UNDERWATER MAPPING USING GLORIA AND MIPS.
Pat S. Chavez Jr., Jeffrey A. Anderson, James W. Schoonmaker Jr.
1987, Conference Paper, Oceans Conference Record (IEEE)
Advances in digital image processing of the (GLORIA) Geological Long-Range Induced Asdic) sidescan-sonar image data have made it technically and economically possible to map large areas of the ocean floor including the Exclusive Economic Zone. Software was written to correct both geometric and radiometric distortions that exist in the original...
Evolution of an ophiolitic tectonic melange, Marble Mountains, northern California Klamath Mountains (USA)
M. M. Donato
1987, Geological Society of America Bulletin (98) 448-464
The Marble Mountain terrane of northern California constitutes a metamorphosed ophiolitic tectonic mélange occupying the lowest structural levels of the western Paleozoic and Triassic belt of the Klamath Mountains province. On the basis of lithology and structural position, it probably represents the metamorphosed equivalent of the Rattlesnake Creek terrane. The...
Precambrian geology of the U.S.A.
J. C. Reed Jr.
1987, Episodes (10) 243-247
Although exposures of Precambrian rocks in the USA are widely scattered, recent studies have provided much information about their subsurface distribution and tectonic history. This article reviews the geological development of the Archean craton, orogenic belts and cratonic cover of Proterozoic age, the Midcontinent rift system, and Precambrian rocks caught...
Assessment of models proposed for the 1985 revision of the international geomagnetic reference field
N.W. Peddie, A.K. Zunde
1987, Physics of the Earth and Planetary Interiors (48) 330-337
Geomagnetic measurements from land, marine and aerial surveys conducted in the years 1945-1964 were used to test the 14 models proposed as additions, for that period, to the series of definitive geomagnetic reference field (DGRF) models. Overall, NASA's 'SFAS' models and the BGS (British Geological Survey) models agree best with...
Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence
T. L. Vercoutere, H.T. Mullins, K. McDougall, J.B. Thompson
1987, Journal of Sedimentary Petrology (57) 709-722
Distribution, abundance, and diversity of terrigenous, authigenous, and biogenous material provide evidence of the effect of bottom currents and oxygen minimum zone (OMZ) on continental slope sedimentation offshore central California. Box core samples and bottom photographs collected across the oxygen minimum zone of...
Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State
R. A. Zielinski, R.R. Schumann
1987, Journal of Geochemical Exploration (27) 281-298
Douglas fir trees and associated soils were sampled from the slopes of a small (∼4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger...
Relation of the spectroscopic reflectance of olivine to mineral chemistry and some remote sensing implications
T. V. V. King, W.I. Ridley
1987, Journal of Geophysical Research Solid Earth (92) 11457-11469
Using high-resolution visible and near-infrared diffuse spectral reflectance, we have systematically investigated apparent wavelength shifts as a function of mineral chemistry in the Fe/Mg olivine series from Fo11 to Fo91. The study also shows that trace amounts of nickel can be spectrally detected in the olivine structure. We show that significant...
Global petrologic variations on the moon: A ternary-diagram approach.
P. A. Davis, P. D. Spudis
1987, Journal of Geophysical Research Solid Earth (92) 387-395
A ternary-diagram approach for determination of global petrologic variations on the lunar surface is presented that incorporates valuable improvements in our previous method of using geochemical variation diagrams. This new approach uses a ternary diagram that is subdivided into equally spaced segments along each of its three sides and has...
Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina
C. Erwin Brown
1987, Geoexploration (24) 429-440
Sixty-two Schlumberger electrical soundings were made in the Durham Triassic basin in an effort to determine basin structural geometry, depth of the sedimentary layers, and spatial distribution of individual rock facies. A digital computer program was used to invert the sounding curves of apparent resistivity versus distance to apparent resistivity...
Chemical structural studies of natural lignin by dipolar dephasing solid-state 13C nuclear magnetic resonance
Patrick G. Hatcher
1987, Organic Geochemistry (11) 31-39
Two natural lignins, one from a gymnosperm wood the other from angiosperm wood, were examined by conventional solid-state and dipolar dephasing 13C nuclear magnetic resonance (NMR) techniques. The results obtained from both techniques show that the structure of natural lignins is consistent with models of softwood and hardwood lignin. The dipolar...
Coal deposits of the United States
Nelson W. John
1987, International Journal of Coal Geology (8) 355-365
The coal fields of the Unites States can be divided into six major provinces. The Appalachian and Interior Provinces contain dominantly bituminous coal in strata of Pennsylvanian age. The coal seams are relatively thin and are mined both by surface and...
Economics of the coal industry east of the Mississippi, 1973-1982
S.B. Bhagwat
1987, International Journal of Coal Geology (8) 367-373
Government regulations on health, safety and environment have been poppular blamed for the declining productivity in U.S. coal mines since 1970. The stagnation in the coal industry east of the Mississippi is alleged to have been caused by this declining productivity...
Some effects of quiet geomagnetic field changes upon values used for main field modeling
W.H. Campbell
1987, Physics of the Earth and Planetary Interiors (48) 193-199
The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the...
Playa-lake basins on the Southern High Plains of Texas and New Mexico: Part I. Hydrologic, geomorphic, and geologic evidence for their development
Waite Osterkamp, W.W. Wood
1987, Geological Society of America Bulletin (99) 215-223
Playa-lake basins of the Southern High Plains, Texas and New Mexico, may originate wherever water periodically can collect in a surficial depression. They expand, however, by hydrologic and geomorphic processes including (1) dissolution of lithologic carbonates by infiltrating water; (2) transport downward of fine-grained clastic and organic material by the...
Hydrogeologic reconnaissance of the Beowawe Geysers geothermal area, Nevada
F. H. Olmsted, F. E. Rush
1987, Geothermics (16) 27-46
The Beowawe Geysers in north-central Nevada are the discharge from a hydrothermal-convection system in a region of high heat flow. The site of thermal-fluid upflow (at about 18 kg/s before drilling and well testing) appears to be related to the intersection...
Origin of lead from green glass of Apollo 15426: A search for primitive lunar lead.
M. Tatsumoto, W. R. Premo, D.M. Unruh
1987, Journal of Geophysical Research Solid Earth (92) 361-371
A major obstacle in lunar U-Pb chronology is the elusiveness of the primary Pb isotopic composition and U/Pb ratio and therefore the Pb evolution for the early history of the moon. In an attempt to seek the primitive lunar Pb isotopic composition, green glass from lunar clod 15426,49 was studied...
Sedimentary processes on the northwestern Iberian continental margin viewed by long-range side-scan sonar and seismic data
James V. Gardner, Robert B. Kidd
1987, Journal of Sedimentary Petrology (57) 397-407
The effects of an eastern boundary current in the North Atlantic have been mapped from about 39° north latitude along the Iberian margin to as far north as 43°30 north latitude at the western margin of Galicia Bank. The geostrophic current has produced sediment drifts that are...
The importance of methane and thiosulfate in the metabolism of the bacterial symbionts of two deep-sea mussels
C.R. Fisher, J.J. Childress, R.S. Oremland, R.R. Bidigare
1987, Marine Biology (96) 59-71
Undescribed hydrocarbon-seep mussels were collected from the Louisiana Slope, Gulf of Mexico, during March 1986, and the ultrastructure of their gills was examined and compared to Bathymodiolus thermophilus, a mussel collected from the deep-sea hydrothermal vents on the Gala??pagos Rift in March 1985. These closely related mytilids both contain abundant...
Use of focal mechanisms to determine stress: A control study.
A.J. Michael
1987, Journal of Geophysical Research Solid Earth (92) 357-368
To allow focal mechanisms to be inverted for the stress field requires a different inversion algorithm than for slickenside data because focal mechanisms do not represent fault slip data unless one can decide which nodal plane is the fault plane. If one can decide which nodal plane is the fault...
Geological setting of U.S. fossil fuels.
C.D. Masters, R. F. Mast
1987, Episodes (10) 308-313
The USA has a special position in terms of fossil fuel development. Not only is it one of the most important nations in terms of resources of oil, gas and coal, but it has also been by far the dominant producer and consumer. In this thorough review of the regional...
Maestrichtian benthic foraminifers from Ocean Point, North Slope, Alaska ( USA).
K. McDougall
1987, Journal of Foraminiferal Research (17) 344-366
Previous studies of fauna and flora from Ocean Point, Alaska, have suggested ages ranging from Campanian to early Eocene and that these assemblages are either highly endemic or commonplace. I demonstrate that the moderately abundant benthic foraminifers constitute early Maestrichtian boreal assemblages common to Canada and northern Europe. Paleoenvironmental analysis...
On predicting changes in the geomagnetic field
L.R. Alldredge
1987, Journal of Geophysical Research Solid Earth (92) 6331-6338
The present method of using constant secular variation rates to forecast magnetic components at a given site or to forecast spherical harmonic coefficients is known to be inaccurate. A new predictive method using trend and trigonometric functions fitted to known past values is used to extrapolate for a few years...
Cretaceous gastropods: contrasts between tethys and the temperate provinces
N. F. Sohl
1987, Journal of Paleontology (61) 1085-1111
During the Cretaceous Period, gastropod faunas show considerable differences in their evolution between the Tethyan Realm (tropical) and the Temperate Realms to the north and south. Like Holocene faunas, prosobranch gastropods constitute the dominant part of Cretaceous marine snail faunas. Entomotaeneata and opisthobranchs usually form all of...
Submersible observations along the southern Juan de Fuca Ridge: 1984 Alvin program.
William R. Normark, Janet L. Morton, Stephanie L. Ross
1987, Journal of Geophysical Research B: Solid Earth (92) 11283-11290
In September 1984, the research submersible Alvin provided direct observations of three major hydrothermal vent areas along the southernmost segment of the Juan de Fuca Ridge (JFR). The submersible operations focused on specific volcanologie, structural, and hydrothermal problems that had been identified during the preceding 4 years of photographic, dredging,...
Rocks of the Thirtynine Mile volcanic field as possible sources of uranium for epigenetic deposits in central Colorado, USA.
K. A. Dickinson
1987, Uranium (4) 43-65
The most likely volcanic source rock for uranium in epigenetic deposits of the Tallahassee Creek uranium district and nearby areas is the Wall Mountain Tuff. The widespread occurrence of the Tuff, its high apparent original uranium content, approx 11 ppm, and its apparent loss of uranium from devitrification and other...
