Aqueduct.

Arizona, California↗
USGS1983

Correlation of metamorphosed Paleozoic strata of the southeastern Mojave Desert region, California and Arizona

Isolated outcrops of deformed, regionally metamorphosed Paleozoic strata are scattered within the southeastern Mojave Desert region of California and western Arizona. These strata unconformably overlie a basement of Proterozoic crystalline rocks and are overlain in turn by metamorphosed Mesozoic sedimentary rocks. The strata can be correlated lithostratigraphically with the classic cratonal Paleozoic section of the western Grand Canyon, Arizona, and with nonmetamorphosed Paleozoic sections transitional between cratonal and miogeoclinal in the Ship, Marble, and Providence Mountains, California. The strata evidently were once continuous with Paleozoic epicontinental strata exposed throughout the southern Great Basin and Colorado Plateau. Outcrops of Paleozoic strata and of the underlying Proterozoic basement in the southeastern Mojave Desert region define a terrane that has been disrupted by Mesozoic thrust faults and by Tertiary detachment faults but that nevertheless retain a gross paleogeographic coherence. This coherent terrane extends at least as far west and southwest as the Big Maria, Palen, and Calumet Mountains, and possibly beyond to include Paleozoic exposures in the San Bernardino Mountains and near Victorville. Poorly understood tectonic boundaries separate the area of paleogeographic coherence from known or suspected allochthonous terranes in the western Mojave Desert and the eastern Transverse Ranges.

Arizona, California↗
USGS1983

Preliminary map of limonitic hydrothermal alteration for portions of the Needles 1° x 2° quadrangle, Arizona and California

Portions of the Needles quadrangle have been designated by the Bureau of Land Management as potential wilderness areas and are being evaluated by a multidisciplinary team to determine the mineral-resource potential. As a part of this study Landsat images are being used to map the generalized distribution of limonitic materials as a guide to hydrothermal alteration which, in turn, acts as a guide to mineralized systems. The term limonite, defined by Blanchard (1968) as a general term for hydrous iron oxides, is here modified to include any material with the unique spectral reflectance properties of the ferric oxide minerals such as hematite and goethite, as defined by Hunt (1980). The map shows areas of limonitic hydrothermal alteration but does not show hydrothermally altered areas lacking limonitic materials. Table 1 lists, for each hydrothermally altered area detected, the type of alteration and the anomalous trace-element geochemical suite found in that area.

Arizona, California↗