Experiments with central-limit properties of spatial samples from locally covariant random fields
T. H. Barringer, T. E. Smith
1992, Regional Science and Urban Economics (22) 387-403
When spatial samples are statistically dependent, the classical estimator of sample-mean standard deviation is well known to be inconsistent. For locally dependent samples, however, consistent estimators of sample-mean standard deviation can be constructed. The present paper investigates the sampling properties of one such estimator, designated as the tau estimator of sample-mean standard...
One-level prediction-A numerical method for estimating undiscovered metal endowment
R.B. McCammon, J.O. Kork
1992, Nonrenewable Resources (1) 139-147
One-level prediction has been developed as a numerical method for estimating undiscovered metal endowment within large areas. The method is based on a presumed relationship between a numerical measure of geologic favorability and the spatial distribution of metal endowment. Metal endowment within an unexplored area for which the favorability measure...
The Mount Edgecumbe tephra deposits, a marker horizon in southeastern Alaska near the Pleistocene-Holocene boundary
J.R. Riehle, D.H. Mann, D.M. Peteet, D.R. Engstrom, D. A. Brew, C.E. Meyer
1992, Quaternary Research (37) 183-202
Late Pleistocene tephra deposits found from Sitka to Juneau and Lituya Bay are assigned to a source at the Mount Edgecumbe volcanic field, based on similarity of glass compositions to nearvent deposits and on thinning away from Kruzof Island. The sequence of near-vent layers is basaltic andesite and andesite at...
Morphology of ruffe (Gymnocephalus cernuus) protolarvae from the St. Louis River, Lake Superior
John R. P. French III, Thomas A. Edsall
1992, Journal of Freshwater Ecology (7) 59-68
We describe hatching and the morphological and meristic characteristics of 2.5-5.6 mm long ruffe protolarvae (Gymnocephalus cernuus). Eggs and sperm from St. Louis River ruffe were mixed, producing fertilized eggs that were 0.9-1.2 mm in diameter. Newly hatched protolarvae were 2.5-3.2 mm long. They had 14-15 preanal...
Use of forecasting signatures to help distinguish periodicity, randomness, and chaos in ripples and other spatial patterns
D. M. Rubin
1992, Chaos (2) 525-536
Forecasting of one-dimensional time series previously has been used to help distinguish periodicity, chaos, and noise. This paper presents two-dimensional generalizations for making such distinctions for spatial patterns. The techniques are evaluated using synthetic spatial patterns and then are applied to a natural example: ripples formed in sand by blowing...
The effect of membrane filtration artifacts on dissolved trace element concentrations
A. J. Horowitz, K. A. Elrick, M.R. Colberg
1992, Water Research (26) 753-763
Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration,...
The study of the undiscovered mineral resources of the Tongass National Forest and adjacent lands, Southeastern Alaska
D. A. Brew, L.J. Drew, S. D. Ludington
1992, Nonrenewable Resources (1) 303-322
The quantitative probabilistic assessment of the undiscovered mineral resources of the 17.1-million-acre Tongass National Forest (the largest in the United States) and its adjacent lands is a nonaggregated, mineral-resource-tract-oriented assessment designed for land-planning purposes. As such, it includes the renewed use of gross-in-place values (GIPV's) in dollars of the estimated...
Sampling design for spatially distributed hydrogeologic and environmental processes
G. Christakos, Ricardo A. Olea
1992, Advances in Water Resources (15) 219-237
A methodology for the design of sampling networks over space is proposed. The methodology is based on spatial random field representations of nonhomogeneous natural processes, and on optimal spatial estimation techniques. One of the most important results of random field theory for physical sciences is its rationalization of correlations in...
Evaluation of models proposed for the 1991 revision of the International Geomagnetic Reference Field
N.W. Peddie
1992, Journal of Geomagnetism & Geoelectricity (44) 793-803
The 1991 revision of the International Geomagnetic Reference Field (IGRF) comprises a definitive main-field model for 1985.0, amain-field model for 1990.0, and a forecast secular-variation model for the period 1990-1995. The five 1985.0 main-field models and five 1990.0 main-field models that were proposed have been evaluated by comparing...
40Ar/39Ar dating of Quaternary feldspar: Examples from the Taupo Volcanic Zone, New Zealand
M. S. Pringle, M. McWilliams, Bruce F. Houghton, M. A. Lanphere, C. J. N. Wilson
1992, Geology (20) 531-534
Using a continuous laser and resistance furnace, we have measured ages on Quaternary plagioclase with an absolute precision of about ±30 ka and on Quaternary sanidine with a relative precision of better than 1%. Such precision was achieved by using low-temperature heating steps to remove much of the nonradiogenic argon...
Pesticides in Iowa precipitation
B.K. Nations, G.R. Hallberg
1992, Journal of Environmental Quality (21) 486-492
Rainfall was sampled for pesticides to assess their occurrence in precipitation and potential impacts on water resources. Three areas in Iowa were sampled; two localities were in rural settings, and a third in an urban area. Fourteen pesticides, including ten herbicides and four insecticides, were detected...
Organic matter diagenesis as the key to a unifying theory for the genesis of tabular uranium-vanadium deposits in the Morrison Formation, Colorado Plateau
P. L. Hansley, C.S. Spirakis
1992, Economic Geology (87) 352-365
Interstitial, epigenetic amorphous organic matter is intimately associated with uranium in the Grants uranium region on the southern part of the Colorado Plateau in northwestern New Mexico and is considered essential to genetic models for these deposits. In contrast, uranium minerals are intimately associated with authigenic vanadium chlorite and vanadium...
Laser-excited fluorescence of rare earth elements in fluorite: Initial observations with a laser Raman microprobe
R.C. Burruss, T.G. Ging, R. G. Eppinger, a.M. Samson
1992, Geochimica et Cosmochimica Acta (56) 2713-2723
Fluorescence emission spectra of three samples of fluorite containing 226–867 ppm total rare earth elements (REE) were excited by visible and ultraviolet wavelength lines of an argon ion laser and recorded with a Raman microprobe spectrometer system. Narrow emission lines (< 1 nm) due to 4f-4f electron transitions in individual...
Age and nature of the basement in northeastern Washington and northern Idaho: isotopic evidence from Mesozoic and Cenozoic granitoids
M.J. Whitehouse, J. S. Stacey, F. K. Miller
1992, Journal of Geology (100) 691-701
K-feldspar Pb and whole rock Nd isotopic analyses from 25 Mesozoic and Cenozoic plutonic rocks and two gneisses from NE Washington and northern Idaho are used to elucidate the age and nature of the concealed cratonic basement. The plutons form two highly...
Placer and lode platinum-group minerals in south Kalimantan, Indonesia: Evidence for derivation from Alaskan-type ultramafic intrusions
M. L. Zientek, B. Pardiarto, H. R. W. Simandjuntak, A. Wikrama, Robert L. Oscarson, A. L. Meier, R. R. Carlson
1992, Australian Journal of Earth Sciences (39) 405-417
Platinum‐group element minerals (PGM) occur in significant proportions in placer deposits in several localities in South Kalimantan. They consist of Pt‐Fe alloy that may be intergrown with or contain inclusions of Ir‐Os‐Ru alloy, laurite and chromite. Alluvial PGM found along Sungai Tambanio are in part derived from chromitite schlieren in...
Semiempirical model of soil water hysteresis
J. R. Nimmo
1992, Soil Science Society of America Journal (56) 1723-1730
In order to represent hysteretic soil water retention curves accurately using as few measurements as possible, a new semiempirical model has been developed. It has two postulates related to physical characteristics of the medium, and two parameters, each with a definite physical interpretation, whose values are determined empirically for a...
Utility of radiocarbon-dated stratigraphy in determining late Holocene earthquake recurrence intervals, upper Cook Inlet region, Alaska
S. Bartsch-Winkler, H. R. Schmoll
1992, Geological Society of America Bulletin (104) 684-694
During the great 1964 earthquake, parts of coastal southern Alaska subsided tectonically as much as 2 m, and this led to burial of high-intertidal organic-rich marshes by low-intertidal and tidal silt. In the tectonically active part of upper Cook Inlet, the presence of stratigraphic sections containing numerous prehistoric interbedded layers...
Immunostimulants, adjuvants, and vaccine carriers in fish: Applications to aquaculture
Douglas P. Anderson
1992, Annual Review of Fish Diseases (2) 281-307
Use of immunostimulants, adjuvants, and vaccine carriers in fish culture offers a wide range of attractive methods for inducing and building up protection against diseases. Immunostimulants and adjuvants can be administered before, with, or after vaccines to amplify the specific immune response generating elevations of circulating antibody titers and...
Surface chemistry associated with the cooling and subaerial weathering of recent basalt flows
A. F. White, M.F. Hochella Jr.
1992, Geochimica et Cosmochimica Acta (56) 3711-3721
The surface chemistry of fresh and weathered historical basalt flows was characterized using surface-sensitive X-ray photoelectron spectroscopy (XPS). Surfaces of unweathered 1987–1990 flows from the Kilauea Volcano, Hawaii, exhibited variable enrichment in Al, Mg, Ca, and F due to the formation of refractory fluoride compounds and pronounced depletion in Si...
Hydrogeochemical exploration of geothermal prospects in the Tecuamburro Volcano region, Guatemala
C. J. Janik, F. Goff, L. Fahlquist, A.I. Adams, Roldan M. Alfredo, S.J. Chipera, P.E. Trujillo, D. Counce
1992, Geothermics (21) 447-481
Chemical and isotopic analyses of thermal and nonthermal waters and of gases from springs and fumaroles are used to evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Chemically distinct geothermal surface manifestations generally occur in separate hydrogeologic areas within this 400 km2 region: low-pressure fumaroles with temperatures near local...
Factors controlling the major ion chemistry of streams in the Blue Ridge and Valley and Ridge physiographic provinces of Virginia and Maryland
L.J. Puckett, O.P. Bricker
1992, Hydrological Processes (6) 79-98
The factors controlling the chemistry of 69 low-order streams in the Blue Ridge and Valley and Ridge physiographic provinces of Virginia and Maryland were studied over a 13-month period. Principal component analysis was used to examine regional patterns in stream chemistry and to examine...
Small explosions interrupt 3-year quiescence at Mount St. Helens, Washington
B. Myers
1992, Earthquakes & Volcanoes (USGS) (23) 58-73
On December 11, 1989, geologists working in the crater at Mount St. Helens discovered two thin layers of ash separated by fresh snow-clear evidence that at least two small explosions had occurred recently. The explosions were neither seen nor heard, but on December 7 scientists suspected that a small ash-producing...
Tectonic framework of the Northern California continental margin
S. H. Clarke Jr.
1992, Earthquakes & Volcanoes (USGS) (23) 94-100
The northern coast of California is one of the most seismically active regions in the continental United States. This activity is largely due to tectonic forces resulting from differing relative motions between three extensive lithospheric plates that meet in this region. These crustal plates are bounded by long fault systems-the...
Comparison of the effects of filtration and preservation methods on analyses for strontium-90 in ground water
L.L. Knobel, L. DeWayne Cecil, S.J. Wegner, L.L. Moore
1992, Environmental Monitoring and Assessment (20) 67-80
From 1952 to 1988, about 140 curies of strontium-90 were discharged in liquid waste to disposal ponds and wells at the INEL (Idaho National Engineering Laboratory). Water from four wells was sampled as part of the U.S. Geological Survey's quality-assurance program to evaluate the effects of filtration and preservation methods...
Energy, time, and channel evolution in catastrophically disturbed fluvial systems
A. Simon
1992, Geomorphology (5) 345-372
Two diverse fluvial systems show that with time, channels adjust such that the rate of energy dissipation is minimized. One fluvial system, characterized by high relief and coarse-grained sediment, was subjected to an explosive volcanic eruption; the other system, characterized by low relief and fine-grained sediment, was subjected to dredging...
