Refinement of the evaluation of the role of CO2 in modifying estimates of the pressure of epithermal mineralization
P.B. Barton, I.-M. Chou
1993, Economic Geology (88) 873-884
Pressure is the most important of the intensive parameters for relating epithermal mineralization to the geologic setting. This paper describes the limitations on pressure (and therefore depth) of mineralization that may reasonably be derived from simple observations of the behavior of fluid inclusions (i.e., the existence of ice or CO 2 clathrate...
Landslides caused by the Klamath Falls, Oregon, earthquakes of September 20, 1993
D. K. Keefer, R. L. Schuster
1993, Earthquakes & Volcanoes (USGS) (24) 140-146
The Klamath Falls earthquakes caused landslides throughout an area of about 420 sq km and as far as about 29 km from the epicenter, a distribution that is typical for magnitude 6 earthquakes (see graphs on following pages). Most of the landslides were rock falls or shallow, highly disrupted rock...
Tracing the migrations of estuarine and coastal fishes using otolith microchemistry
D.H. Secor, E.D. Houde, A. Henderson-Arzapalo, P.M. Piccoli
1993, Report, International Council for the Exploration of the Sea (C.M. 1993 M-41)
No abstract available at this time...
Model for episodic flow of high-pressure water in fault zones before earthquakes
J. Byerlee
1993, Geology (21) 303-306
In this model for the evolution of large crustal faults, water that originally came from the country rock saturates the initially highly porous and permeable fault zone. During shearing, the fault zone compacts and water flows back into the country rock, but the...
Freshwater temperate fish viruses
P. E. McAllister
M. K. Stoskopf, editor(s)
1993, Book chapter, Fish medicine
No abstract available at this time...
Annual and Spatial Variation of the Kelp Forest Fish Assemblage at San Nicolas Island, California
R.J. Cowen, James L. Bodkin
1993, Conference Paper, Third California Islands Symposium
The kelp forest fishes of San Nicolas Island, California were studied from 1981-1986 to examine the causes of among-site and among-year variation in the fish assemblages. Fish counts and seven physical and biological variables were recorded at six sites around the island every spring and fall. Over the study period,...
Cold-water fish viruses
P. E. McAllister
M. K. Stoskopf, editor(s)
1993, Book chapter, Fish medicine
No abstract available at this time...
Sedimentary environments within a glaciated estuarine-inner shelf system: Boston Harbor and Massachusetts Bay
H.J. Knebel
1993, Marine Geology (110) 7-30
Three modern sedimentary environments have been identified and mapped across the glaciated Boston Harbor estuary and adjacent inner shelf of Massachusetts Bay by means of an extensive set of sidescan sonar records and supplemental bathymetric, sedimentary, subbottom and bottom-current data. 1. (1) Environments of erosion and nondeposition appear on the...
Effect of treated-sewage contamination upon bacterial energy charge, adenine nucleotides, and DNA content in a sandy aquifer on Cape Cod
David W. Metge, Myron H. Brooks, Richard L. Smith, Ronald W. Harvey
1993, Applied and Environmental Microbiology (59) 2304-2310
Changes in adenylate energy charge (ECA) and in total adenine nucleotides (AT) and DNA content (both normalized to the abundance of free-living, groundwater bacteria) in response to carbon loading were determined for a laboratory-grown culture and for a contaminated aquifer. The latter study involved a 3-km-long transect through a contaminant...
Variations in northern Sierra Nevada streamflow. Implications of climate change
A. Pupacko
1993, Water Resources Bulletin (29) 283-290
Historical records of streamflow for an eastward- and a westward-draining stream in the northern Sierra Nevada have been analyzed for evidence of changes in runoff characteristics and patterns of variability. A trend of increasing and more variable winter streamflow began in the mid-1960s. Mean monthly streamflow during December through March...
Seismic response of eccentrically braced tall buildings
Mehmet Çelebi
1993, Journal of Structural Engineering (119) 1188-1205
Spectral analysis and system identification techniques are used to analyze a set of acceleration reponse records obtained during the Loma Prieta earthquake from the 47-story, moment-resisting framed and eccentrically braced Embarcadero Building (EMB). The EMB was constructed in 1979 based on the 1976 Uniform Building Code requirements and a design...
Factors controlling the geochemical evolution of fumarolic encrustations, Valley of Ten Thousand Smokes, Alaska
L.G. Kodosky, T. E. C. Keith
1993, Journal of Volcanology and Geothermal Research (55) 185-200
Factor and canonical correlation analysis of geochemical data from eight fossil fumaroles suggest that six major factors controlled the formation and evolution of fumarolic encrustations on the 1912 ash-flow sheet in the Valley of Ten Thousand Smokes (VTTS). The six-factor solution model explains a large proportion (low of 74% for...
Supply of large woody debris in a stream channel
Timothy H. Diehl, Bradley A. Bryan
1993, Conference Paper, Proceedings - National Conference on Hydraulic Engineering
The amount of large woody debris that potentially could be transported to bridge sites was assessed in the basin of the West Harpeth River in Tennessee in the fall of 1992. The assessment was based on inspections of study sites at 12 bridges and examination of channel reaches between bridges....
The deposit size frequency method for estimating undiscovered uranium deposits
R.B. McCammon, W.I. Finch
1993, Nonrenewable Resources (2) 106-112
The deposit size frequency (DSF) method has been developed as a generalization of the method that was used in the National Uranium Resource Evaluation (NURE) program to estimate the uranium endowment of the United States. The DSF method overcomes difficulties encountered during the NURE program when geologists were asked to...
Deformation of the Wineglass Welded Tuff and the timing of caldera collapse at Crater Lake, Oregon
H. Kamata, K. Suzuki-Kamata, C. R. Bacon
1993, Journal of Volcanology and Geothermal Research (56) 253-265
Four types of deformation occur in the Wineglass Welded Tuff on the northeast caldera rim of Crater Lake: (a) vertical tension fractures; (b) ooze-outs of fiamme: (c) squeeze-outs of fiamme; and (d) horizontal pull-apart structures. The three types of plastic deformation (b-d) developed in the lower part of the Wineglass...
Selective inhibition of ammonium oxidation and nitrification-linked N2O formation by methyl fluoride and dimethyl ether
L.G. Miller, M.D. Coutlakis, R.S. Oremland, B.B. Ward
1993, Applied and Environmental Microbiology (59) 2457-2464
Methyl fluoride (CH3F) and dimethyl ether (DME) inhibited nitrification in washed-cell suspensions of Nitrosomonas europaea and in a variety of oxygenated soils and sediments. Headspace additions of CH3F (10% [vol/vol]) and DME (25% [vol/vol]) fully inhibited NO2- and N2O production from NH4+ in incubations of N. europaea, while lower concentrations of these gases resulted in...
Active volcanism beneath the West Antarctic ice sheet and implications for ice-sheet stability
D. D. Blankenship, R.E. Bell, S. M. Hodge, J. M. Brozena, John C. Behrendt, C. A. Finn
1993, Nature (361) 526-529
IT is widely understood that the collapse of the West Antarctic ice sheet (WAIS) would cause a global sea level rise of 6 m, yet there continues to be considerable debate about the detailed response of this ice sheet to climate change1-3. Because its bed is grounded well below sea...
Entropy and structure of silicate glasses and melts
P. Richet, R. A. Robie, B. S. Hemingway
1993, Geochimica et Cosmochimica Acta (57) 2751-2766
Low-temperature adiabatic Cp measurements have been made on NaAlSi2O6, MgSiO3, Ca3Al2Si3O12 and Ca1.5Mg1.5Al2Si3O12 glasses. Above about 50 K, these and previous data show that the heat capacity is an additive function of composition to within ±1% throughout the investigated glassforming part of the system CaO-MgO-Al2O3-SiO2. In view of the determining role of oxygen coordination...
Characterizing the hydrogeologic framework of the Death Valley region, Southern Nevada and California
Claudia Faunt, Frank D'Agnese, Joe S. Downey, A. Keith Turner
1993, Conference Paper, High Level Radioactive Waste Management
Three-dimensional (3-D) hydrogeologic modeling of the complex geology of the Death Valley region requires the application of a number of Geoscientific Information System (GSIS) techniques. This study, funded by United States Department of Energy as a part of the Yucca Mountain Project, focuses on an area of approximately 100,000 square...
Strontium isotopic evidence for a higher water table at Yucca Mountain
Brian D. Marshall, Zell E. Peterman, John S. Stuckless
1993, Conference Paper, High Level Radioactive Waste Management
At Yucca Mountain, calcite occurs as open-space fillings and coatings on fractures within much of the host volcanic rocks in both the saturated and unsaturated zones. Strontium isotope analyses of these calcites divide the samples into two groups corresponding to their location in either the saturated or unsaturated zones. The...
An objective replacement method for censored geochemical data
R.F. Sanford, C. T. Pierson, R. A. Crovelli
1993, Mathematical Geology (25) 59-80
Geochemical data are commonly censored, that is, concentrations for some samples are reported as "less than" or "greater than" some value. Censored data hampers statistical analysis because certain computational techniques used in statistical analysis require a complete set of uncensored data. We show that the simple substitution method for creating...
Analysis of the seismic origin of landslides: Examples from the New Madrid seismic zone
R.W. Jibson, D. K. Keefer
1993, Geological Society of America Bulletin (105) 521-536
By analyzing two landslides in the New Madrid seismic zone, we develop an approach for judging if a landslide or group of landslides of unknown origin was more likely to have formed as a result of earthquake shaking or in aseismic conditions. The two landslides analyzed are representative of two...
Factors Affecting 14C Ages of Lacustrine Carbonates: Timing and Duration of the Last Highstand Lake in the Lahontan Basin
L. Benson
1993, Quaternary Research (39) 163-174
Two processes contribute to inaccurate 14C age estimates of carbonates precipitated within the Lahontan basin, NevadaCalifornia: low initial 14C/C ratios in lake water (reservoir effect) and addition of modern carbon to calcium carbonate after its precipitation. The mast reliable set of 14C ages on carbonates from elevations > 1310 m...
The geochemistry of methane in Lake Fryxell, an amictic, permanently ice-covered, antarctic lake
R. L. Smith, L.G. Miller, B.L. Howes
1993, Biogeochemistry (21) 95-115
The abundance and distribution of dissolved CH4 were determined from 1987-1990 in Lake Fryxell, Antarctica, an amictic, permanently ice-covered lake in which solute movement is controlled by diffusion. CH4 concentrations were < 1 ??M in the upper oxic waters, but increased below the oxycline to 936 ??M at 18 m....
Geothermometry and water-rock interaction in selected thermal systems in the Cascade Range and Modoc Plateau, western United States
Robert H. Mariner, T. S. Presser, William C. Evans
1993, Geothermics (22) 1-15
The sulfate—water isotope geothermometer indicates higher equilibrium temperatures than the silica or cation ratio geothermometers for the Na—Cl and Na—Ca—Cl thermal waters of the Cascade Range, Oregon and the Na—SO4 thermal waters of the Modoc Plateau, northeastern California. Sulfate concentrations in the Na—Ca—Cl waters decrease as σ18O values of the dissolved...
