Comparison of marine gas hydrates in sediments of an active and passive continental margin
K.A. Kvenvolden
1985, Marine and Petroleum Geology (2) 65-71
Two sites of the Deep Sea Drilling Project in contrasting geologic settings provide a basis for comparison of the geochemical conditions associated with marine gas hydrates in continental margin sediments. Site 533 is located at 3191 m water depth on a spit-like extension of the continental rise on a passive...
Cleavage strain in the Variscan fold belt, County Cork, Ireland, estimated from stretched arsenopyrite rosettes
M. Ford, C.C. Ferguson
1985, Journal of Structural Geology (7) 217-223
In south-west Ireland, hydrothermally formed arsenopyrite crystals in a Devonian mudstone have responded to Variscan deformation by brittle extension fracture and fragment separation. The interfragment gaps and terminal extension zones of each crystal are infilled with fibrous quartz. Stretches within the...
Genesis and evolution of water in a two-mica pluton: A hydrogen isotope study
R. H. Brigham, J. R. O’Neil
1985, Chemical Geology (49) 159-177
Measurements were made of the hydrogen isotope composition of 74 samples of muscovite, biotite, vein quartz and whole rocks from the Papoose Flat pluton, eastern California, U.S.A., and adjacent metamorphic and sedimentary rocks in order to elucidate the genesis and evolution of water and hydrous minerals in a two-mica granodiorite....
A geophysical and geological study of Laguna de Ayarza, a Guatemalan caldera lake
L.J. Poppe, C. K. Paull, C. G. Newhall, J.P. Bradbury, J. Ziagos
1985, Journal of Volcanology and Geothermal Research (25) 125-144
Geologic and geophysical data from Laguna de Ayarza, a figure-8-shaped doublecaldera lake in the Guatemalan highlands, show no evidence of postcaldera eruptive tectonic activity. The bathymetry of the lake has evolved as a result of sedimentary infilling. The western caldera is steep-sided and contains a large flat-floored central basin 240...
THREE-COMPONENT BOREHOLE MAGNETOMETER PROBE FOR MINERAL INVESTIGATIONS AND GEOLOGIC RESEARCH.
James H. Scott, Gary G. Olson
1985, Conference Paper, Transactions of the SPWLA Annual Logging Symposium (Society of Professional Well Log Analysts)
A small-diameter three-component fluxgate magnetometer probe with gyroscopic and inclinometer orientation has been developed to meet U. S. Geological Survey design and performance specifications for measurement of the direction and intensity of the Earth's magnetic field in vertical and inclined boreholes. The orthogonal fluxgate magnetometer elements have a measurement resolution...
Summary of data on the age of the Orca Group, Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1984
George Plafker, Gerta Keller, Steven W. Nelson, Julie A. Dumoulin, Marti L. Miller
1985, Circular 967
The Orca Group is a widespread, thick, complexly deformed accretionary sequence of flysch and tholeiitic basalt in the Prince William Sound area (Winkler, 1976; Winkler and Plafker, 1981) (fig. 49). Despite a number of extensive field studies of the Orca Group, reliable data on the age of the unit have...
Carboniferous paleogeographic, phytogeographic, and paleoclimatic reconstructions
D.B. Rowley, A. Raymond, Judith T. Parrish, A.L. Lottes, C.R. Scotese, A.M. Ziegler
1985, International Journal of Coal Geology (5) 7-42
Two revised paleogeographic reconstructions of the Visean and Westphalian C-D stages are presented based on recent paleomagnetic, phytogeographic, stratigraphic, and tectonic data. These data change the positions of some continental blocks, and allow the definition of several new ones. The most...
Subdivision of thick sedimentary units into layers for simulation of groundwater flow
J. S. Weiss, A. K. Williamson
1985, Groundwater (23) 767-774
Subdividing thick sedimentary units into model layers based solely on stratigraphy can lead to serious violation of groundwater flow modeling restraints and produce erroneous results. Borehole geophysical data can be used to suggest relative permeabilities and delineate model layers that are more likely to have uniform hydraulic properties than layers...
Federal coal resource occurrence and coal development potential maps of the Pinehaven 7 1/2-minute quadrangle, McKinley County, New Mexico
Berge Exploration Inc.
1985, Open-File Report 80-40
No abstract available....
Degradation of carbohydrates and lignins in buried woods
J. I. Hedges, G.L. Cowie, J.R. Ertel, Barbour R. James, Patrick G. Hatcher
1985, Geochimica et Cosmochimica Acta (49) 701-711
Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from...
Correlation of ash-flow tuffs
W. Hildreth, G. Mahood
1985, Geological Society of America Bulletin (96) 968-974
Discrimination and correlation of ash-flow sheets is important in structurally complex, long-lived volcanic fields where such sheets provide the best keys to the regional stratigraphic framework. Three-dimensional complexities resulting from pulsatory eruptions, sectorial emplacement, mechanical sorting during outflow, thermal and compositional zoning of...
Magadi-type chert, indicator of a lacustrine environment in the Middle Eocene McBean formation, South Carolina.
B. B. Houser
1985, Southeastern Geology (25) 185-197
Magadi-type chert (chert derived from magadiite) occurs in the basal part of the formation at three localities in Orangeburg and Calhoun Counties. These occurrences imply that the basal part of the McBean formation was deposited here in an alkaline lake with a high silica content. Formation and filling of the...
U-Pb isochron age and Pb isotope systematics of the Golden Fleece vein; implications for the relationship of mineralization to the Lake City caldera, western San Juan Mountains, Colorado
K. Hon, K.R. Ludwig, K. R. Simmons, J. F. Slack, R. I. Grauch
1985, Economic Geology (80) 410-417
A U-Pb isochron age of 27.5 + or - 0.5 m.y. has been determined for the Golden Fleece vein, southwestern Colorado, which contains an assemblage of pitchblende and gold-silver tellurides unique within the Lake City area. Initial Pb isotope ratios of ore samples from the vein ( 206 Pb/ 204 Pb = 19.08-19.58; 207 Pb/ 204 Pb =...
Comparison of digestion methods for total elemental analysis of peat and separation of its organic and inorganic components
C. S.E. Papp, T. F. Harms
1985, The Analyst (110) 237-242
In order to find the most efficient digestion method for the total elemental recovery in peat, ten samples were subjected to different techniques and analysed for Ca, Mg, Fe, AI, Na, K, Mn, P, Zn, Cu, Li, Cd, Co, Ni, Pb and Si using atomic-absorption spectrophotometry. The most satisfactory procedures...
Geology of the Brick Flat massive sulfide body, Iron Mountain cluster, West Shasta district, California
J. P. Albers
1985, Economic Geology (80) 2092-2099
The Brick Flat massive sulfide body is one of a group of 8 individual bodies that constitute the Iron Mountain cluster in the S part of the West Shasta district. Before they were separated by postmineral faulting, 5 of the 8 sulfide bodies formed a single large deposit about 1375...
Comparison of methods for estimating ground-water pumpage for irrigation
Steven A. Frenzel
1985, Groundwater (23) 220-226
Ground-water pumpage for irrigation was measured at 32 sites on the eastern Snake River Plain in southern Idaho during 1983. Pumpage at these sites also was estimated by three commonly used methods, and pumpage estimates were compared to measured values to determine the accuracy...
Justification for a reduction in the crest-stage gage program in Louisiana
Richard A. Herbert, Darrell D. Carlson, Gregg J. Wiche
1985, Water Resources Bulletin (21) 953-965
The crest-stage gage program in Louisiana was evaluated to determine if the data were adequate for use in developing regional flood-frequency equations and to determine if any crest-stage gage stations could be discontinued. An abundance of data at many crest-stage gage stations and a lack of data for urban areas...
Assessment of nasal marker materials and designs used on dabbling ducks
J. T. Lokemoen, D.E. Sharp
1985, Wildlife Society Bulletin (13) 53-56
Abstract has not been submitted...
Antigen uptake by gill cells of Atlantic salmon given bath immunizations with Yersinia ruckeri bacterins
D. P. Anderson, A.G. Zapata, M. Wisniewski
1985, American Zoologist (25) 75A-75A
No abstract available....
A quantitative analysis of the Lassen hydrothermal system, north central California
S. E. Ingebritsen, M.L. Sorey
1985, Water Resources Research (21) 853-868
Our conceptual model of the Lassen system is termed a liquid-dominated hydrothermal system with a parasitic vapor-dominated zone. The essential feature of this model is that steam and steam-heated discharge at relatively high altitudes in Lassen Volcanic National Park (LVNP) and liquid discharge with high chloride concentrations at relatively low...
Electronic spectra of Fe3+ oxides and oxide hydroxides in the near IR to near UV.
David M. Sherman, T.D. Waite
1985, American Mineralogist (70) 1262-1269
Optical absorption and diffuse reflectance spectra of several Fe2O3 and FeOOH polymorphs (hematite, maghemite, goethite, lepidocrocite) in the near-IR to near-UV spectral regions (2000-200 nm) are presented. The spectra consist primarily of Fe3+ ligand field and ligand-to-metal charge-transfer transitions.-J.A.Z....
Time scales of change in the San Francisco Bay benthos
F.H. Nichols, J.K. Thompson
1985, Hydrobiologia (129) 121-138
Results from multi-year investigations in the San Francisco Bay estuary show that large abundance fluctuations within benthic macroinvertebrate populations reflect both (1) within-year periodicity of reproduction, recruitment, and mortality that is not necessarily coincident with seasonal changes of the environment (e.g., the annual temperature cycle), and (2) aperiodic density changes...
Mechanistic roles of soil humus and minerals in the sorption of nonionic organic compounds from aqueous and organic solutions
C. T. Chiou, T.D. Shoup, P.E. Porter
1985, Organic Geochemistry (8) 9-14
Mechanistic roles of soil humus and soil minerals and their contributions to soil sorption of nonionic organic compounds from aqueous and organic solutions are illustrated. Parathion and lindane are used as model solutes on two soils that differ greatly in their humic and mineral contents. In aqueous systems, observed sorptive...
Analysis of low levels of rare earths by radiochemical neutron activation analysis
G.A. Wandless, J. W. Morgan
1985, Journal of Radioanalytical and Nuclear Chemistry Articles (92) 273-282
A procedure for the radiochemical neutron-activation analysis for the rare earth elements (REE) involves the separation of the REE as a group by rapid ion-exchange methods and determination of yields by reactivation or by energy dispersive X-ray fluorescence (EDXRF) spectrometry. The U. S. Geological Survey (USGS) standard rocks, BCR-1 and...
Latest Mississippian (Namurian A) nonmarine ostracodes from West Virginia and Virginia
I. G. Sohn
1985, Journal of Paleontology (59) 446-460
Nonmarine ostracodes occur as partly exfoliated carapaces and internal molds at the base of the Bramwell Member of the Bluestone Formation, which represents the uppermost Mississippian (Namurian A), stratigraphic subdivision in West Virginia and Virginia. These specimens are important in that they permit the determination of a variety of adductor-muscle-attachment...
