Authigenic vivianite in Potomac River sediments: control by ferric oxy-hydroxides
P.P. Hearn, D.L. Parkhurst, E. Callender
1983, Journal of Sedimentary Petrology (53) 165-177
Sand-size particles of vivianite (Fe 3 (PO 4 ) 2 .8H 2 O) have been identified in surficial sediments of the tidal Potomac River near a major sewage treatment plant. Vivianite is concentrated in a surface layer of coarse-sand dredge spoil, which overlies much finer sediment. Although saturation indices indicate that...
Carbonatite tuffs in the Laetolil Beds of Tanzania and the Kaiserstuhl in Germany
R. L. Hay, J. R. O’Neil
1983, Contributions to Mineralogy and Petrology (82) 403-406
Carbonatite lava and tephra are now well known. The only modern eruptive carbonatites, from Oldoinyo Lengai, Tanzania, are of alkali carbonatite, whereas all of the pre-modern examples are of calcite or dolomite. Chemical and stable isotope analyses were made of separate phases of Pliocene carbonatite tuffs of the Laetolil Beds...
Objective procedures for lineament enhancement and extraction
G. K. Moore, F. A. Waltz
1983, Photogrammetric Engineering and Remote Sensing (49) 641-647
A longterm research goal at EROS Data Center is to develop automated, objective procedures for lineament mapping. In support of this goal, a five-step digital convolution procedure has been used to produce directionally enhanced images, which contain few artifacts and little noise. The main limitation of this procedure is that...
Tin granites of Seward Peninsula, Alaska
T. Hudson, Joseph G. Arth
1983, Geological Society of America Bulletin (94) 768-790
Seven granite plutons, spatially and genetically related to tin metalization, are exposed in a 170-km-long belt across northwestern Seward Peninsula, Alaska. These plutons are cupolas and epizonal composite stocks that consist of several textural varieties of biotite granite, including medium- to coarse-grained seriate...
Simulation of solute transport in a mountain pool-and-riffle stream: A transient storage model
Kenneth E. Bencala, Roy A. Walters
1983, Water Resources Research (19) 718-724
The physical characteristics of mountain streams differ from the uniform and conceptually well- defined open channels for which the analysis of solute transport has been oriented in the past and is now well understood. These physical conditions significantly influence solute transport behavior, as demonstrated by a transient storage model simulation...
Atomic-absorption determination of mercury in geological materials by flame and carbon-rod atomisation after solvent extraction and using co-extracted silver as a matrix modifier
R. F. Sanzolone, T. T. Chao
1983, The Analyst (108) 58-63
Based on modifications and expansion of the original Tindall's solvent extraction flame atomic-absorption procedure, an atomic-absorption spectrophotometric method has been developed for the determination of mercury in geological materials. The sample is digested with nitric and hydrochloric acids in a boiling water-bath. The solution is made ammoniacal and potassium iodide...
Modeling of self-potential anomalies near vertical dikes
D.V. Fitterman
1983, Geophysics (48) 171-180
The self-potential (SP) Green's function for an outcropping vertical dike is derived from solutions for the dc resistivity problem for the same geometry. The Green's functions are numerically integrated over rectangular source regions on the contacts between the dike and the surrounding material to obtain the SP anomaly. The analysis...
Relationship of two lacustrine ostracode species to solute composition and salinity: Implications for paleohydrochemistry ( Limnocythere sappaensis/staplini)
R. M. Forester
1983, Geology (11) 435-438
Nonmarine ostracode species are indicative of the physical and chemical nature of lacustrine environments. Although salinity has traditionally been regarded as one of the more important parameters that affect the occurrence patterns of lacustrine ostracodes, examination of the solute composition and salinities of...
Statistical averaging of marine magnetic anomalies and the aging of oceanic crust
R.J. Blakely
1983, Journal of Geophysical Research Solid Earth (88) 2289-2296
Visual comparison of Mesozoic and Cenozoic magnetic anomalies in the North Pacific suggests that older anomalies contain less short-wavelength information than younger anomalies in this area. To test this observation, magnetic profiles from the North Pacific are examined from crust of three ages: 0–2.1, 29.3–33.1, and 64.9–70.3 m.y, B.P. For...
The use of MAGSAT data to determine secular variation
J.C. Cain, J. Frayser, L. Muth, D. Schmitz
1983, Journal of Geophysical Research Solid Earth (88) 5903-5910
A combined spatial and secular variation model of the geomagnetic field, labeled M061581, is derived from a selection of Magsat data. Secular variation (SV) data computed from linear fits to midnight hourly values from 19 magnetic observatories were also included in the analysis but were seen to have little effect...
Major and trace elements in Mahogany zone oil shale in two cores from the Green River Formation, piceance basin, Colorado
M. L. Tuttle, W.E. Dean, N. L. Parduhn
1983, Conference Paper, Preprints Symposia
The Parachute Creek Member of the lacustrine Green River Formation contains thick sequences of rich oil-shale. The richest sequence and the richest oil-shale bed occurring in the member are called the Mahogany zone and the Mahogany bed, respectively, and were deposited in ancient Lake Uinta. The name "Mahogany" is derived...
Crustal and upper mantle structure of the northern and central Sierra Nevada
B.B. Mavko, G. A. Thompson
1983, Journal of Geophysical Research Solid Earth (88) 5874-5892
Teleseismic data were recorded within the Sierra Nevada to look for lateral variations in the upper mantle. The data were collected at both temporary and permanent stations, and P wave residuals were computed. After correcting the P residual data for crustal and topographic effects, there is still a variation of as much as 0.5-0.6...
The relationship of acquisition systems to automated stereo correlation.
A. P. Colvocoresses
1983, Photogrammetric Engineering and Remote Sensing (49) 539-544
Today a concerted effort is being made to expedite the mapping process through automated correlation of stereo data. Stereo correlation involves the comparison of radiance (brightness) signals or patterns recorded by sensors. Conventionally, two-dimensional area correlation is utilized but this is a rather slow and cumbersome procedure. Digital correlation can...
Paleohydraulic reconstruction of flash- flood peaks from boulder deposits in the Colorado Front Range
J. E. Costa
1983, Geological Society of America Bulletin (94) 986-1004
Nine watersheds in the Colorado Front Range with steep bedrock channels were used to test the accuracy of paleohydraulic reconstruction of large flash floods using boulder deposits. The nine basins consist of eight small ungauged basins ranging in size from 1.6 to 29...
Kinetic analysis of strontium and potassium sorption onto sands and gravels in a natural channel
Kenneth E. Bencala, Alan P. Jackman, Vance C. Kennedy, Ronald J. Avanzino, Gary W. Zellweger
1983, Water Resources Research (19) 725-731
A kinetic, first-order mass transfer model was used to describe the sorption of strontium onto sand- and gravel-sized streambed sediments. Rate parameters, empirically determined for strontium, allowed for the prediction of potassium sorption with moderate success. The model parameters varied significantly with particle size. The sorption data were collected during...
INTERACTIVE NAME PLACEMENT FOR PROVISIONAL MAPS.
Jeffrey L. Goldberg, Thomas C. Miller
1983, Conference Paper, Technical Papers of the American Congress of Surveying and Mapping
Computer generation and placement of map type has been refined into a production mode at Mid-Continent Mapping Center (MCMC) for USGS 1:24,000- and 1:25,000-scale Provisional maps. The map collar program is written in FORTRAN using batch processing that allows the program to work in the background....
VARIATIONS IN MINERAL MATTER CONTENT OF A PEAT DEPOSIT IN MAINE RESTING ON GLACIO-MARINE SEDIMENTS.
Cornelia C. Cameron, Paul Schruben
1983, Conference Paper, Los Alamos National Laboratory (Report) LA
The Great Heath, Washington County, Maine, is an excellent example of a multidomed ombrotrophic peatland resting on a gently undulating surface of glacio-marine sediments and towering above modern streams. A comprehensive study sponsored by the Geological Survey of Maine in cooperation with the U. S. Geological Survey included preparation of...
CHEMICAL STRUCTURES IN COAL: GEOCHEMICAL EVIDENCE FOR THE PRESENCE OF MIXED STRUCTURAL COMPONENTS.
Patrick G. Hatcher, Irving A. Breger, G.E. Maciel, N.M. Szeverenyi
1983, Conference Paper
The purpose of this paper is to summarize work on the chemical structural components of coal, comparing them with their possible plant precursors in modern peat. Solid-state **1**3C nuclear magnetic resonance (NMR), infrared spectroscopy (IR), elemental analysis and, in some cases, individual compound analyses formed the bases for these comparisons....
SUBMICROSCOPIC ( less than 1 mu m) MINERAL CONTENTS OF VITRINITES IN SELECTED BITUMINOUS COAL BEDS.
J.A. Minkin, E. C. T. Chao, C.L. Thompson, M.-V. Wandless, F.T. Dulong, R.R. Larson, S.G. Neuzil
Gooley Ron, editor(s)
1983, Conference Paper, Proceedings, Annual Conference - Microbeam Analysis Society
An important aspect of the petrographic description of coal is the characterization of coal quality, including chemical attributes. For geologic investigations, data on the concentrations, distribution, and modes of occurrence of minor and trace elements provide a basis for reconstructing the probable geochemical environment of the swamp material that was...
Sea ice melting in the marginal ice zone
E.G. Josberger
1983, Journal of Geophysical Research - Oceans (88) 2841-2844
The heat and salt flux boundary conditions together with the freezing curve relationship are a necessary component of any ice-sea water thermodynamic model. A neutral two-layer oceanic planetary boundary layer model that incorporates these boundary conditions gives the following results: The interfacial salinity is within 10% of the far-field salinity...
40Ar/39Ar and U-Th-Pb dating of separated clasts from the Abee E4 chondrite
D.D. Bogard, D.M. Unruh, M. Tatsumoto
1983, Earth and Planetary Science Letters (62) 132-146
Determinations of40Ar/39Ar and U-Th-Pb are reported for three clasts from the Abee (E4) enstatite chondrite, which has been the object of extensive consortium investigations. The clasts give40Ar/39Ar plateau ages and/or maximum ages of 4.5 Gy, whereas two of the clasts give...
Analysis of spurious oscillation modes for the shallow water and Navier-Stokes equations
Roy A. Walters, G. F. Carey
1983, Computers and Fluids (11) 51-68
The origin and nature of spurious oscillation modes that appear in mixed finite element methods are examined. In particular, the shallow water equations are considered and a modal analysis for the one-dimensional problem is developed. From the resulting dispersion relations we find that the spurious modes in elevation are associated...
DETERMINATION OF MODE OF OCCURRENCE OF TRACE ELEMENTS IN THE UPPER FREEPORT COAL BED USING SIZE AND DENSITY SEPARATION PROCEDURES.
C.A. Palmer, R.H. Filby
1983, Conference Paper
A procedure has been developed using low temperature ashing, followed by size and sink-float separation of the ash, X-ray diffraction analysis, and instrumental neutron activation analysis to give both qualitative and quantitative information for major, minor and trace minerals and their associated trace elements in coal....
Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion
John D. Bredehoeft, Richard A. Young
1983, Water Resources Research (19) 1111-1121
In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what...
Scoresum - A technique for displaying and evaluating multi-element geochemical information, with examples of its use in regional mineral assessment programs
M.A. Chaffee
1983, Journal of Geochemical Exploration (19) 361-381
A technique called SCORESUM was developed to display a maximum of multi-element geochemical information on a minimum number of maps for mineral assessment purposes. The technique can be done manually for a small analytical data set or can be done with a computer for a large data set. SCORESUM...
