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A generalized model of humic materials in soils and sediments, which is consistent with their observed properties, is presented. This model provides a means of understanding the interaction of hydrophobic pollutants with humic materials. In this model, it is proposed that the humic materials in soils and sediments consist of...

The 2,700-Ma Vermilion Granitic Complex of northern Minnesota is a granite-migmatite terrane composed of supracrustal metasedimentary rocks, mafic rocks, tonalitic and granodioritic plutonic rocks, and granite. The metasedimentary rocks are predominantly graywacke, which has been regionally metamorphosed to garnet-sillimanite-muscovite-bearing biotite schist, and has locally undergone anatexis. The mafic rocks form...

Determinations of the aqueous solubilities of kaolinite at pH 4, and of five smectite minerals in suspensions set between pH 5 and 8, were undertaken with mineral suspensions adjusted to approach equilibrium from over- and undersaturation. After 1,237 days, Dry Branch, Georgia kaolinite...

One hundred and fifty new measurements of the solubility of witherite were used to evaluate the equilibrium constant of the reaction BaCO3(cr) = Ba2+(aq) + CO32−(aq) between 0 and 90°C and 1 atm total pressure. The temperature dependence of the equilibrium constant is given by logK = 607.642 + 0.121098T − 20011.25/T − 236.4948 logT where T is in degrees...

In the later Cainozoic, approx 18 m.y. ago, the first basin and range faulting developed in the central part of the Great Basin, this extensional tectonic system resulting from drag on the North American plate as the Pacific plate moved obliquely to the NW along the San Andreas fault. The...

The internal properties within and adjacent to fault zones are reviewed, principally on the basis of laboratory, borehole, and seismic refraction and reflection data. The deformation of rocks by faulting ranges from intragrain microcracking to severe alteration. Saturated microcracked and mildly fractured rocks do not exhibit a significant reduction in...

Thalenite occurs as a minor constituent of a single small pegmatite within an extensive area of granite a few miles S of Kingman, Arizona. Partly crystalline and partly metamict, this thalenite has composition Y3(Si3O10)(OH), with extensive substitution of Y by REE, especially Dy, Er and Yb. Upon heating, even at...

Problems involving the combined use of contaminant transport models and nonlinear optimization schemes can be very expensive to solve. This paper explores the use of transport models with ordinary regression and regression on ranks to develop approximate response functions of concentrations at critical locations as a function of pumping and...

A solute-transport model of an irrigated stream-aquifer system was recalibrated because of discrepancies between prior predictions of ground-water salinity trends during 1971-1982 and the observed outcome in February 1982. The original model was calibrated with a 1-year record of data collected during 1971-1972 in an 18-km reach of the Arkansas...

An inconvenience attending traditional use of associated Legendre functions in global modeling is that the functions are not separable with respect to the two indices (order and degree). In 1973 Merilees suggested a way to avoid the problem by showing that associated Legendre functions of order m and degree m+k can be expressed in...

The USGS Mini Image Processing System currently relies on a polynomial method for geometric correction of Landsat multispectral scanner (MSS) data. A large number of ground control points are required because polynomials do not model the sources of error. In order to reduce the number of necessary points, a set...

A simulation nonlinear multiple-regression methodology for estimating parameters that characterize the transport of contaminants is developed and demonstrated. Finite difference contaminant transport simulation is combined with a nonlinear weighted least squares multiple-regression procedure. The technique provides optimal parameter estimates and gives statistics for assessing the reliability of these estimates under...

The Nd, O and Sr isotopic characteristics of Precambrian metasedimentary, metavolcanic and granitic rocks from the Black Hills of South Dakota are examined. Two late-Archean granites (2.5-2.6 Ga) have Tdm ages of 3.05 and 3.30 Ga, suggesting that at least one of the granites was derived through the melting of significantly...

The need by land managers and planners for more quantitative measures of mineral values has prompted scientists at the U.S. Geological Survey to test a probabilistic method of mineral resource assessment on a portion of the wilderness lands that have been studied by the Survey during the past 20 years....

Strong-motion records from Long Valley Dam during the Mammoth Lakes earthquake sequence of May 1980 are analyzed to determine the main features of the dam's motions. The dam was instrumented with 22 accelerometers on its embankment and in the immediate vicinity, and more than 60 high-quality, long-duration accelerograms were recorded...

The magnitude 6. 1 Morgan Hill, California, earthquake of April 24, 1984, produced a set of acceleration records at the freeway overpass in San Jose carrying I-280/I-680 across U. S. 101, 12 km from the epicenter. Peak accelerations reached 0. 10 g at ground level and 0. 16 g in...

Detailed two-dimensional flow simulation of a complex ground-water system is combined with quadratic and linear programming to evaluate design alternatives for rapid aquifer restoration. The design model ensures that a contaminant plume is removed and treated within four years at the least possible cost. Rapid restoration is accomplished by maintaining...

Bed shear stress was estimated using wave and current measurements obtained with the GEOPROBE bottom-tripod system during resuspension events in Norton Sound, Alaska, and on the northern California shelf. The boundary-layer model of Grant and Madsen (1979, Journal of Geophysical Research, 84, 1797-1808) was used to compute the bed shear...

Although synthetic borehole seismograms can be computed for a wide range of borehole conditions, the physical nature of shear and compressional head waves in fluid-filled boreholes is poorly understood. This paper presents a series of numerical experiments designed to explain the physical mechanisms controlling head-wave propagation in boreholes. These calculations...

Modern wireline log combinations give highly diagnostic information that goes beyond the basic shale content, pore volume, and fluid saturation of older logs. Pattern recognition of geology from logs is made conventionally through either the examination of log overlays or log crossplots. Both methods can be combined through the use...

The feasibility of using the transient electromagnetic sounding (TS or TDEM) method for groundwater exploration can be studied by means of numerical models. As examples of its applicability to groundwater exploration, we study four groundwater exploration problems: (1) mapping of alluvial fill and gravel zones over bedrock; (2) mapping of...

Analysis of the sediment of Pecks Lake, Yavapai County, Arizona, has permitted the first reported palynological evidence for the historic expansion of juniper and desert shrubs in the American Southwest. The palynological evidence is supported by the comparison of modern and historical photographs, which shows the regional expansion of pinyon-juniper...

The origin of the Emperor-Hawaiian volcanic chain is attributed to the northwesterly movement of the Pacific plate over a stationary mantle plume (hotspot)1. There has been considerable controversy as to the nature and number of sources of Hawaiian hotspot volcanism. Thus far, most geochemical models have been based on rock...

Zimbabweite (Na,K)2PbAs4(Ta,Nb,Ti)4O18, a new mineral with trivalent arsenic, has been recognized at St Anns mine, southeast of Miami, Karoi district, Zimbabwe, in kaolinized pegmatite and dump material.The mineral is honey yellow-brown in large crystals, which are as much as 1 x 1 x 2 cm, and is clear pale yellow...

When analyzing the patterns of damage in an earthquake, physical parameters of the total earthquake-site-structure system are correlated with the damage. Soil-structure interaction, the cause of damage in many earthquakes, involves the frequency-dependent response of both the soil-rock column and the structure. The response of the soil-rock column (called site...