Fabric and its relation to sedimentologic and physical properties of near-surface sediment, Shelikof Strait and Alsek prodelta, Alaska
M.E. Torresan, W. C. Schwab
1987, Journal of Sedimentary Petrology (57) 408-418
To investigate the possible relation between the fabric (microstructural arrangement of particles) of a fine-grained sedimentary deposit and the depositional and environmental processes of that deposit, the fabric of sediment samples from the sea floor of two different depositional settings, Shelikof Strait and...
Relation of long- and short-term atmospheric sulfur concentrations to sulfate deposition in New York State
C.R. Barnes
1987, Northeastern Environmental Science (6) 89-98
Records from 1965-80 indicate an annual decrease of 1.9% in sulfur dioxide emissions upwind of New York, an annual decrease of 1.5% in atmospheric particulate sulfate concentration in New York, and an annual decrease of 2.0% in sulfate-deposition rate in New York. Sulfate-deposition rates in bulk sampling in New York...
Geochemistry, mineralogy, and petrogenesis of basalt from the Gorda Ridge
A. S. Davis, D.A. Clague
1987, Journal of Geophysical Research Solid Earth (92) 10467-10483
Basalt pillow lava with glassy rims was dredged from 17 sites along the Gorda Ridge between latitudes 43°N and 40.8°N. All samples are low-K2O mid-ocean ridge tholeiitic basalt having a narrow compositional range with Mg numbers clustered around 60–62; more primitive and evolved compositions are present but rare. None of...
Testing the consistency for mapping urban vegetation with high-altitude aerial photographs and landsat MSS data
Franklin G. Sadowski, James A. Sturdevant, Rowan A. Rowntree
1987, Remote Sensing of Environment (21) 129-141
Two methods of analysis were evaluated for mapping urban vegetation on high-altitude, color-infrared aerial photographs and Landsat MSS data of Syracuse, NY. The first method consisted of defining the spatial patterns (strata) of urban vegetation occurrence. The second method discriminated woody and herbaceous vegetation classes within defined strata. Emphasis was...
CHANGES IN GRADE, VOLUME AND CONTAINED GOLD DURING THE MINING LIFE-CYCLE OF GOLD PLACER DEPOSITS.
J. D. Bliss, G. J. Orris, W. D. Menzie
1987, CIM Bulletin (80) 75-80
Analysis of gold placer data throughout the world suggests that gold grades and volumes cannot be used to distinguish between most types of gold placers. Only the alluvial plain and fan placers are significantly different among the types of gold placers considered. Gold grades and volumes change when working placers...
Diagenetic palaeotemperatures from aqueous fluid inclusions: re-equilibration of inclusions in carbonate cements by burial heating
R.C. Burruss
1987, Mineralogical Magazine (51) 477-481
Diagenetic palaeotemperatures determined from aqueous fluid inclusions can be affected by re-equilibration during burial heating. Calculations based on the observed behaviour of inclusions in fluorite under external confining pressure allows prediction of the temperatures and depths of burial necessary to initiate re-equilibration of aqueous inclusions in the common size range...
PYROLYSIS/GAS CHROMATOGRAPHY/MASS SPECTROMETRY OF A SERIES OF BURIED WOODS AND COALIFIED LOGS THAT INCREASE IN RANK FROM PEAT TO SUBBITUMINOUS COAL.
Patrick G. Hatcher, Harry E. Lerch, Rama K. Kotra, Vincent T. Verheyen
1987, Conference Paper, ACS Division of Fuel Chemistry, Preprints
To better understand the coalification process, we have conducted numerous studies of the chemical structural composition of xylem tissue from gymosperm wood and related woods that has been coalified to varying degrees. The studies presented here, examine the chemical nature of buried and coalified xylem tissue at the molecular level....
Solid-state 13C NMR studies of dissolved organic matter in pore waters from different depositional environments
William H. Orem, Patrick G. Hatcher
1987, Organic Geochemistry (11) 73-82
Dissolved organic matter (DOM) in pore waters from sediments of a number of different depositional environments was isolated by ultrafiltration using membranes with a nominal molecular weight cutoff of 500. This > 500 molecular weight DOM represents 70–98% of the total DOM in these pore waters. We determined the gross...
The decarbonation and heat capacity of ZnCO3
H.T. Haselton, J. R. Goldsmith
1987, Geochimica et Cosmochimica Acta (51) 261-265
The decarbonation curve for ZnCO3 has been determined in the pressure range 3–20 kbar by using a combination of cold-seal vessels and piston-cylinder apparatus with NaCl assemblies. Heat capacities for both synthetic and natural ZnCO3 samples were measured by differential scanning calorimetry at temperatures ranging from 340 to 497 K. The results...
Ice erosion of a sea-floor knickpoint at the inner edge of the stamukhi zone, Beaufort Sea, Alaska
P. W. Barnes, J.L. Asbury, D.M. Rearic, C.R. Ross
1987, Marine Geology (76) 207-222
In 1981 and 1982, detailed bathymetric and side-scan sonar surveys were made of an area of the sea floor north of Prudhoe Bay, Alaska, to study the changing characteristics of the seabed at the inner boundary of the stamukhi zone, the...
The hydrothermal system of the Calabozos caldera, central Chilean Andes
A.L. Grunder, J. M. Thompson, W. Hildreth
1987, Journal of Volcanology and Geothermal Research (32) 287-298
Active thermal springs associated with the late Pleistocene Calabozos caldera complex occur in two groups: the Colorado group which issues along structures related to caldera collapse and resurgence, and the Puesto Calabozos group, a nearby cluster that is chemically distinct and probably unrelated to the Colorado springs. Most of the...
The relation of stream sediment surface area, grain size and composition to trace element chemistry
A. J. Horowitz, K. A. Elrick
1987, Applied Geochemistry (2) 437-451
Intensive studies of 17 geographically and hydrologically diverse stream bed sediments provide information on the relation between grain size, surface area, and operationally defined geochemical phases (e.g. Mn oxides, amorphous Fe oxides) to trace element concentrations. Of the size fractions investigated...
The chemical, physical and structural properties of estuarine ice in Great Bay, New Hampshire
D.A. Meese, A. J. Gow, P.A. Mayewski, W. Ficklin, T.C. Loder
1987, Estuarine, Coastal and Shelf Science (24) 833-840
The purpose of this study was to provide general information on the chemical, physical and structural properties of estuarine ice and show how it compares with sea ice found at higher latitudes in order to determine whether the ice in Great Bay can be used as an analog in the...
Subsidence, crustal structure, and thermal evolution of Georges Bank basin
B. Ann Swift, D. S. Sawyer, J. A. Grow, Kim D. Klitgord
1987, American Association of Petroleum Geologists Bulletin (71) 702-718
A geophysical study of Georges Bank basin defines a deep crustal structure that is interpreted in terms of the basin's tectonic and thermal history. Gravity models along three basin cross sections delineate two zones of crustal thinning at the basement hinge zone and oceanic crustal margins. These two zones bound...
DISCRIMINATION OF ALTERED BASALTIC ROCKS IN THE SOUTHWESTERN UNITED STATES BY ANALYSIS OF LANDSAT THEMATIC MAPPER DATA.
Philip A. Davis, Graydon L. Berlin, Pat S. Chavez
1987, Photogrammetric Engineering and Remote Sensing (53) 45-55
Landsat Thematic Mapper image data were analyzed to determine their ability to discriminate red cone basalts from gray flow basalts and sedimentary country rocks for three volcanic fields in the southwestern United States. Analyses of all of the possible three-band combinations of the six nonthermal bands indicate that the combination...
Volatilization, transport and sublimation of metallic and non-metallic elements in high temperature gases at Merapi Volcano, Indonesia
R.B. Symonds, William I. Rose Jr., M.H. Reed, F.E. Lichte, David L. Finnegan
1987, Geochimica et Cosmochimica Acta (51) 2083-2101
Condensates, silica tube sublimates and incrustations were sampled from 500–800°C fumaroles and lava samples were collected at Merapi Volcano, Indonesia in Jan.–Feb., 1984. With respect to the magma, Merapi gases are enriched by factors greater than 105 in Se, Re, Bi and Cd; 104–105 in Au, Br, In, Pb and W; 103–104 in...
Neutron activation determination of iridium, gold, platinum, and silver in geologic samples
Hugh T. Millard Jr.
1987, Journal of Radioanalytical and Nuclear Chemistry Articles (113) 125-132
Low-level methods for the determination of iridium and other noble metals have become increasingly important in recent years due to interest in locating abundance anomalies associated with the Cretaceous and Tertiary (K-T) boundary. Typical iridium anomalies are in the range of 1 to 100 ??g/kg (ppb). Thus methods with detection...
PROTON MICROPROBE ANALYSIS OF TRACE-ELEMENT VARIATIONS IN VITRINITES IN THE SAME AND DIFFERENT COAL BEDS.
J.A. Minkin, E. C. T. Chao, Herma Blank, F.T. Dulong
1987, Scanning Micros (1) 503-513
The PIXE (proton-induced X-ray emission) microprobe can be used for nondestructive, in-situ analyses of areas as small as those analyzed by the electron microprobe, and has a sensitivity of detection as much as two orders of magnitude better than the electron microprobe. Preliminary studies demonstrated that PIXE provides a capability...
Distribution and abundance of tidal marshes along the coast of Maine
H.A. Jacobson, G.L. Jacobson, J. T. Kelley
1987, Estuaries (10) 126-131
Planimetry studies of coastal geology maps prepared by the Maine Geological Survey show that there is more than an order of magnitude more tidal marsh area in the state of Maine than documented in previously published estimates. The highly convoluted coast of Maine, which is approximately 5,970 km long, contains...
The geochemistry of water near a surficial organic-rich uranium deposit, northeastern Washington State, U.S.A.
R. A. Zielinski, J. K. Otton, R. B. Wanty, C. T. Pierson
1987, Chemical Geology (62) 263-289
The chemistry of three stream, three spring and six near-surface waters in the vicinity of a Holocene organic-rich uranium deposit is described, with particular emphasis on the chemistry of U. Results characterize the solution behavior of uranium as U-bearing water interacts with relatively undecomposed, surficial organic matter. Of the measured...
LOUISIANA BARRIER ISLAND EROSION STUDY.
Sallenger Jr., Shea Penland, S. Jeffress Williams, John R. Suter
1987, Conference Paper
During 1986, the U. S. Geological Survey and the Louisiana Geological Survey began a five-year cooperative study focused on the processes which cause erosion of barrier islands. These processes must be understood in order to predict future erosion and to better manage our coastal resources. The study area includes the...
NONHOMOGENEOUS TERMS IN THE UNSTEADY FLOW EQUATIONS: MODELING ASPECTS.
Chintu Lai, Raymond W. Schaffranek, Robert A. Baltzer
1987, Conference Paper
A study is in progress to identify the relative significance, effects, and benefits attributable to the use of one-dimensional, unsteady, open-channel, flow-simulation models employing a variety of nonhomogeneous terms in their equation formulations. Nonhomogeneous terms being analyzed include those representing bed slope, frictional resistance, nonprismatic channel geometry, lateral flow, and...
A model of geomagnetic secular variation for 1980-1983
N.W. Peddie, A.K. Zunde
1987, Physics of the Earth and Planetary Interiors (48) 324-329
We developed an updated model of the secular variation of the main geomagnetic field during 1980 through 1983 based on annual mean values for that interval from 148 worldwide magnetic observatories. The model consists of a series of 80 spherical harmonics, up to and including those of degree and order...
Generation of liquid water on Mars through the melting of a dusty snowpack
G.D. Clow
1987, Icarus (72) 95-127
The possibility that snowmelt could have provided liquid water for valley network formation early in the history of Mars is investigated using an optical-thermal model developed for dusty snowpacks at temperate latitudes. The heating of the postulated snow is assumed to...
On the interpretation of the geomagnetic energy spectrum
E.R. Benton, L.R. Alldredge
1987, Physics of the Earth and Planetary Interiors (48) 265-278
Two recent high-degree magnetic energy spectra, based mostly on MAGSAT data, are compared and found to agree very well out to order and degree n = 15, but the spectrum remains somewhat uncertain for higher degrees. The hypothesis that a primary break in the slope of the spectrum, plotted semi-logarithmically,...
