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David J. Grimes

Publications and source records attributed to David J. Grimes.

9 recordsLinked to original sources
USGS2008

Cyanide speciation at four gold leach operations undergoing remediation

Analyses have been made of 81 effluents from four gold leach operations in various stages of remediation to identify the most-persistent cyanide species. Total cyanide and weak acid-dissociable (WAD) cyanide were measured using improved methods, and metals known to form stable cyanocomplexes were also measured. Typically, total cyanide greatly exceeded WAD indicating that cyanide was predominantly in strong cyanometallic complexes. Iron was generally too low to accommodate the strongly complexed cyanide as Fe(CN) 6 3- or Fe(CN) 6 4- , but cobalt was abundant enough to implicate Co(CN) 6 3- or its dissociation products (Co(CN) 6-x (H 2 O) x (3-x)- ). Supporting evidence for cobalt-cyanide complexation was found in tight correlations between cobalt and cyanide in some sample suites. Also, abundant free cyanide was produced upon UV illumination. Iron and cobalt cyanocomplexes both photodissociate; however, the iron concentration was insufficient to have carried the liberated cyanide, while the cobalt concentration was sufficient. Cobalt cyanocomplexes have not previously been recognized in cyanidation wastes. Their identification at four separate operations, which had treated ores that were not especially rich in cobalt, suggests that cobalt complexation may be a common source of cyanide persistence. There is a need for more information on the importance and behavior of cobalt cyanocomplexes in ore-processing wastes at gold mines.

California;Nevada;New Mexico↗
USGS1998

Geochemical studies of rare earth elements in the Portuguese pyrite belt, and geologic and geochemical controls on gold distribution

This report describes geochemical and geological studies which were conducted by the U.S. Geological Survey (USGS) and the Servicos Geologicos de Portugal (SPG) in the Portuguese pyrite belt (PPB) in southern Portugal. The studies included rare earth element (REE) distributions and geological and geochemical controls on the distribution of gold. Rare earth element distributions were determined in representative samples of the volcanic rocks from five west-trending sub-belts of the PPB in order to test the usefulness of REE as a tool for the correlation of volcanic events, and to determine their mobility and application as hydrothermal tracers. REE distributions in felsic volcanic rocks show increases in the relative abundances of heavy REE and a decrease in La/Yb ratios from north to south in the Portuguese pyrite belt. Anomalous amounts of gold are distributed in and near massive and disseminated sulfide deposits in the PPB. Gold is closely associated with copper in the middle and lower parts of the deposits. Weakly anomalous concentrations of gold were noted in exhalative sedimentary rocks that are stratigraphically above massive sulfide deposits in a distal manganiferous facies, whereas anomalously low concentrations were detected in the barite-rich, proximal-facies exhalites. Altered and pyritic felsic volcanic rocks locally contain highly anomalous concentrations of gold, suggesting that disseminated sulfide deposits and the non-ore parts of massive sulfide deposits should be evaluated for their gold potential.

Professional Paper↗
USGS1985

Map showing abundance and distribution of copper in oxide residues of stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

Stream-sediment sampling in the Medford 1 o x 2 o quadrangle was undertaken to provide to aid in assessment of the mineral resource potential of the quadrangle. This map presents data on the abundance and distribution of copper in the oxide residues (oxalic-acid leachates) of stream sediments and in the minus-0.18-mm sieve fraction of selected stream sediments collected in the quadrangle.

Oregon↗
USGS1985

Map showing abundance and distribution of silver in stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

The Medford quadrangle is located in mountainous southwestern Oregon adjacent to the California border and a short distance east of the Pacific coast. Various parts of this area lie in different geologic provinces. Most of the western half of the quadrangle is underlain by pre-Tertiary rocks of the Klamath Mountains province. However, the Coast Range province is represented by the Tertiary sedimentary rocks in the northwest corner. Much of the eastern half of the quadrangle lies in the Cascade Range. In Oregon, because of differences in physiographic expression and age of rocks, this province is commonly divided into the more rugged High Cascade Range on the east and the more subdued Western Cascade Range on the west. This division is approximated on the map by the contact between the Quaternary and Tertiary volcanic rocks of the High Cascade Range and the Tertiary volcanic rocks of the Western Cascade Range. The geology shown is generalized from a more detailed compilation by Smith and others (1982).

Oregon↗
USGS1985

Map showing abundance and distribution of chromium in stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

The Medford quadrangle is located in mountainous southwestern Oregon adjacent to the California border and a short distance east of the Pacific coast. Various parts of this area lie in different geologic provinces. Most of the western half of the quadrangle is underlain by pre-Tertiary rocks of the Klamath Mountains province. However, the Coast Range province is represented by the Tertiary sedimentary rocks in the northwest corner. Much of the eastern half of the quadrangle lies in the Cascade Range. In Oregon, because of differences in physiographic expression and age of rocks, this province is commonly divided into the more rugged High Cascade Range on the east and the more subdued Western Cascade Range on the west. This division is approximated on the map by the contact between the Quaternary and Tertiary volcanic rocks of the High Cascade Range and the Tertiary volcanic rocks of the Western Cascade Range. The geology shown is generalized from a more detailed compilation by Smith and others (1982).

Oregon↗
USGS1985

Map showing abundance and distribution of arsenic in oxide residues of stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

Stream-sediment sampling in the Medford 1 o x 2 o quadrangle was undertaken to provide to aid in assessment of the mineral resource potential of the quadrangle. This map presents data on the abundance and distribution of copper in the oxide residues (oxalic-acid leachates) of stream sediments and in the minus-0.18-mm sieve fraction of selected stream sediments collected in the quadrangle.

Oregon↗
USGS1982

Map showing geochemical characteristics of rock samples from the Kalmiopsis Wilderness, southwestern Oregon

This report summarizes 1,307 semiquantitative chemical analyses of rocks collected to aid int he evaluation of the mineral resources of the Kalmiopsis Wilderness, Oreg. Chemical analyses and sample location maps are presented by Grimes, Leinz, and Speckman (1981). The area is located in the Kilamath Mountains geoporphic province of southwestern Oregon, and the area's location and boundaries are shown on the accompanying map. The geology of the study area is described by Page and others (1981), Gray (1980), and Ramp (1975). The rocks of the area cosist of dismembered ophiolite, island-arc, and sedimentary rock sequesnces that lie within the Western Jurassic belt of the Klamath Mountains. All units normally found within these assemblages are present; however, thrusting ans subsequent normal faulting have disrupted the geometric relations, producing a complexly faulted series of imbricate thrust slices.

Oregon↗
USGS1978

Spectrochemical determination of submicrogram amounts of tungsten in geologic materials

A rapid, sensitive, emission spectrographic method for the determination of tungsten in geologic materials has been developed. Sample fusion with potassium hydroxide followed by a hot-water leach renders the tungsten soluble. Acidification of the solution, reduction with titanium trichloride, complexing with thiocyanate, and ether extraction separate and concentrate the tungsten. An aliquot of the ether solution is pipetted into the cavity of a preformed graphite electrode containing 6 milligrams of sodium carbonate and is evaporated. The carbonate flux prevents formation of refractory tungsten carbide during arcing, resulting in nearly complete volatilization of tungsten during a short exposure period. Spectra from direct-current arc excitation of the tungsten are recorded on film and visually compared to standard spectra. A determination limit of 0.2-part-per-million tungsten is obtained from a 0.5-gram sample with a sample completion average of 30-50 samples per man-day.

Journal of Research of the U.S. Geological Survey↗