SEISMIC STUDY OF THE AGUA DE PAU GEOTHERMAL PROSPECT, SAO MIGUEL, AZORES.
Phillip B. Dawson, Antonio Rodrigues da Silva, H. M. Iyer, John R. Evans
1985, Conference Paper, Transactions - Geothermal Resources Council
A 16 station array was operated over the 200 km**2 central portion of Sao Miguel utilizing 8 permanent Instituto Nacional de Meterologia e Geofisica stations and 8 USGS portable stations. Forty four local events with well constrained solutions and 15 regional events were located. In addition, hundreds of unlocatable seismic...
Research on Alaskan polar bears in 1979 and 1980
Steven C. Amstrup
1985, Conference Paper, Polar bears: Proceedings of the eighth working meeting of the IUCN/SSC Polar Bear Specialist Group
In 1979 the U.S. Fish and Wildlife Service continued its program of mark and recapture. From 31 March to 4 May field crews working at Point Barrow, Alaska, captured and marked a total of 15 polar bears (Table I). The small number was due to very poor ice conditions off...
SURVEYS OF COASTAL STRUCTURES USING GEOPHYSICAL TECHNIQUES.
John R. Dingler, Roberto J. Anima
Billy L. Edge, editor(s)
1985, Conference Paper, Proceedings of the Coastal Engineering Conference
During the summer of 1983 and the spring and summer of 1984, the authors conducted side scan sonar and shallow subbottom surveys in conjunction with bathymetric and diving surveys along three northern California coastal structures to determine the condition of the structures before extensive damage occurred. Then the applicability of...
APPLICATIONS OF BOREHOLE-ACOUSTIC METHODS IN ROCK MECHANICS.
Frederick L. Paillet
1985, Conference Paper, Proceedings - Symposium on Rock Mechanics
Acoustic-logging methods using a considerable range of wavelengths and frequencies have proven very useful in the in situ characterization of deeply buried crystalline rocks. Seismic velocities are useful in investigating the moduli of unfractured rock, and in producing a continuous record of rock quality for comparison with discontinuous intervals of...
Terrestrial vs. marine depositional model—A new assessment of subsurface Lower Pennsylvanian rocks of southwestern Virginia
C. L. Rice
1985, Geology (13) 786-789
A reinterpretation of the origin of subsurface rocks in southwestern Virginia and southeastern Kentucky suggests that, contrary to commonly accepted ideas, the Mississippian-Pennsylvanian Systemic boundary is an unconformity and the Lower Pennsylvanian quartz arenite sequences were deposited in a fluvial environment. Because Pennsylvanian...
TRANSIENT SOUNDING INVESTIGATION OF NEWBERRY VOLCANO, OREGON.
David V. Fitterman, Deborah K. Neev
1985, Conference Paper, Transactions - Geothermal Resources Council
Transient electromagnetic soundings were used to map the geoelectrical structure of Newberry Volcano in central Oregon. An extensive conductor was found to underlie the volcano and to have resistivities from 20 OMEGA m to 72 OMEGA m. The depth to the conductor ranges from 410 m to 870 m. Inside...
MAJOR SOURCE OF SIDE-LOOKING AIRBORNE RADAR IMAGERY FOR RESEARCH AND EXPLORATION: THE U. S. GEOLOGICAL SURVEY.
Allan N. Kover, John Edwin Jones
Carver Keith R., editor(s)
1985, Conference Paper, Digest - International Geoscience and Remote Sensing Symposium (IGARSS)
The US Geological Survey (USGS) instituted a program in 1980 to acquire side-looking airbore radar (SLAR) data and make these data readily available to the public in a mosaic format comparable to the USGS 1:250,000-scale topographic map series. The SLAR data are also available as strip images at an acquisition...
Seasonal variation in sediment transport on the Russian River shelf, California
D.E. Drake, D.A. Cacchione
1985, Continental Shelf Research (4) 495-514
Near-bottom currents, light transmission and scattering, and bottom pressure were measured with GEOPROBE tripods and vector-averaging current meters during June 1979 to April 1980 on the central shelf 10 km west of the Russian River, California. The instruments were located on the mid-shelf mud belt composed of bimodal sandy clayey...
An ocean bottom seismometer study of shallow seismicity near the Mid- America Trench offshore Guatemala
E. L. Ambos, D.M. Hussong, C.E. Holman
1985, Journal of Geophysical Research Solid Earth (90) 11397-11412
Five ocean bottom seismometers recorded seismicity near the Mid-America Trench offshore Guatemala for 27 days in 1979. The array was emplaced in the lower slope region, just above the topographic trench, in the area investigated during Deep Sea Drilling Project legs 67 and 84. Approximately 170 events were recorded by...
Electrical geophysical investigations of massive sulfide deposits and their host rocks, West Shasta copper-zinc district
R. J. Horton, B. D. Smith, J.C. Washburne
1985, Economic Geology (80) 2213-2229
The West Shasta copper-zinc district, Shasta County, California, contains many volcanogenic sulfide deposits within Middle Devonian rhyolites that have not been highly metamorphosed. The district was selected by the U.S. Geological Survey for intensive geological, geochemical, and geophysical study under the Development of Assessment Techniques (DAT) project because accessible exposures...
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...
More on the alleged 1970 geomagnetic jerk
L.R. Alldredge
1985, Physics of the Earth and Planetary Interiors (39) 255-264
French and United Kingdom workers have published reports describing a sudden change in the secular acceleration, called an impulse or a jerk, which took place around 1970. They claim that this change took place in a period of a year or two and that the sources of the alleged jerk...
Phase relations and adiabats in boiling seafloor geothermal systems
J. L. Bischoff, Kenneth S. Pitzer
1985, Earth and Planetary Science Letters (75) 327-338
Observations of large salinity variations and vent temperatures in the range of 380–400°C suggest that boiling or two-phase separation may be occurring in some seafloor geothermal systems. Consideration of flow rates and the relatively small differences in density between vapors and...
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...
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...
Late Holocene vegetation changes in Greenwater Valley, Mojave Desert, California
K.L. Cole, R. H. Webb
1985, Quaternary Research (23) 227-235
Small-scale late Holocene vegetation changes were determined from a series of 13 modern and fossil packrat middens collected from a site in the Greenwater Valley, northern Mojave Desert, California. Although the site is above the modern lower limit of Coleogyne ramosissima (black-brush), macrofossils of this shrub are only present in...
Electrical Techniques for Engineering Applications
Robert J. Bisdorf
1985, Bulletin of the Association of Engineering Geologists (22) 421-433
Surface electrical geophysical methods have been used in such engineering applications as locating and delineating shallow gravel deposits, depth to bedrock, faults, clay zones, and other geological phenomena. Other engineering applications include determining water quality, tracing ground water contaminant plumes and locating dam seepages. Various methods and electrode arrays are...
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...
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...
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 =...
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...
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...
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...
