Analysis of glacier facies using satellite techniques
R.S. Williams Jr., D.K. Hall, C.S. Benson
1991, Journal of Glaciology (37) 120-128
The different snow and ice types on a glacier may be subdivided according to the glacier-facies concept. The surficial expression of some facies may be detected at the end of the balance year by the use of visible and near-infrared image data from the Landsat multispectral scanner...
Trondhjemitic, 1.35-1.31 Ga gneisses of the Mount Holly Complex of Vermont: evidence for an Elzevirian event in the Grenville Basement of the United States Appalachians
N. M. Ratcliffe, J. N. Aleinikoff, W.C. Burton, P. Karabinos
1991, Canadian Journal of Earth Sciences (28) 77-93
A newly recognized suite of trondhjemite–tonalite and dacitic gneiss forms a 10 km wide belt of rocks within the Mount Holly Complex in the central part of the Green Mountain massif of Vermont. Field relationships and chemistry indicate that these gneisses are calc-alkaline, volcanic, and hypabyssal plutonic rocks older than the...
Error in measuring radon in soil gas by means of passive detectors
A.B. Tanner
1991, Nuclear Geophysics (5) 25-30
Passive detection of radon isotopes depends on diffusion of radon atoms from the sites of their generation to the location of the detecting or collecting device. Because some radon decays en route to a passive detector in soil, the radon concentration measured by the detector must be less than the...
Wind generated wave resuspension of sediment in Old Tampa Bay, Florida
David H. Schoellhamer, Victor A. Levesque
Shane Richard M., editor(s)
1991, Conference Paper, Proceedings - National Conference on Hydraulic Engineering
Vertical profiles of velocity and suspended-solids concentration were measured at a scientific instrumentation platform in Old Tampa Bay during the passage of a cold front in March 1990. Strong sustained winds behind the front increased wave activity in the bay, which resulted in resuspension of bottom sediments. The concentration of...
A note on the frictional strength of laumontite from Cajon Pass, California
C.A. Morrow, J.D. Byerlee
1991, Geophysical Research Letters (18) 211-214
Laumontite mineralization is pervasive in joints and shear zones encountered in the Cajon Pass drillhole in southern California. In order to determine whether a gouge composed of this hydrated mineral affects shear strength in a manner similar to low-strength, clay-rich fault gouges, frictional sliding experiments were performed under dry, saturated...
Comparative geometry of the San Andreas Fault, California, and laboratory fault zones
Diane E. Moore, J.D. Byerlee
1991, Geological Society of America Bulletin (103) 762-774
Textural examination of fault gouge deformed in triaxial friction experiments has revealed differences in the orientations of secondary shear sets between the stably sliding and stick-slip samples. In order to determine whether such differences can be identified in natural faults, maps of recently...
Effect of channelization of Rio Puerto Nuevo on ground-water levels in the San Juan metropolitan area, Puerto Rico
Ingrid Padilla
1991, Conference Paper
Channelization and concrete lining of the Rio Puerto Nuevo and its tributaries in the San Juan Metropolitan area has been proposed to control flooding in low lying areas adjacent to the stream. Concern about the effect of these channel modifications on the ground-water system prompted the U.S. Geological Survey in...
Metal bioavailability and toxicity to fish in low-alkalinity lakes: A critical review
D.J. Spry, James G. Wiener
1991, Environmental Pollution (71) 243-304
Fish in low-alkalinity lakes having pH of 6·0–6·5 or less often have higher body or tissue burdens of mercury, cadmium, and lead than do fish in nearby lakes with higher pH. The greater bioaccumulation of these metals in such waters seems to result partly from the greater aqueous abundances of...
Nd, Sr, and O isotopic variations in metaluminous ash-flow tuffs and related volcanic rocks at the Timber Mountain/Oasis Valley Caldera, Complex, SW Nevada: implications for the origin and evolution of large-volume silicic magma bodies
G. L. Farmer, D.E. Broxton, R.G. Warren, W. Pickthorn
1991, Contributions to Mineralogy and Petrology (109) 53-68
Nd, Sr and O isotopic data were obtained from silicic ash-flow tuffs and lavas at the Tertiary age (16-9 Ma) Timber (Mountain/Oasis Valley volcanic center (TMOV) in southern Nevada, to assess models for the origin and evolution of the large-volume silicic magma bodies generated in this region. The large-volume (>900...
An overview of current programs on drug development and regulation for aquaculture: U.S. Fish and Wildlife Service perspective
R. A. Schnick
1991, Veterinary and Human Toxicology (33 Suppl. 1) 4-5
Abstract has not been submitted...
Identification of dissolved-constituent sources in mine-site ground water using batch mixing
Gregory M. Clark, Robert S. Williams Jr.
1991, Water Resources Bulletin (27) 93-100
Batch-mixing experiments were used to help identify lithologic and mineralogic sources of increased concentrations of dissolved solids in water affected by surface coal mining in northwestern Colorado. Ten overburden core samples were analyzed for mineral composition and mixed with distilled water for 90 days until mineral-water equilibrium was reached. Between...
Melting and thermodynamic properties of pyrope (Mg3Al2Si3O12)
C. Tequi, R. A. Robie, B. S. Hemingway, D.R. Neuville, P. Richet
1991, Geochimica et Cosmochimica Acta (55) 1005-1010
The heat capacity of Mg3Al2Si3O12 glass has been measured from 10 to 1000 K by adiabatic and differential scanning calorimetry. The heat capacity of crystalline pyrope has been determined from drop-calorimetry measurements between 820 and 1300 K. From these and previously published results a consistent set of thermodynamic data is presented...
Genesis of sediment-hosted disseminated-gold deposits by fluid mixing and sulfidization: chemical-reaction-path modeling of ore- depositional processes documented in the Jerritt Canyon district, Nevada
A. H. Hofstra
1991, Geology (19) 36-40
Integrated geologic, geochemical, fluid-inclusion, and stableisotope studies of the gold deposits in the Jerritt Canyon district, Nevada, provide evidence that gold deposition was a consequence of both fluid mixing and sulfidization of host-rock iron. Chemical-reaction-path models of these ore-depositional processes confirm that the...
Role of sediment-trace element chemistry in water-quality monitoring and the need for standard analytical methods
Arthur J. Horowitz
1991, Conference Paper, ASTM Special Technical Publication
Multiple linear regression models calculated from readily obtainable chemical and physical parameters can explain a high percentage (70% or greater) of observed sediment trace-element variance for Cu, Zn, Pb, Cr, Ni, Co, As, Sb, Se, and Hg. Almost all the factors used in the various models fall into the category...
Vertical structure of cross-shore currents from wind-induced setup
Guy Gelfenbaum
1991, Conference Paper, Coastal Sediments '91
Most of the storm surge models presented in the literature are vertically averaged and calculate only the sea-surface elevation and mean flow. Whereas these models may be adequate for predicting storm surge heights for flooding purposes, they neglect the vertical structure of the flow and the boundary shear stress, which...
Buried bedrock topography, evidence of overdeepening of Winimusset Brook bedrock valley, and reinterpretation of the extent of glacial Lake Winimusset, Ware quadrangle, Massachusetts
W.W. Lapham, A. Maevsky
1991, Northeastern Geology (13) 69-73
Results from 15 test borings and 8 seismic-refraction surveys in the northeastern quarter of the Ware quadrangle, Massachusetts, provide information on the buried-bedrock topography, evidence of overdeepening of Winimusset Brook valley, information on the thickness and lithology of lacustrine deposits in glacial Lake Winimusset, and indicate a need for reinterpretation...
Electron transport in the dissimilatory iron reducer, GS-15
Y.A. Gorby, Derek R. Lovley
1991, Applied and Environmental Microbiology (57) 867-870
Mechanisms for electron transport to Fe(III) were investigated in GS-15, a novel anaerobic microorganism which can obtain energy for growth hy coupling the complete oxidation of organic acids or aromatic compounds to the reduction of Fe(III) to Fe(II). The results indicate that Fe(III) reduction proceeds through a type b cytochrome...
Preliminary observations on coastal sediment loss through ice rafting in Lake Michigan
E. Reimnitz, E. Hayden, M. McCormick, P. W. Barnes
1991, Journal of Coastal Research (7) 653-664
Shows that ice rafting of sand is an important mechanism influencing processes of coastal erosion and basin-deposition. Ice rafting may be partly responsible for net sediment progradation at this southeastern, lee shore during the last few thousand years, and adds coarse grains to basin muds. -from Authors...
A refinement of the combination equations for evaporation
P. C. D. Milly
1991, Surveys in Geophysics (12) 145-154
Most combination equations for evaporation rely on a linear expansion of the saturation vapor-pressure curve around the air temperature. Because the temperature at the surface may differ from this temperature by several degrees, and because the saturation vapor-pressure curve is nonlinear, this approximation leads to a certain degree of error...
Deep crustal structure of the Precambrian basement beneath northern Lake Michigan, midcontinent North America
W.F. Cannon, Myung W. Lee, W. J. Hinze, K. J. Schulz, Alan G. Green
1991, Geology (19) 207-210
A deep seismic-reflection profile in northern Lake Michigan, midcontinent North America, provides a cross section of the crust across the 1850 Ma Penokean orogen, in which an Early Proterozoic island-arc complex was deformed between two converging Archean continental masses. The island-arc crust is...
Segmentation and the coseismic behavior of basin and range normal faults. Examples from east-central Idaho and southwestern Montana, USA
Anthony J. Crone, Kathleen M. Haller
1991, Journal of Structural Geology (13) 165-176
The range-front normal faults of the Lost River and Lemhi Ranges, and the Beaverhead and Tendoy Mountains in east-central Idaho and southwestern Montana have well-preserved fault scarps on Quaternary deposits along much of their lengths. Fault-scarp morphology, the age of deposits displaced by the faults, and the morphology of the...
Geology of the Bayan Obo iron-rare-earth-niobium deposits, Inner Mongolia, China
L.J. Drew, M. Qingrun, S. Weijun
Anon, editor(s)
1991, Conference Paper, Preprint - Society of Mining Engineers of AIME
The plate tectonic setting, regional geology, and certain aspects of the economic geology of the iron-rare-earth-niobium ore bodies at Bayan Obo, Inner Mongolia, China, were studied by a team of geologists from the Tianjin Geologic Research Academy and the U.S. Geological Survey between 1987 and 1989. These ore bodies were...
Real-time Seismic Amplitude Measurement (RSAM): a volcano monitoring and prediction tool
E.T. Endo, T. Murray
1991, Bulletin of Volcanology (53) 533-545
Seismicity is one of the most commonly monitored phenomena used to determine the state of a volcano and for the prediction of volcanic eruptions. Although several real-time earthquake-detection and data acquisition systems exist, few continuously measure seismic amplitude in circumstances where individual events are difficult to recognize or where volcanic...
Geology and petrology of Mahukona Volcano, Hawaii
D.A. Clague, James G. Moore
1991, Bulletin of Volcanology (53) 159-172
The submarine Mahukona Volcano, west of the island of Hawaii, is located on the Loa loci line between Kahoolawe and Hualalai Volcanoes. The west rift zone ridge of the volcano extends across a drowned coral reef at about-1150 m and a major slope break at about-1340...
On plate tectonics and the geologic evolution of southwestern North America
P.L. Ward
1991, Journal of Geophysical Research (96) 12479-12496
Very rapid subduction of the Farallon plate under southwestern North America between 60 and 40 Ma was accompanied by a relatively low volume of magmatism throughout the southwestern United States and northern Mexico. Between 40 and 20 Ma, when subduction slowed significantly and in one...
