Isotopic variation in the Tuolumne Intrusive Suite, central Sierra Nevada, California
R. W. Kistler, B. W. Chappell, D. L. Peck, P. C. Bateman
1986, Contributions to Mineralogy and Petrology (94) 205-220
Granitoid rocks of the compositionally zoned Late Cretaceous Toulumne Intrusive Suite in the central Sierra Nevada, California, have initial87Sr/86Sr values (Sri) and143Nd/144Nd values (Ndi) that vary from 0.7057 to 0.7067 and from 0.51239 to 0.51211 respectively. The observed variation of both Sri and Ndi and of chemical composition in rocks...
Suspended sediment transport in an estuarine tidal channel within San Francisco Bay, California
R.W. Sternberg, D.A. Cacchione, D.E. Drake, K. Kranck
1986, Marine Geology (71) 237-258
A recently developed instrumentation system has been used to monitor simultaneously flow conditions and suspended sediment distribution in the bottom boundary layer of a tidal channel within San Francisco Bay, California. Measurements were made every 15 min over six successive flood and ebb tidal cycles. They included mean velocity profiles...
Fumarole emissions at Mount St. Helens volcano, June 1980 to October 1981: Degassing of a magma-hydrothermal system
T.M. Gerlach, T. J. Casadevall
1986, Journal of Volcanology and Geothermal Research (28) 141-160
This study is an investigation of the chemical changes in the Mount St. Helens fumarole gases up to October 1981, the sources of the fumarole gases, and the stability of gas species in the shallow magma system. These problems are investigated by calculations of element compositions, thermodynamic equilibria, and magmatic...
Isotopic constraints on the origin of the Atlantis II, Suakin and Valdivia brines, Red Sea
R.A. Zierenberg, Wayne C. Shanks III
1986, Geochimica et Cosmochimica Acta (50) 2205-2214
The origin of three Red Sea submarine brine pools was investigated by analysis of the S and O isotope ratios of dissolved sulfate and Sr isotope ratios of dissolved Sr in the brines. Sulfur and O isotope ratios of sulfate and Sr isotope ratios of evaporitic source rocks for the...
Manganese biogeochemistry in a small Adirondack forested lake watershed
James B. Shanley
1986, Water Resources Research (22) 1647-1656
In September and October 1981, manganese (Mn) concentrations and pH were intensively monitored in a small forested lake watershed in the west-central Adirondack Mountains, New York, during two large acidic storms (each ∼5 cm rainfall, pH 4.61 and 4.15). The data were evaluated to identify biogeochemical pathways of Mn and to assess...
Optical reflection from planetary surfaces as an operator-eigenvalue problem
R.L. Wildey
1986, Earth, Moon and Planets (36) 103-116
The understanding of quantum mechanical phenomena has come to rely heavily on theory framed in terms of operators and their eigenvalue equations. This paper investigates the utility of that technique as related to the reciprocity principle in diffuse reflection. The reciprocity operator is shown to be unitary and Hermitian; hence,...
Repetitive digital NOAA-AVHRR data for Alaskan engineering and scientific applications
William M. Christie, Robert J. Pawlowski, Michael D. Fleming
1986, Conference Paper, Technical Papers of the American Society of Photogrammetry, Fall Technical Meeting
Selected digitally enhanced NOAA - Advanced Very High Resolution Radiometer (AVHRR) images taken by the NOAA 6, 7, 8 and 9 Polar Orbiting Satellites demonstrate the capability and application of repetitive low-resolution satellite data to Alaska's engineering and science community. Selected cloud-free visible and thermal infrared images are enhanced to...
Improved method for correlating late Pleistocene/Holocene records from the Bering Sea: Application of a biosiliceous/geochemical stratigraphy
J. J. Morley, Stephen Robinson
1986, Deep Sea Research Part A, Oceanographic Research Papers (33) 1203-1211
The combination of high-resolution siliceous biostratigraphy and radiocarbon dating provides a mechanism for detailed assessment of the depositional history in late Pleistocene sediments from the Bering Sea where average accumulation rates are uncharacteristically high compared to rates calculated for most other ocean basins. Vital to the development of this stratigraphy...
Partition coefficients of Hf, Zr, and REE between zircon, apatite, and liquid
H. Fujimaki
1986, Contributions to Mineralogy and Petrology (94) 42-45
Concentration ratios of Hf, Zr, and REE between zircon, apatite, and liquid were determined for three igneous compositions: two andesites and a diorite. The concentration ratios of these elements between zircon and corresponding liquid can approximate the partition coefficient. Although the concentration ratios between apatite and andesite groundmass can be...
Lithic breccia and ignimbrite erupted during the collapse of Crater Lake Caldera, Oregon
T. H. Druitt, C. R. Bacon
1986, Journal of Volcanology and Geothermal Research (29) 1-32
The climactic eruption of Mount Mazama (6845 y.B.P.) vented a total of ∼50 km3 of compositionally zoned rhyodacitic to basaltic magma from: (a) a single vent as a Plinian pumice fall deposit and the overlying Wineglass Welded Tuff, and (b) ring vents as ignimbrite and coignimbrite lithic breccia accompanying the collapse...
Tectonic significance of precambrian apatite fission-track ages from the midcontinent United States
K.D. Crowley, C. W. Naeser, C.A. Babel
1986, Earth and Planetary Science Letters (79) 329-336
Apparent apatite fission-track ages from drill core penetrating basement on the flank of the Transcontinental Arch in northwestern Iowa range from 934 ± 86 to 641 ± 90 Ma. These ages, the oldest reported in North America, record at least two...
Shuttle imaging radar: Physical controls on signal penetration and subsurface scattenng in the Eastern Sahara
Gerald G. Schaber, John F. McCauley, Carol S. Breed, Gary R. Olhoeft
1986, IEEE Transactions on Geoscience and Remote Sensing (GE-24) 603-623
SIR-A signal penetration and subsurface backscatter within the upper meter or so of the sediment blanket in the Eastern Sahara of southern Egypt and northern Sudan are enhanced both by radar sensor parameters and by the physical and chemical characteristics of eolian and alluvial materials. Interpretation of SIR-A images by...
Late-Wisconsin paleohydrology of the West-Central Amargosa Desert, Nevada, U.S.A.
H.C. Claassen
1986, Chemical Geology: Isotope Geoscience Section (58) 311-323
Studies of isotopes in groundwater using 14C, 2H (deuterium) and 18O have provided significant insight into the paleoclimate of middle and late Wisconsin age in a typical arid environment of southern Nevada, the west-central Amargosa Desert. Evidence indicates that recharge probably was through infiltration of...
Uranium series disequilibrium in a young surficial uranium deposit, northeastern Washington, U.S.A.
R. A. Zielinski, C. A. Bush, J.N. Rosholt
1986, Applied Geochemistry (1) 503-511
A recently discovered ore-grade accumulation of U in organic-rich sediments of late Quaternary age provides an opportunity for studying the early association of U, U-daughters, and organic matter in a natural setting. The U occurs in valley-fill sediments of peat, peaty clay, silt, and sand along the north fork of...
The heat capacity of a natural monticellite and phase equilibria in the system CaO-MgO-SiO2-CO2
Z.D. Sharp, E.J. Essene, Lawrence M. Anovitz, G.W. Metz, E.F. Westrum Jr., B. S. Hemingway, J.W. Valley
1986, Geochimica et Cosmochimica Acta (50) 1475-1484
The heat capacity of a natural monticellite (Ca1.00Mg.09Fe.91Mn.01Si0.99O3.99) measured between 9.6 and 343 K using intermittent-heating, adiabatic calorimetry yields Cp0(298) and S2980 of 123.64 ± 0.18 and 109.44 ± 0.16 J · mol−1K−1 respectively. Extrapolation of this entropy value to end-member monticellite results in an S0298 = 108.1 ±...
Obstacles facing the venus radar mapper - The implications of gestalt formation in stereo-radargrammetry
R.L. Wildey
1986, Earth, Moon and Planets (35) 47-54
The question of adapting to radar images the existing hardware that form topographic maps through stereo-photogrammetric models, is examined in principle. Such hardware utilizes a human/ computer hybrid. Although the problem of brightness differentials between corresponding landmarks can be dealt with pseudo-photoclinometrically, the main problem is whether the perspective in...
Estimating monthly streamflow values by cokriging
A.R. Solow, S.M. Gorelick
1986, Mathematical Geology (18) 785-809
Cokriging is applied to estimation of missing monthly streamflow values in three records from gaging stations in west central Virginia. Missing values are estimated from optimal consideration of the pattern of auto- and cross-correlation among standardized residual log-flow records. Investigation of the sensitivity of estimation to data configuration showed that...
Mass storage estimates for the digital mapping era.
D.L. Light
1986, Photogrammetric Engineering and Remote Sensing (52) 419-425
Proponents of the digital era recognize that a break-through in mass storage technology may be required to attain a reasonable degree of computerization of the cartographic mapping and data management process. This paper provides the rationale for estimating that about 1014 bits of digital mass storage are needed for developing...
A numerical investigation of head waves and leaky modes in fluid- filled boreholes
Frederick L. Paillet, C.H. Cheng
1986, Geophysics (51) 1438-1449
Although synthetic borehole seismograms can be computed for a wide range of borehole conditions, the physical nature of shear and compressional head waves in fluid-filled boreholes is poorly understood. This paper presents a series of numerical experiments designed to explain the physical mechanisms controlling head-wave propagation in boreholes. These calculations...
Ground-water recharge and its effects on nitrate concentration beneath a manured field site in Pennsylvania
J. M. Gerhart
1986, Groundwater (24) 483-489
Ground-water recharge to a shallow, unconfined, fractured dolomite aquifer underlying agricultural land in Lancaster County, Pennyslvania occurs by two mechanisms. Direct recharge occurs through pathways such as near-surface bedrock fractures and sinkholes, and affects dissolved nitrate concentration of ground water within two to three days; its effects last only about...
Color images of Kansas subsurface geology from well logs
D.R. Collins, J.H. Doveton
1986, Computers & Geosciences (12) 519-526
Modern wireline log combinations give highly diagnostic information that goes beyond the basic shale content, pore volume, and fluid saturation of older logs. Pattern recognition of geology from logs is made conventionally through either the examination of log overlays or log crossplots. Both methods can be combined through the use...
A spherical electron-channelling pattern map for use in quartz petrofabric analysis
G.E. Lloyd, C.C. Ferguson
1986, Journal of Structural Geology (8) 517-526
Electron channelling patterns (ECP's) are formed in the scanning electron microscope (SEM) by the interaction between the incident electrons and the lattice of crystalline specimens. The patterns are unique for a particular crystallographic orientation and are therefore of considerable potential in...
Field observations of bed shear stress and sediment resuspension on continental shelves, Alaska and California
D.E. Drake, D.A. Cacchione
1986, Continental Shelf Research (6) 415-429
Bed shear stress was estimated using wave and current measurements obtained with the GEOPROBE bottom-tripod system during resuspension events in Norton Sound, Alaska, and on the northern California shelf. The boundary-layer model of Grant and Madsen (1979, Journal of Geophysical Research, 84, 1797-1808) was used to compute the bed shear...
Metamorphosed melange terrane in the eastern Piedmont of North Carolina
J. Wright Horton Jr., D.E. Blake, A.S. Wylie Jr., E.F. Stoddard
1986, Geology (14) 551-553
The Falls Lake melange crops out in the eastern Piedmont of North Carolina between the Carolina slate belt and the Raleigh belt. The melange is composed of mafic and ultramafic blocks and pods of diverse shapes and sizes, dispersed without apparent stratigraphic continuity,...
Design and cost analysis of rapid aquifer restoration systems using flow simulation and quadratic programming
L.J. Lefkoff, S.M. Gorelick
1986, Groundwater (24) 777-790
Detailed two-dimensional flow simulation of a complex ground-water system is combined with quadratic and linear programming to evaluate design alternatives for rapid aquifer restoration. The design model ensures that a contaminant plume is removed and treated within four years at the least possible cost. Rapid restoration is accomplished by maintaining...
