Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion
John D. Bredehoeft, Richard A. Young
1983, Water Resources Research (19) 1111-1121
In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what...
Scoresum - A technique for displaying and evaluating multi-element geochemical information, with examples of its use in regional mineral assessment programs
M.A. Chaffee
1983, Journal of Geochemical Exploration (19) 361-381
A technique called SCORESUM was developed to display a maximum of multi-element geochemical information on a minimum number of maps for mineral assessment purposes. The technique can be done manually for a small analytical data set or can be done with a computer for a large data set. SCORESUM...
Quaternary geology of the Rhode Island inner shelf
S. W. Needell, C. J. O’Hara, H.J. Knebel
1983, Marine Geology (53) 41-53
Five sedimentary units and three erosional unconformities identified in high-resolution seismic-reflection profiles reveal the stratigraphic framework and Quaternary history of the inner continental shelf south of Narragansett Bay, Rhode Island. Late Tertiary to early Pleistocene rivers eroded the pre-Mesozoic bedrock and the Upper Cretaceous to lower Tertiary coastal plain and...
40Ar/39Ar and U-Th-Pb dating of separated clasts from the Abee E4 chondrite
D.D. Bogard, D.M. Unruh, M. Tatsumoto
1983, Earth and Planetary Science Letters (62) 132-146
Determinations of40Ar/39Ar and U-Th-Pb are reported for three clasts from the Abee (E4) enstatite chondrite, which has been the object of extensive consortium investigations. The clasts give40Ar/39Ar plateau ages and/or maximum ages of 4.5 Gy, whereas two of the clasts give...
Incorporation of prior information on parameters into nonlinear regression groundwater flow models: 2. Applications
Richard L. Cooley
1983, Water Resources Research (19) 662-676
This paper investigates factors influencing the degree of improvement in estimates of parameters of a nonlinear regression groundwater flow model by incorporating prior information of unknown reliability. Consideration of expected behavior of the regression solutions and results of a hypothetical modeling problem lead to several general conclusions. First, if the...
Rare-earth element geochemistry and the origin of andesites and basalts of the Taupo Volcanic Zone, New Zealand
J. W. Cole, K. V. Cashman, P.C. Rankin
1983, Chemical Geology (38) 255-274
Two types of basalt (a high-Al basalt associated with the rhyolitic centres north of Taupo and a "low-Al" basalt erupted from Red Crater, Tongariro Volcanic Centre) and five types of andesite (labradorite andesite, labradorite-pyroxene andesite, hornblende andesite, pyroxene low-Si andesite and olivine andesite/low-Si andesite) occur in the Taupo Volcanic Zone...
Orickite and coyoteite, two new sulfide minerals from Coyote Peak, Humboldt County, California.
Richard C. Erd, G.K. Czamanske
1983, American Mineralogist (68) 245-254
Minute quantities of orickite and coyoteite occur with rare alkali iron sulphides in a mafic alkalic diatreme near Orick, Humboldt County. Orickite, NaxKyCu0.95Fe1.06zH2O (x,y < 0.03, z < 0.5), is hexagonal, a 3.695, c 6.16 A, D 4.212 g/cm3, Z = 4. The strongest XRD reflections are 3.08(100), 3.20(90), 2.84(60),...
Refractive index determination using the central focal masking technique with dispersion colors.
R.E. Wilcox
1983, American Mineralogist (68) 1226-1236
The procedures, precision, advantages and limitations of central focal masking ("dispersion staining'), a technique for determining the refractive indices of microfragments by the immersion method and for distinguishing between minerals in an immersion mount, are described. -J.A.Z....
Two classes of volcanic plumes on Io
A. S. McEwen, L.A. Soderblom
1983, Icarus (55) 191-217
Comparison of Voyager 1 and Voyager 2 images of the south polar region of Io has revealed that a major volcanic eruption occured there during the period between the two spacecraft encounters. An annular deposit ∼1400 km in diameter formed around the Aten Patera caldera (311°W, 48°S), the floor of...
Two examples of earthquake- hazard reduction in southern California.
W. J. Kockelman, C.C. Campbell
1983, Earthquake Information Bulletin (USGS) (15) 216-225
Because California is seismically active, planners and decisionmakers must try to anticipate earthquake hazards there and, where possible, to reduce the hazards. Geologic and seismologic information provides the basis for the necessary plans and actions. Two examples of how such information is used are presented. The first involves assessing the...
Tectonics and metallogenic provinces
P. W. Guild
1983, Advances in Space Research (3) 9-16
Various theories have been advanced to explain the well-known uneven distribution of metals and ore-deposit types in space and time. Primordial differences in the mantle, preferential concentration of elements in the crust, the prevalence of ore-forming processes at certain times and (or) places, and combinations of one or several of...
ROLES OF REMOTE SENSING AND CARTOGRAPHY IN THE USGS NATIONAL MAPPING DIVISION.
Rupert B. Southard, John W. Salisbury
1983, Conference Paper, Technical Papers of the American Congress of Surveying and Mapping
The inseparable roles of remote sensing and photogrammetry have been recognized to be consistent with the aims and interests of the American Society of Photogrammetry. In particular, spatial data storage, data merging and manipulation methods and other techniques originally developed for remote sensing applications also have applications for digital cartography....
Hole-to-surface resistivity measurements
J.J. Daniels
1983, Geophysics (48) 87-97
Hole-to-surface resistivity measurements over a layered volcanic tuff sequence illustrate procedures for gathering, reducing, and interpreting hole-to-surface resistivity data. The magnitude and direction of the total surface electric field resulting from a buried current source is calculated from orthogonal potential difference measurements for a grid of closely spaced stations. A...
Mineral discrimination using a portable ratio-determining radiometer
G. Whitney, M. J. Abrams, Alexander F.H. Goetz
1983, Economic Geology (78) 688-698
The instrument has ten bands in the visible and near-infrared portion of the spectrum (0.5-2.4 mu m). Measurements and statistical analyses were performed on 66 samples, which were characterized by microscopic and X-ray diffraction analyses. On the ability to discriminate between 16 mineralogical groups, 91 percent classification accuracy was achieved....
Palaeomagnetism of lower cretaceous tuffs from Yukon-Kuskokwim delta region, western Alaska
B.R. Globerman, R. S. Coe, J. M. Hoare, J. Decker
1983, Nature (305) 516-520
During the past decade, the prescient arguments1-3 for the allochthoneity of large portions of southern Alaska have been corroborated by detailed geological and palaeomagnetic studies in south-central Alaska 4-9 the Alaska Peninsula10, Kodiak Island11,12 and the Prince William Sound area13 (Fig. 1). These investigations have demonstrated sizeable northward displacements for...
RECENT DEVELOPMENTS ON THE ORIGIN OF MINERAL MATTER IN COAL.
C. B. Cecil, R.W. Stanton, F.T. Dulong, L.P. Ruppert
1983, Conference Paper
This study attempts to quantify some of the various origins of mineral matter. Data developed for the Upper Freeport coal bed indicates that mineral matter other than pyrite and calcite is primarily derived from the vegetal matter that ultimately became coal. Cathodoluminesence was used to verify that the quartz in...
Selective dissolution of siliceous microfossils observed in a box core from the north-east equatorial Pacific
D. Kadko, J. R. Blueford, L.H. Burckle, J. Barron
1983, Nature (302) 139-141
A box core taken at 11??50.3??? N and 137??28.2??? W in the Central Pacific manganese nodule province was studied to determine the pattern of diatom and radiolarian preservation with depth in the sediment, as well as to observe downcore variations in clay mineralogy. We observed marked deterioration of the siliceous...
Platinum-group elements in rocks from the voikar-syninsky ophiolite complex, Polar Urals, U.S.S.R.
N.J. Page, P. J. Aruscavage, J. Haffty
1983, Mineralium Deposita (18) 443-455
Analyses of platinum-group elements (PGE) in rocks collected from the Voikar-Syninsky ophiolite in the Polar Urals suggest that the distribution and geochemistry of PGE in this Paleozoic ophiolite are similar to those in Mesozoic ophiolites from elsewhere. Chondrite-normalized PGE patterns for chromitite, the tectonite unit, and ultramafic and mafic cumulate...
The past is the key to the future
B. R. Doe
1983, Geochimica et Cosmochimica Acta (47) 1341-1354
A new major frontier of geological research, which was initiated in the 1970's, involves predicting future geologic trends or events through study of the present and past, rather than trying to understand the past, often using what one knows about the present. Like most scientific frontiers, this one began from...
Estimation of groundwater recharge parameters by time series analysis
Richard L. Naff, Allan L. Gutjahr
1983, Water Resources Research (19) 1531-1546
A model is proposed that relates water level fluctuations in a Dupuit aquifer to effective precipitaton at the top of the unsaturated zone. Effective precipitation, defined herein as that portion of precipitation which becomes recharge, is related to precipitation measured in a nearby gage by a two-parameter function. A second-order...
Lake phosphorus loading form septic systems by seasonally perched groundwater
R. J. Gilliom, C.R. Patmont
1983, Journal of the Water Pollution Control Federation (55) 1297-1305
The movement of effluent phosphorus (P) from old septic systems by seasonally perched groundwater was investigated. A previous study indicated a correlation between P loadings and the presence of old homes. Water samples were taken from shallow wells installed 10 to 50 m downgradient from seven septic systems 20 to...
Intensity patterns in eastern Asia.
J. F. Evernden
1983, Chinese Geophysics (2) 405-438
Investigation of the intensity patterns of earthquakes of E Asia indicates a strong regional pattern of attenuation parameter k and systematic correlation of this pattern with topography, P residuals, and level of seismicity as in the USA.-Author...
Storm-controlled oblique dunes of the Oregon coast
R. E. Hunter, B. M. Richmond, T. R. Alpha
1983, Geological Society of America Bulletin (94) 1450-1465
The large (mean height 25 m, spacing 300 m), relatively straight-crested dunes of the central Oregon coast migrate an average of 3.8 m/yr toward an azimuth of 26°. The dunes are transverse to the strong, south-southwesterly winter storm winds that are responsible for...
The saltwater-freshwater interface in the Tertiary limestone aquifer, southeast Atlantic outer-continental shelf of the U.S.A.
R.H. Johnston
1983, Journal of Hydrology (61) 239-249
Hydrologic testing in an offshore oil well abandoned by Tenneco, Inc., determined the position of the saltwater-freshwater interface in Tertiary limestones underlying the Florida-Georgia continental shelf of the U.S.A. Previous drilling (JOIDES and U.S.G.S. AMCOR projects) established the existence of freshwater far offshore in this area. At the Tenneco well...
Recent geologic development of Lake Michigan (U.S.A.)
D.L. Gross, R.A. Cahill
1983, Hydrobiologia (103) 193-198
The stresses placed on Lake Michigan since the advent of industrialization require knowledge of the sedimentology of the whole lake in order to make informed decisions for environmental planning. Sediment accumulation rates are low: areas of the lake receiving the most sediment average only 1 mm a-1; deep-water basins average...
