Conference Papers
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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CHARACTERIZATION OF SECONDARY ALTERATION IN THE COLUMBIA RIVER BASALT BY BACKSCATTERED ELECTRON IMAGING AND ENERGY-DISPERSIVE X-RAY SPECTROSCOPY.
The thick sequences of flood basalts which underlie the Columbia River basin are important aquifiers, providing water for both agricultural and domestic use. Secondary alteration in these rocks occurs primarily as coatings or fillings in fractures and vesicles; alteration is generally believed to have occurred at low temperatures ( less than 100 C) by reaction with meteroic waters. The distributio
Authors
P.P. Hearn, W.C. Steinkampf, Z. A. Brown
Characterization of the oil shale of the New Albany Shale in Indiana
In the 1920's chemical and mineralogic characterization of the New Albany Shale (Mississippian-Devonian) in Indiana showed the dark shale to be rich in organic material and have commercial possibilities. Projects in the 1960's resulted in disparaging descriptions of exiguous fossil record, monotonous mineralogy, and intractable chemistry. Since 1978 expanded efforts have yielded much new informati
Authors
R. K. Leininger, J.G. Hailer, N.R. Shaffer
COORDINATION OF FEDERAL DIGITAL CARTOGRAPHIC ACTIVITIES.
Throughout the Federal Government, applications are emerging for spatial data bases that require digital cartographic data as a framework. This paper describes some major applications of spatial data in the Federal Government, and it discusses the extent to which these data needs are being coordinated. Efforts are outlined towards further coordination of digital cartographic data bases and product
Authors
R.B. Southard, L.L. Amos, Kirk E. Anderson
DEFINITION FOR ASBESTOS.
A definition of asbestos is proposed. Under this definition, the term asbestos applies to six naturally occurring minerals exploited commercially for their desirable physical properties, which are in part derived from their asbestiform habit. The six minerals are the serpentine mineral chrysotile and the amphibole minerals grunerite asbestos (also referred to as amosite), riebeckite asbestos (also
Authors
Malcolm Ross, Richard A. Kuntze, Robert A. Clifton
DEFINITION FOR TALC.
Talc is a naturally occurring single-phase mineral having the approximate chemical formula Mg//3Si//4O//1//0(OH)//2 and a specific type of crystal structure. Talc commonly forms by hydrothermal alteration of rocks rich in magnesium and iron (ultramafic rocks) and by low-grade thermal metamorphism of siliceous dolomites. The fact that talc often occurs in association with other minerals, or that it
Authors
Malcolm Ross
Differential predation on wintering dunlin: age-specific variation in flocking behavior
No abstract available at this time
Authors
B.E. Kus
DIGITAL PROCESSING TECHNIQUES FOR IMAGE MAPPING WITH LANDSAT TM AND SPOT SIMULATOR DATA.
To overcome certain problems associated with the visual selection of Landsat TM bands for image mapping, the author used a quantitative technique that ranks the 20 possible three-band combinations based upon their information content. Standard deviations and correlation coefficients can be used to compute a value called the Optimum Index Factor (OIF) for each of the 20 possible combinations. SPOT
Authors
Pat S. Chavez
DISCRIMINATION OF GRANITOIDS AND MINERALIZED GRANITOIDS IN THE MIDYAN REGION, NORTHWESTERN ARABIAN SHIELD, SAUDI ARABIA, BY LANDSAT MSS DATA-ANALYSIS.
Landsat multispectral scanner (MSS) band and band-ratio databases of two scenes covering the Midyan region of northwestern Saudi Arabia were examined quantitatively and qualitatively to determine which databases best discriminate the geologic units of this semi-arid and arid region. Unsupervised, linear-discriminant cluster-analysis was performed on these two band-ratio combinations and on the MSS
Authors
Philip A. Davis, Maurice J. Grolier
Disturbance vs. competition: the influence of Pacific winter storms on intertidal community organizationn at San Nicolas Island, California
No abstract available at this time
Authors
J. A. Estes, D. R. Lindberg
EFFECT ON BRIDGE PIERS ON STREAMFLOW AND CHANNEL GEOMETRY.
Piers in the waterway affect the velocity distribution across the channel and may act as barriers to floating debris. In addition, they also affect channel geometry by causing general and local scour in the vicinity of the bridge. The level of hydraulic efficiency of an unobstructed channel may be reduced by several percent if piers are placed in the waterway. Pier design should consider the proba
Authors
James C. Blodgett
EFFECTS OF HIGH SEDIMENT CONCENTRATIONS ON VELOCITY AND SEDIMENT DISTRIBUTIONS.
Several classifications are required to describe sediment-transporting flow. The flow may be turbulent or laminar, Newtonian or non-Newtonian, and may also have a uniform or nonuniform concentration profile. As sediment concentration or transport increases, the character of flow changes. Generally, fall velocity and effective fall diameter decrease. The viscosity of the mixture increases. The flow
Authors
Steve C. McCutcheon, Jeffrey B. Bradley