Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: A quick, efficient process of igneous differentiation
Rosalind Tuthill Helz, H. Kirschenbaum, J.W. Marinenko
1989, Geological Society of America Bulletin (101) 578-594
Kilauea Iki lava lake, formed in 1959, is a large pond of picritic basalt (average MgO content = 15.34% by weight), which has cooled and crystallized as a small, self-roofed magma chamber. Repeated drilling of the upper crust of the lake, down to its molten core, and more recent (1981)...
Rocky Mountain Tertiary coal-basin models and their applicability to some world basins
R. M. Flores
1989, International Journal of Coal Geology (12) 767-798
Tertiary intermontane basins in the Rocky Mountain region of the United States contain large amounts of coal resources. The first major type of Tertiary coal basin is closed and lake-dominated, either mud-rich (e.g., North Park Basin, Colorado) or mud plus carbonate...
Nearshore bars and the break-point hypothesis
A. H. Sallenger Jr., Peter A. Howd
1989, Coastal Engineering (12) 301-313
The set of hypotheses calling for bar formation at the break point was tested with field data. During two different experiments, waves were measured across the surf zone coincident with the development of a nearshore bar. We use a criterion, based on the wave height to depth ratio, to determine...
Predictors of the peak width for networks with exponential links
B.M. Troutman, M.R. Karlinger
1989, Stochastic Hydrology and Hydraulics (3) 1-16
We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function...
A high-density remote reference magnetic variation profile in the Pacific northwest of North America
J.F. Hermance, S. Lusi, W. Slocum, G.A. Neumann, A.W. Green Jr.
1989, Physics of the Earth and Planetary Interiors (53) 305-319
During the summer of 1985, as part of the EMSLAB Project, Brown University conducted a detailed magnetic variation study of the Oregon Coast Range and Cascades volcanic system along an E-W profile in central Oregon. Comprised of a sequence of 75 remote reference magnetic variation (MV) stations spaced 3-4 km...
Use of on-site high performance liquid chromatography to evaluate the magnitude and extent of organic contaminants in aquifers
D.F. Goerlitz, B.J. Franks
1989, Ground Water Monitoring Review (9) 122-129
Appraisal of ground water contaminated by organic substances raises problems of difficult sample collection and timely chemical analysis. High-performance liquid chromatography was evaluated for on-site determination of specific organic contaminants in ground water samples and was used at three study sites. Organic solutes were determined directly in water samples, with...
Oxygen isotope exchange kinetics of mineral pairs in closed and open systems: Applications to problems of hydrothermal alteration of igneous rocks and Precambrian iron formations
R. T. Gregory, R.E. Criss, H.P. Taylor Jr.
1989, Chemical Geology (75) 1-42
The systematics of stable-isotope exchange between minerals and fluids are examined in the context of modal mineralogical variations and mass-balance considerations, both in closed and in open systems. On mineral-pair ??18O plots, samples from terranes that have exchanged with large amounts of fluid typically map out steep positively-sloped non-equilibrium arrays....
Seismic reflection images of the crust of the northern part of the Chugach terrane, Alaska: Results of a survey for the Trans-Alaska Crustal Transect (TACT)
M. A. Fisher, T.M. Brocher, W. J. Nokleberg, George Plafker, G.L. Smith
1989, Journal of Geophysical Research Solid Earth (94) 4424-4440
Deep crustal seismic reflection data show strong reflections from the middle and lower crust of the convergent continental margin near the eastern end of the Aleutian trench. These data were collected across the Border Ranges fault system, a major suture zone that separates the Peninsular and Chugach tectonostratigraphic terranes. The...
A semiquantitative X-ray diffraction method to determine mineral composition in stream sediments with similar mineralogy
Daniel M. Webster
1989, Environmental Technology Letters (10) 833-844
A semiquantitative X‐ray diffraction procedure has been developed that can be used to acquire reproducible mineralogic data from geographically unrelated stream‐sediment samples having similar mineralogy. Weight percentages for quartz, total‐feldspar, and total‐clay can be determined by direct comparison of intensities with standard‐mineral mixtures of known weight percent. Matrix effects and...
High-resolution seismic-reflection interpretations of some sediment deposits, Antarctic continental margin: Focus on the western Ross Sea
Herman A. Karl
1989, Marine Geology (85) 205-223
High-resolution seismic-reflection data have been used to a varying degree by geoscientists to interpret the history of marine sediment accumulations around Antarctica. Reconnaissance analysis of 1-, 3.5-, and 12-kHz data collected by the U.S. Geological Survey in the western Ross Sea...
Heat capacities and entropies from 8 to 1000 K of langbeinite (K2Mg2(SO4)3), anhydrite (CaSO4) and of gypsum (CaSO4·2H2O)
Richard A. Robie, Susan Russell-Robinson, Bruce S. Hemingway
1989, Thermochimica Acta (139) 67-81
Heat capacities of K2Mg2(SO4)3 (langbeinite) and CaSO4 (anhydrite) were measured from approximately 8 to 1000 K by combined adiabatic shield calorimetry (8-365 K) and differential scanning calorimetry (350-1000 K). Heat capacities were also measured on natural crystals of gypsum (CaSO4 · 2H2O) between 8.1 and 323.5 K. The molar entropies at 298.15...
Marine origin of pyritic sulfur in the Lower Bakerstown coal bed, Castleman coal field, Maryland (U.S.A.)
P.C. Lyons, J. F. Whelan, F.T. Dulong
1989, International Journal of Coal Geology (12) 329-348
The amount, kind, distribution, and genesis of pyrite in the Lower Bakerstown coal bed in a 150 × 15 m area of the Bettinger mine, Castleman coal field, Maryland, were studied by various analytical techniques. The mined coal, which had a...
Recharge of the early atmosphere of Mars by impact-induced release of CO2
Michael H. Carr
1989, Icarus (79) 311-327
Channels on the Martian surface suggest that Mars had an early, relatively thick atmosphere. If the atmosphere was thick enough for water to be stable at the surface, CO2 in the atmosphere would have been fixed as carbonates on a relatively short time scale, previously estimated to be 1 bar...
Simulation of precipitation by weather-type analysis
G. J. McCabe Jr., L.E. Hay, L.S. Kalkstein, M. A. Ayers, D.M. Wolock
1989, Conference Paper
A new approach that uses weather-type analysis as a basis for stochastic precipitation modeling was developed and tested for Philadelphia, Pennsylvania. The weather types permit the identification of weather conditions associated with varying frequencies, intensities, and amounts of precipitation. Weather-type frequencies were used to stochastically simulate precipitation for Philadelphia and...
Optimal-adaptive filters for modelling spectral shape, site amplification, and source scaling
Erdal Safak
1989, Soil Dynamics and Earthquake Engineering (8) 75-95
Optimal filtering techniques have been used successfully in various areas in science and engineering. They are based on statistical properties of the signal and the noise, and stochastic approximation theory. In addition to filtering, optimal filters can also be used for smoothing, prediction, and system identification. This paper introduces some...
Remarkable isotopic and trace element trends in potassic through sodic Cretaceous plutons of the Yukon-Koyukuk Basin, Alaska, and the nature of the lithosphere beneath the Koyukuk terrane
Joseph G. Arth, Robert E. Criss, Clara C. Zmuda, Nora K. Foley, W. W. Patton Jr., T. P. Miller
1989, Journal of Geophysical Research B: Solid Earth (94) 15957-15968
During the period from 110 to 80 m.y. ago, a 450-km-long magmatic belt was active along the northern margin of Yukon-Koyukuk basin and on eastern Seward Peninsula. The plutons intruded Upper Jurassic(?) and Lower Cretaceous volcanic arc rocks and Cretaceous sedimentary rocks in Yukon-Koyukuk basin and Proterozoic and lower Paleozoic...
Geohydrology of the Laura fresh-water lens, Majuro atoll: A hydrogeochemical approach
S. S. Anthony, F.L. Peterson, F.T. MacKenzie, S. N. Hamlin
1989, Geological Society of America Bulletin (101) 1066-1075
In small limestone islands, the depositional history and subsequent chemical interactions between ground water and the aquifer host rock play critical roles in the occurrence, movement, and chemical quality of ground water. The hydrogeochemistry of the Laura fresh-water lens, Majuro atoll, Marshall Islands, is an example of these relations.Laura is...
Transport of microspheres and indigenous bacteria through a sandy aquifer: Results of natural- and forced-gradient tracer experiments
R.W. Harvey, L.H. George, R. L. Smith, D.R. LeBlanc
1989, Environmental Science & Technology (23) 51-56
Transport of indigenous bacteria through sandy aquifer sediments was investigated in forced- and natural-gradient tracer teste. A diverse population of bacteria was collected and concentrated from groundwater at the site, stained with a DNA-specific fluorochrome, and injected back into the aquifer. Included with the injectate were a conservative tracer (Br-...
Active faulting and deformation of the Coalinga anticline as interpreted from three-dimensional velocity structure and seismicity
D. Eberhart-Phillips
1989, Journal of Geophysical Research Solid Earth (94) 15565-15586
This work gives a clear picture of the geometry of aftershock seismicity in a large thrust earthquake. Interpretation of hypocenters and fault plane solutions, from the 1983 Coalinga, Coast Range California, earthquake sequence, in combination with the three-dimensional velocity structure shows that the active faulting beneath the fold primarily consists...
Spectral analysis and filtering techniques in digital spatial data processing
Jeng-Jong Pan
1989, Photogrammetric Engineering and Remote Sensing (55) 1203-1207
A filter toolbox has been developed at the EROS Data Center, US Geological Survey, for retrieving or removing specified frequency information from two-dimensional digital spatial data. This filter toolbox provides capabilities to compute the power spectrum of a given data and to design various filters in the frequency domain. Three...
Geochemical variations in a core of hydrogeologic units near Freehold, New Jersey
A. A. Pucci Jr., J. P. Owens
1989, Groundwater (27) 802-812
Solutes were determined for 26 pore-water samples extracted from Tertiary and Cretaceous core material from a 1,320-foot-deep test borehole at Freehold, New Jersey. The cored materials are sediments that form a multilayered aquifer system of seven aquifers and eight confining units in the New Jersey...
The evolution of thermal structure and water chemistry in Lake Nyos
G.W. Kling, M. L. Tuttle, William C. Evans
1989, Journal of Volcanology and Geothermal Research (39) 151-165
We collected a time series of physical and chemical data to gain a better understanding of the dynamics of Lake Nyos. Measurements of water and gas chemistry, and temperature made during January, March, and May 1987 are compared to data taken in September 1986 just after the initial CO2 gas...
Re-Os, Rb-Sr, and O isotopic systematics of the Archean Kolar schist belt, Karnataka, India
R.J. Walker, S.B. Shirey, G. N. Hanson, V. Rajamani, M.F. Horan
1989, Geochimica et Cosmochimica Acta (53) 3005-3013
The Re-Os, Rb-Sr, and O isotopic compositions of mafic and ultramafic amphibolites, gold ores, and granitic gneisses of the circa 2700 Ma Kolar schist belt reveal at least two episodes of post-magmatic alteration that affected these systems. The Re-Os isotopic systematics of many of the rocks of the belt indicate...
State of stress and modern deformation of the northern Basin and Range Province
M.L. Zoback
1989, Journal of Geophysical Research Solid Earth (94) 7105-7128
Constraints on the current stress regime of the actively extending northern Basin and Range province are provided by deformation data (focal mechanisms and fault slip studies), hydraulic fracturing in situ stress measurements, borehole elongation (“breakouts”) analyses, and alignment of young volcanic vents. The integrated data indicate significant variations both in...
Implementation of a hydrodynamic model for the upper Potomac Estuary
Raymond W. Schaffranek, Robert A. Baltzer
1989, Conference Paper
A vertically integrated, two-dimensional hydrodynamic/transport model has been implemented for the upper extent of the Potomac Estuary between Indian Head and Morgantown, Md. The model computes water-surface elevations, flow velocities, and time-varying constituent concentrations by numerically integrating finite-difference forms of the equations of mass and momentum conservation in conjunction with...
