Magma chamber cooling by episodic volatile expulsion as constrained by mineral vein distributions in the Butte, Montana Cu-Mo porphyry deposit

NASA Astrophysics Data System (ADS)

Daly, K.; Karlstrom, L.; Reed, M. H.

2016-12-01

The role of hydrothermal systems in the thermal evolution of magma chambers is poorly constrained yet likely significant. We analyze trends in mineral composition, vein thickness and overall volumetric fluid flux of the Butte, Montana porphyry Cu-Mo deposit to constrain the role of episodic volatile discharge in the crystallization of the source magma chamber ( 300 km3of silicic magma). An aqueous fluid sourced from injection of porphyritic dikes formed the Butte porphyry Cu network of veins. At least three separate pulses of fluid through the system are defined by alteration envelopes of [1] gray sericite (GS); [2] early-dark micaceous (EDM), pale-green sericite (PGS), and dark-green sericite (DGS); and [3] quartz-molybdenite (Qmb) and barren-quartz. Previous research using geothermometers and geobarometers has found that vein mineral composition, inferred temperatures and inferred pressures vary systematically with depth. Later fluid pulses are characterized by lower temperatures, consistent with progressive cooling of the source. We have digitized previously unused structural data from Butte area drill cores, and applied thermomechanical modeling of fluid release from the source magma chamber through time. Vein number density and vein thickness increase with depth as a clear function of mineralogy and thus primary temperature and pressure. We identify structural trends in the three fluid pulses which seem to imply time evolution of average vein characteristics. Pulses of Qmb-barren quartz and EDM-PGS-DGS (1st and 2nd in time) exhibit increasing vein number density (157 & 95 veins/50m, respectively) and thickness (300mm & 120mm, respectively) as a function of depth. EDM-PGS-DGS has a shallower peak in vein density (800m) than Qmb-barren quartz (>1600m). These data provide the basis for idealized mechanical models of hydrofractures, to predict driving pressures and to compare with existing source temperatures and total fluid volumes in order to estimate the total

Cyclic development of igneous features and their relationship to high-temperature hydrothermal features in the Henderson porphyry molybdenum deposit, Colorado

USGS Publications Warehouse

Carten, R.B.; Geraghty, E.P.; Walker, B.M.

1988-01-01

The Henderson porphyry molybdenum deposit was formed by the superposition of coupled alteration and mineralization events, of varying intensity and size, that were associated with each of at least 11 intrusions. Deposition of molybdenite was accompanied by time-equivalent silicic and potassic alteration. High-temperature alteration and mineralization are spatially and temporally linked to the crystallization of compositionally zoned magma in the apex of stocks. Differences in hydrothermal features associated with each intrusion (e.g., mass of ore, orientation and type of veins, density of veins, and intensity of alteration) correlate with differences in primary igneous features (e.g., composition, texture, morphology, and size). The systematic relations between hydrothermal and magmatic features suggest that primary magma compositions, including volatile contents, largely control the geometry, volume, level of emplacement, and mechanisms of crystallization of stocks. These elements in turn govern the orientations and densities of fractures, which ultimately determine the distribution patterns of hydrothermal alteration and mineralization. -from Authors

The genesis of the Hashitu porphyry molybdenum deposit, Inner Mongolia, NE China: constraints from mineralogical, fluid inclusion, and multiple isotope (H, O, S, Mo, Pb) studies

NASA Astrophysics Data System (ADS)

Zhai, Degao; Liu, Jiajun; Tombros, Stylianos; Williams-Jones, Anthony E.

2018-03-01

The Hashitu porphyry molybdenum deposit is located in the Great Hinggan Range Cu-Mo-Pb-Zn-Ag polymetallic metallogenic province of NE China, in which the Mo-bearing quartz veins are hosted in approximately coeval granites and porphyries. The deposit contains more than 100 Mt of ore with an average grade of 0.13 wt.% Mo. This well-preserved magmatic-hydrothermal system provides an excellent opportunity to determine the source of the molybdenum, the evolution of the hydrothermal fluids and the controls on molybdenite precipitation in a potentially important but poorly understood metallogenic province. Studies of fluid inclusions hosted in quartz veins demonstrate that the Hashitu hydrothermal system evolved to progressively lower pressure and temperature. Mineralogical and fluid inclusion analyses and physicochemical calculations suggest that molybdenite deposition occurred at a temperature of 285 to 325 °C, a pressure from 80 to 230 bars, a pH from 3.5 to 5.6, and a Δlog fO2 (HM) of -3.0, respectively. Results of multiple isotope (O, H, S, Mo, and Pb) analyses are consistent in indicating a genetic relationship between the ore-forming fluids, metals, and the Mesozoic granitic magmatism (i.e., δ 18OH2O from +1.9 to +9.7‰, δDH2O from -106 to -87‰, δ 34SH2S from +0.3 to +3.9‰, δ 98/95Mo from 0 to +0.37‰, 206Pb/204Pb from 18.2579 to 18.8958, 207Pb/204Pb from 15.5384 to 15.5783, and 208Pb/204Pb from 38.0984 to 42.9744). Molybdenite deposition is interpreted to have occurred from a low-density magmatic-hydrothermal fluid in response to decreases in temperature, pressure, and fO2.

Geophysical model of the Cu-Mo porphyry ore deposit at Copper Flat Mine, Hillsboro, Sierra County, New Mexico

NASA Astrophysics Data System (ADS)

Gutierrez, Adrian Emmanuel Gutierrez

A 3D gravity model of the Copper Flat Mine was performed as part of the exploration of new resources in at the mine. The project is located in the Las Animas Mining District in Sierra County, New Mexico. The mine has been producing ore since 1877 and is currently owned by the New Mexico Copper Corporation, which plans o bringing the closed copper mine back into production with innovation and a sustainable approach to mining development. The Project is located on the Eastern side of the Arizona-Sonora-New Mexico porphyry copper Belt of Cretaceous age. Copper Flat is predominantly a Cretaceous age stratovolcano composed mostly of quartz monzonite. The quartz monzonite was intruded by a block of andesite alter which a series of latite dikes creating veining along the topography where the majority of the deposit. The Copper Flat deposit is mineralized along a breccia pipe where the breccia is the result of auto-brecciation due to the pore pressure. There have been a number of geophysical studies conducted at the site. The most recent survey was a gravity profile on the area. The purpose of the new study is the reinterpretation of the IP Survey and emphasizes the practical use of the gravity geophysical method in evaluating the validity of the previous survey results. The primary method used to identify the deposit is gravity in which four Talwani models were created in order to created a 3D model of the ore body. The Talwani models have numerical integration approaches that were used to divide every model into polygons. The profiles were sectioned into polygons; each polygon was assigning a specific density depending on the body being drawn. Three different gridding techniques with three different filtering methods were used producing ten maps prior to the modeling, these maps were created to establish the best map to fit the models. The calculation of the polygons used an exact formula instead of the numerical integration of the profile made with a Talwani approach. A

Mapping hydrothermal alteration using aircraft VNIR scanners at the Rosemont porphyry copper deposit. [Visible-Near Infrared

NASA Technical Reports Server (NTRS)

Sadowski, R. M.; Abrams, M. J.

1983-01-01

Two Visible-Near Infrared (VNIR) scanners, the NS-001 and the M2S, were flown over the Rosemont porphyry copper deposit as part of the NASA/JPL/GEOSAT test site program. This program was established to determine the feasibility and limitations of mapping hydrothermal alteration with multispectral scanners. Data from the NS-001 at 0.83 and 2.2 microns were used to identify Fe(3+) and OH enriched outcrops. These areas were then correlated with three alteration assemblages. The first correlation, hematite-epidote, was the most obvious and appeared as a strong ferric iron signature associated with hematite stained Cretaceous arkoses and andesites. The second correlation, qtz-sericite, showed a combined ferric-hydroxyl signature for a phyllicly altered quartz monzonite. The third correlation, skarn, was identified only after a review of calc-silicate mineral VNIR spectra. Altered limestones that outcrop west of the deposit have a similar ferric iron-hydroxyl signature as the quartz-sericite altered quartz monzonite. This skarn signature has been interpreted to indicate the presence of andradite, hydro-grossularite and idocrase. Data from the second scanner, M2S, was used to search for variation in ferric iron mineral type. Resulting imagery data indicated that hematite was the dominant ferric iron mineral present in the Rosemont area.

Uplift and submarine formation of some Melanesian porphyry copper deposits: Stable isotope evidence

USGS Publications Warehouse

Chivas, A.R.; O'Neil, J.R.; Katchan, G.

1984-01-01

Hydrogen and oxygen isotope analyses of sericites and kaolinites from four young porphyry copper deposits (Ok Tedi (1.2 Ma) and Yandera (6.5 Ma), Papua New Guinea; Koloula (1.5 Ma), Solomon Islands; and Waisoi (<5 Ma), Fiji) indicate that the fluids from which these minerals precipitated were of mixed magmatic and non-magmatic sources. The non-magmatic component of the fluid from the island arc deposits (Koloula, Waisoi) was ocean water. For Ok Tedi, the non-magmatic component was a meteoric water with an isotopic composition different from that of the present meteoric water in the region. The isotopic signature of the former meteoric water is consistent with a surface elevation of 200 m a.s.l. or less at the time of mineralization. The deposit was later exposed and supergene kaolinitization commenced at approximately 1200 m a.s.l. Uplift and erosion has continued to the present at which time the elevation of the exposed deposit is 1800 m a.s.l. This rate of uplift is consistent with that known from other geological evidence. If the rate of uplift were approximately constant during the last 1.2 Ma, the age of supergene enrichment can be dated at approximately 0.4 Ma B.P. Similarly, influx of meteoric water at Yandera occurred when the ground surface above the deposit was at an elevation of approximately 600 m a.s.l. The deposit's present elevation is 1600 m a.s.l. In this case a total uplift of approximately 2.2 km is indicated, with removal of 1.2 km of overburden by erosion. ?? 1984.

Comparison of U-spatial statistics and C-A fractal models for delineating anomaly patterns of porphyry-type Cu geochemical signatures in the Varzaghan district, NW Iran

NASA Astrophysics Data System (ADS)

Ghezelbash, Reza; Maghsoudi, Abbas

2018-05-01

The delineation of populations of stream sediment geochemical data is a crucial task in regional exploration surveys. In this contribution, uni-element stream sediment geochemical data of Cu, Au, Mo, and Bi have been subjected to two reliable anomaly-background separation methods, namely, the concentration-area (C-A) fractal and the U-spatial statistics methods to separate geochemical anomalies related to porphyry-type Cu mineralization in northwest Iran. The quantitative comparison of the delineated geochemical populations using the modified success-rate curves revealed the superiority of the U-spatial statistics method over the fractal model. Moreover, geochemical maps of investigated elements revealed strongly positive correlations between strong anomalies and Oligocene-Miocene intrusions in the study area. Therefore, follow-up exploration programs should focus on these areas.

Structural and numerical modeling of fluid flow and evolving stress fields at a transtensional stepover: A Miocene Andean porphyry copper system as a case study.

NASA Astrophysics Data System (ADS)

Nuñez, R. C.; Griffith, W. A.; Mitchell, T. M.; Marquardt, C.; Iturrieta, P. C.; Cembrano, J. M.

2017-12-01

Obliquely convergent subduction orogens show both margin-parallel and margin-oblique fault systems that are spatially and temporally associated with ore deposits and geothermal systems within the volcanic arc. Fault orientation and mechanical interaction among different fault systems influence the stress field in these arrangements, thus playing a first order control on the regional to local-scale fluid migration paths as documented by the spatial distribution of fault-vein arrays. Our selected case study is a Miocene porphyry copper-type system that crops out in the precordillera of the Maule region along the Teno river Valley (ca. 35°S). Several regional to local faults were recognized in the field: (1) Two first-order, N-striking subvertical dextral faults overlapping at a right stepover; (2) Second-order, N60°E-striking steeply-dipping, dextral-normal faults located at the stepover, and (3) N40°-60°W striking subvertical, sinistral faults crossing the stepover zone. The regional and local scale geology is characterized by volcano-sedimentary rocks (Upper Eocene- Lower Miocene), intruded by Miocene granodioritic plutons (U-Pb zircon age of 18.2 ± 0.11 Ma) and coeval dikes. We implement a 2D boundary element displacement discontinuity method (BEM) model to test the mechanical feasibility of kinematic model of the structural development of the porphyry copper-type system in the stepover between N-striking faults. The model yields the stress field within the stepover region and shows slip and potential opening distribution along the N-striking master faults under a regionally imposed stress field. The model shows that σ1 rotates clockwise where the main faults approach each other, becoming EW when they overlap. This, in turn leads to the generation of both NE- and NW-striking faults within the stepover area. Model results are consistent with the structural and kinematic data collected in the field attesting for enhanced permeability and fluid flow transport

Petrogenesis of the late Early Cretaceous granodiorite - Quartz diorite from eastern Guangdong, SE China: Implications for tectono-magmatic evolution and porphyry Cu-Au-Mo mineralization

NASA Astrophysics Data System (ADS)

Jia, Lihui; Mao, Jingwen; Liu, Peng; Li, Yang

2018-04-01

Comprehensive petrological, zircon U-Pb dating, Hf-O isotopes, whole rock geochemistry and Sr-Nd isotopes data are presented for the Xinwei and Sanrao intrusions in the eastern Guangdong Province, Southeast (SE) China, with an aim to constrain the petrogenesis, tectono-magmatic evolution and evaluate the implication for porphyry Cu-Au-Mo mineralization. The Xinwei intrusion is composed of granodiorite and quartz diorite, whilst the Sanrao intrusion consists of granodiorite. Zircon U-Pb ages show that both intrusions were emplaced at ca. 106-102 Ma. All rocks are metaluminous to weakly peraluminous, high-K calc-alkaline in composition, and they are characterized by LREEs enrichment, depletion in Nb, Ta, P, and Ti, and strongly fractionated LREEs to HREEs. The initial 87Sr/86Sr ratios range from 0.7055 to 0.7059, and εNd(t) values range from -3.9 to -3.0. Together with the relatively high εHf(t) values (-3.2 to 3.3) and low δ18O values (4.9‰ to 6.6‰), these data suggest that the Xinwei and Sanrao intrusions were derived from a mixed source: including the mantle-derived mafic magmas and lower continental crustal magmas. Fractional crystallization played an important role in the magmatic evolution of the Xinwei and Sanrao intrusions. The elemental and isotopic compositions of the Xinwei and Sanrao intrusions, as well as the high water content and oxidation state of their parental magmas, are similar to those of the ore-bearing granodiorites of the Luoboling porphyry Cu-Mo deposit in the Fujian Province, neighbouring east to the Guangdong Province, indicating that the late Early Cretaceous granodioritic intrusions in the eastern Guangdong Province may also have Cu-Au-Mo mineralization potential. The late Early Cretaceous magmatic event is firstly reported in eastern Guangdong, and represents a positive response of large-scale lithosphere extension and thinning, triggered by the changing subduction direction of the Paleo-Pacific plate from oblique subduction to

Structural setting of Fimiston- and Oroya-style pyrite-telluride-gold lodes, Paringa South mine, Golden Mile, Kalgoorlie: 1. Shear zone systems, porphyry dykes and deposit-scale alteration zones

NASA Astrophysics Data System (ADS)

Mueller, Andreas G.

2017-07-01

The Golden Mile in the 2.7 Ga Eastern Goldfields Province of the Yilgarn Craton, Western Australia, has produced 385 million tonnes of ore at a head grade of 5.23 g/t gold (1893-2016). Gold-pyrite ore bodies (Fimiston Lodes) trace kilometre-scale shear zone systems centred on the D2 Golden Mile Fault, one of three northwest striking sinistral strike-slip faults segmenting upright D1 folds. The Fimiston shear zones formed as D2a Riedel systems in greenschist-facies (actinolite-albite) tholeiitic rocks, the 700-m-thick Golden Mile Dolerite (GMD) sill and the Paringa Basalt (PB), during left-lateral displacement of up to 12 km on the D2 master faults. Pre-mineralisation granodiorite dykes were emplaced into the D2 shear zones at 2674 ± 6 Ma, and syn-mineralisation diorite porphyries at 2663 ± 11 Ma. The widespread infiltration of hydrothermal fluid generated chlorite-calcite and muscovite-ankerite alteration in the Golden Mile, and paragonite-ankerite-chloritoid alteration southeast of the deposit. Fluid infiltration reactivated the D2 shear zones causing post-porphyry displacement of up to 30 m at principal Fimiston Lodes moving the southwest block down and southeast along lines pitching 20°SE. D3 reverse faulting at the southwest dipping GMD-PB contact of the D1 Kalgoorlie Anticline formed the 1.3-km-long Oroya Shoot during late gold-telluride mineralisation. Syn-mineralisation D3a reverse faulting alternated with periods of sinistral strike-slip (D2c) until ENE-WSW shortening prevailed and was accommodated by barren D3b thrusts. North-striking D4 strike-slip faults of up to 2 km dextral displacement crosscut the Fimiston Lodes and the barren thrusts, and control gold-pyrite quartz vein ore at Mt. Charlotte (2651 ± 9 Ma).

Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico

USGS Publications Warehouse

Verplanck, P.L.; Nordstrom, D. Kirk; Bove, D.J.; Plumlee, G.S.; Runkel, R.L.

2009-01-01

Acidic, metal-rich waters produced by the oxidative weathering and resulting leaching of major and trace elements from pyritic rocks can adversely affect water quality in receiving streams and riparian ecosystems. Five study areas in the southern Rocky Mountains with naturally acidic waters associated with porphyry mineralization were studied to document variations in water chemistry and processes that control the chemical variations. Study areas include the Upper Animas River watershed, East Alpine Gulch, Mount Emmons, and Handcart Gulch in Colorado and the Red River in New Mexico. Although host-rock lithologies in all these areas range from Precambrian gneisses to Cretaceous sedimentary units to Tertiary volcanic complexes, the mineralization is Tertiary in age and associated with intermediate to felsic composition, porphyritic plutons. Pyrite is ubiquitous, ranging from ???1 to >5 vol.%. Springs and headwater streams have pH values as low as 2.6, SO4 up to 3700 mg/L and high dissolved metal concentrations (for example: Fe up to 400 mg/L; Cu up to 3.5 mg/L; and Zn up to 14.4 mg/L). Intensity of hydrothermal alteration and presence of sulfides are the primary controls of water chemistry of these naturally acidic waters. Subbasins underlain by intensely hydrothermally altered lithologies are poorly vegetated and quite susceptible to storm-induced surface runoff. Within the Red River study area, results from a storm runoff study documented downstream changes in river chemistry: pH decreased from 7.80 to 4.83, alkalinity decreased from 49.4 to <1 mg/L, SO4 increased from 162 to 314 mg/L, dissolved Fe increased from to 0.011 to 0.596 mg/L, and dissolved Zn increased from 0.056 to 0.607 mg/L. Compared to mine drainage in the same study areas, the chemistry of naturally acidic waters tends to overlap but not reach the extreme concentrations of metals and acidity as some mine waters. The chemistry of waters draining these mineralized but unmined areas can be used to

Temporal and spatial distribution of alteration, mineralization and fluid inclusions in the transitional high-sulfidation epithermal-porphyry copper system at Red Mountain, Arizona

USGS Publications Warehouse

Lecumberri-Sanchez, Pilar; Newton, M. Claiborne; Westman, Erik C.; Kamilli, Robert J.; Canby, Vertrees M.; Bodnar, Robert J.

2013-01-01

Red Mountain, Arizona, is a Laramide porphyry Cu system (PCD) that has experienced only a modest level of erosion compared to most other similar deposits in the southwestern United States. As a result, the upper portion of the magmatic–hydrothermal system, which represents the transition from shallower high-sulfidation epithermal mineralization to deeper porphyry Cu mineralization, is well preserved. Within the Red Mountain system, alteration, mineralization and fluid inclusion assemblages show a systematic distribution in both time and space. Early-potassic alteration (characterized by the minerals biotite and magnetite) is paragenetically earlier than late-potassic alteration (K-feldspar–anhydrite) and both are followed by later phyllic (sericite–pyrite) alteration. Advanced argillic alteration (pyrophyllite–alunite–other clay minerals) is thought to be coeval with or postdate phyllic alteration. Minerals characteristic of advanced argillic alteration are present in the near surface. Phyllic alteration extends to greater depths compared to advanced argillic alteration. Early-potassic and late-potassic alteration are only observed in the deepest part of the system. Considerable overlap of phyllic alteration with both early-potassic and late-potassic alteration zones is observed. The hypogene mineralization contains 0.4–1.2% Cu and is spatially and temporally related to the late-potassic alteration event. Molybdenum concentration is typically In the deepest part of the system, an early generation of low-to-moderate density and salinity liquid + vapor inclusions with opaque daughter minerals is followed in time by halite-bearing inclusions that also contain opaque daughter minerals indicating that an early intermediate-density magmatic fluid evolved to a high-density, high-salinity mineralizing fluid. The increase in density and salinity of fluids with time observed in the deeper parts of the system may be the result of immiscibility (“boiling”) of

Low molecular weight carboxylic acids in oxidizing porphyry copper tailings.

PubMed

Dold, Bernhard; Blowes, David W; Dickhout, Ralph; Spangenberg, Jorge E; Pfeifer, Hans-Rudolf

2005-04-15

The distribution of low molecular weight carboxylic acids (LMWCA) was investigated in pore water profiles from two porphyry copper tailings impoundments in Chile (Piuquenes at La Andina and Cauquenes at El Teniente mine). The objectives of this study were (1) to determine the distribution of LMWCA, which are interpreted to be the metabolic byproducts of the autotroph microbial community in this low organic carbon system, and (2) to infer the potential role of these acids in cycling of Fe and other elements in the tailings impoundments. The speciation and mobility of iron, and potential for the release of H+ via hydrolysis of the ferric iron, are key factors in the formation of acid mine drainage in sulfidic mine wastes. In the low-pH oxidation zone of the Piuquenes tailings, Fe(III) is the dominant iron species and shows high mobility. LMWCA, which occur mainly between the oxidation front down to 300 cm below the tailings surface at both locations (e.g., max concentrations of 0.12 mmol/L formate, 0.17 mmol/L acetate, and 0.01 mmol/L pyruvate at Piuquenes and 0.14 mmol/L formate, 0.14 mmol/L acetate, and 0.006 mmol/L pyruvate at Cauquenes), are observed at the same location as high Fe concentrations (up to 71.2 mmol/L Fe(II) and 16.1 mmol/L Fe(III), respectively). In this zone, secondary Fe(III) hydroxides are depleted. Our data suggest that LMWCA may influence the mobility of iron in two ways. First, complexation of Fe(III), through formation of bidentate Fe(III)-LMWCA complexes (e.g., pyruvate, oxalate), may enhance the dissolution of Fe(III) (oxy)hydroxides or may prevent precipitation of Fe(III) (oxy)hydroxides. Soluble Fe(III) chelate complexes which may be mobilized downward and convert to Fe(II) by Fe(III) reducing bacteria. Second, monodentate LMWCA (e.g., acetate and formate) can be used by iron-reducing bacteria as electron donors (e.g., Acidophilum spp.), with ferric iron as the electron acceptor. These processes may, in part, explain the low abundances

Distribution and composition of gold in porphyry gold systems: example from the Biely Vrch deposit, Slovakia

NASA Astrophysics Data System (ADS)

Koděra, Peter; Kozák, Jaroslav; Brčeková, Jana; Chovan, Martin; Lexa, Jaroslav; Jánošík, Michal; Biroň, Adrián; Uhlík, Peter; Bakos, František

2018-03-01

The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K- and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold ( 914), whereas Ca-Na silicate alteration has the highest ( 983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness ( 994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309 °C, mostly during retrograde quartz solubility.

Alteration Mineralogy and Geochemical Characteristics of Porphyry Cu-Mo Mineralization in Domaniç (Kütahya) Area

NASA Astrophysics Data System (ADS)

Sariiz, K.; Sendir, H.

2012-04-01

The study area is located at 30 km northwest of Domaniç (Kütahya) and covers on approximately 250 square kilometers. The Devonian (Paleozoic) schists which are composed of gneiss, mica schist and chlorite schist is the oldest unit of the study area. This units are overlain unconformably by the Permian Allıkaya Marbles. Eocene granodioritic intrusives cut other rock series and located as a batholite. Magmatic units present porphyric and holocrystalline textures. Granodioritic intrusions are represented by tonalite, tonalite porphyr, granodiorite, granodiorite porphyr, granite, diorite, diorite porphyries. Potassic, phyllitic and prophyllitic hydrothermal alteration zones are determined in host rocks and wallrocks. Mineralizations are observed as disseminated, and stockwork types within the granodioritic rocks. Ore minerals are pyrotine, pyrite, chalcopyrite, molybdenite, rutile, bornite, sphalerite, marcasite and limonite. Geochemically, it is of sub-alkaline affinity, belongs to the high-K, calc-alkaline series and displays features of typical I-type affinity. They show enrichment in large-ion lithophile elements (LIL) and depletion Nb and Ti indicating a subduction zone related magmatic signature for their origin. δ18O (quartz) values range from 8,8 to 12,1 ‰. δ18O (biotite) and δD (biotite) values range from 2,6 to 6,1 ‰ and -87 - -125 (SMOW). These values indicate that mixture magmatic-meteoric of hydrothermal solutions origin which are potassic to propylitic zones. δ13C (calcite) values range from 1,9 to 3,3 ‰ (PDB). Calcite values within the marine carbonates in the study area.

Geophysical and geochemical data from the area of the Pebble Cu-Au-Mo porphyry deposit, southwestern Alaska: Contributions to assessment techniques for concealed mineral resources

USGS Publications Warehouse

Anderson, E.D.; Smith, S.M.; Giles, S.A.; Granitto, Matthew; Eppinger, R.G.; Bedrosian, P.A.; Shah, A.K.; Kelley, K.D.; Fey, D.L.; Minsley, B.J.; Brown, P.J.

2011-01-01

In 2007, the U.S. Geological Survey began a multidisciplinary study in southwest Alaska to investigate the setting and detectability of mineral deposits in concealed volcanic and glacial terranes. The study area hosts the world-class Pebble porphyry Cu-Au-Mo deposit, and through collaboration with the Pebble Limited Partnership, a range of geophysical and geochemical investigations was carried out in proximity to the deposit. The deposit is almost entirely concealed by tundra, glacial deposits, and post-mineralization volcanic rocks. The discovery of mineral resources beneath cover is becoming more important because most of the mineral resources at the surface have already been discovered. Research is needed to identify ways in which to assess for concealed mineral resources. This report presents the uninterpreted geophysical measurements and geochemical and mineralogical analytical data from samples collected during the summer field seasons from 2007 to 2010, and makes the data available in a single Geographic Information System (GIS) database.

3D inversion of SPECTREM and ZTEM airborne electromagnetic data from the Pebble Cu-Au-Mo porphyry deposit, Alaska

NASA Astrophysics Data System (ADS)

Pare, Pascal; Gribenko, Alexander V.; Cox, Leif H.; Čuma, Martin; Wilson, Glenn A.; Zhdanov, Michael S.; Legault, Jean; Smit, Jaco; Polome, Louis

2012-04-01

Geological, geochemical, and geophysical surveys have been conducted in the area of the Pebble Cu-Au-Mo porphyry deposit in south-west Alaska since 1985. This case study compares three-dimensional (3D) inversion results from Anglo American's proprietary SPECTREM 2000 fixed-wing time-domain airborne electromagnetic (AEM) and Geotech's ZTEM airborne audio-frequency magnetics (AFMAG) systems flown over the Pebble deposit. Within the commonality of their physics, 3D inversions of both SPECTREM and ZTEM recover conductivity models consistent with each other and the known geology. Both 3D inversions recover conductors coincident with alteration associated with both Pebble East and Pebble West. The high grade CuEqn 0.6% ore shell is not consistently following the high conductive trend, suggesting that the SPECTREM and ZTEM responses correspond in part to the sulphide distribution, but not directly with the ore mineralization. As in any exploration project, interpretation of both surveys has yielded an improved understanding of the geology, alteration and mineralization of the Pebble system and this will serve well for on-going exploration activities. There are distinct practical advantages to the use of both SPECTREM and ZTEM, so we draw no recommendation for either system. We can conclude however, that 3D inversion of both AEM and ZTEM surveys is now a practical consideration and that it has added value to exploration at Pebble.

In situ major and trace element analysis of amphiboles in quartz monzodiorite porphyry from the Tonglvshan Cu-Fe (Au) deposit, Hubei Province, China: insights into magma evolution and related mineralization

NASA Astrophysics Data System (ADS)

Duan, Deng-Fei; Jiang, Shao-Yong

2017-05-01

The Tonglvshan deposit is the largest Cu-Fe (Au) skarn deposit in the Edong district, which is located in the westernmost part of the Middle and Lower Yangtze River metallogenic belt, China. In this study, we performed a detailed in situ analysis of major and trace elements in amphiboles from the ore-related Tonglvshan quartz monzodiorite porphyry using electron microprobe (EMPA) analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Two distinct populations of amphiboles, which can be distinguished by their aluminum content, are found in the quartz monzodiorite porphyry. The low-aluminum (Low-Al) amphiboles are subhedral or anhedral and formed at 46.3-73.5 MPa and 713-763 °C. In contrast, the high-aluminum (High-Al) amphiboles are euhedral and formed at 88-165 MPa and 778-854 °C. Some euhedral amphiboles are partially or completely replaced by Low-Al amphibole. The compositions of parental melts in equilibrium with the High-Al amphibole ( Melt 1) and Low-Al amphibole ( Melt 2) were computed by applying solid/liquid partition coefficients. This modeling shows that magma in equilibrium with High-Al amphibole ( Melt 1) underwent 40% fractional crystallization of amphibole, plagioclase and apatite at a depth of 5 km to evolve to magma in equilibrium with Low-Al amphibole ( Melt 2). Copper enrichment occurred in the magma after undergoing fractional crystallization. The magma had a high oxygen fugacity, increasing from NNO + 1 ( Melt 1) through NNO + 2 to HM ( Melt 2), which could have prevented the loss of Cu (and possibly Au) to sulfide minerals during crystallization. Finally, the evolved magma intruded to shallower depths, where it presumably exsolved aqueous ore-forming fluids. Therefore, the large Cu-Fe-Au reserves of the Tonglvshan deposit can likely be attributed to a combination of controlling factors, including high oxygen fugacity, fractional crystallization, fluid exsolution, and a shallow emplacement depth.

Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

USGS Publications Warehouse

Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

1990-01-01

Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

Mining Operations.

DTIC Science & Technology

1984-09-12

hardness; (15) very hard granite rocks. Quartz- porphyry , very hard granite, flinty slate, and quartzite that are less hard than the above. Hardest...7) quartzites in general; (8) basalts in general;(9) Volyn basalt; (10) porphuries in general; (11) Gohland porphyry ; (12) very hard granite; (13...57) Tethmayer; (58) new edition; (59) Gus’kov; (60) old edition; (61) hard quartzite; (62) hard basalt; (63) very hard porphyry ; (64) porphyry in

Carboniferous-Permian tectonic transition envisaged in two magmatic episodes at the Kuruer Cu-Au deposit, Western Tianshan (NW China)

NASA Astrophysics Data System (ADS)

Yu, Jie; Li, Nuo; Qi, Nan; Guo, Jian-Ping; Chen, Yan-Jing

2018-03-01

The Western Tianshan in NW China is one of the most important gold provinces in the Central Asian Orogenic Belt (CAOB). The recently discovered Kuruer Cu-Au deposit has been interpreted to represent a transition from high-sulfidation epithermal to porphyry mineralization system. In this study, we present new LA-ICP-MS zircon U-Pb ages for the many magmatic rock types at Kuruer, including the Dahalajunshan Formation andesitic tuff (333.2 ± 1.6 Ma), diorite porphyry (269.7 ± 2.0 Ma), slightly-altered (264.4 ± 2.6 Ma) and intensively-altered (270.5 ± 2.5 Ma) albite porphyry. These ages reveal two distinct magmatic episodes: The Early Carboniferous Dahalajunshan Formation (wall rocks) andesitic tuff samples contain narrow ranges of SiO2 (60.29-61.28 wt.%), TiO2 (0.96-0.98 wt.%), Al2O3 (16.55-16.57 wt.%) and Fe2O3T (5.36-5.57 wt.%). The tuff is characterized by LREE enrichment and HFSE depletion, as well as LREE/HREE enrichment ((La/Yb)N = 8.31-8.76) and negative Eu anomalies (δEu = 0.64-0.76). Zircon εHf (t) values are 5.4-8.2, and two-stage Hf model ages (TDM2) are 821-1016 Ma, indicating partial melting of a moderately depleted mantle wedge with Precambrian continental crustal input. The ore-forming Middle Permian diorite porphyry and (quartz) albite porphyry have variable major oxide compositions (e.g., SiO2 = 53.09-53.12 wt.% for the diorite porphyry, 70.84-78.03 wt.% for the albite porphyry, and 74.07-75.03 wt.% for the quartz albite porphyry) but similar chondrite-normalized REE and primitive mantle-normalized multi-element patterns. These porphyries display LREE enrichment and HFSE depletion, as well as elevated LREE/HREE enrichment and negative Eu anomalies. The positive zircon εHf(t) values (11.7-15.9 for the diorite porphyry, 8.9-14.9 for the albite porphyry) and young two-stage Hf model ages (TDM2) (282-542 Ma for the diorite porphyry, 337-717 Ma for the albite porphyry) indicate a major juvenile continental crustal involvement. We propose that the

Typomorphic Characteristics of Molybdenite from the Bystrinsky Cu-Au Porphyry-Skarn Deposit, Eastern Transbaikal Region, Russia

NASA Astrophysics Data System (ADS)

Kovalenker, V. A.; Trubkin, N. V.; Abramova, V. D.; Plotinskaya, O. Yu.; Kiseleva, G. D.; Borisovskii, S. E.; Yazykova, Yu. I.

2018-01-01

The paper presents pioneering data on the composition, texture, and crystal structure of molybdenite from various types of molybdenum mineralization at the Bystrinsky Cu-Au-Fe porphyry-skarn deposit in the eastern Transbaikal region, Russia. The data were obtained using electron microprobe analysis (EMPA), laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), and high-resolution transmission electron microscopy (HRTEM). Molybdenite found at the deposit in skarn, sulfide-poor quartz veins, and quartz-feldspar alteration markedly differs in the concentrations of trace elements determined by their species in the mineral, as well as in its structural features. Molybdenite-2H from skarn associated with phyllosilicates occurs as ultrafine crystals with uniform shape and texture; no dislocations or inclusions were found but amorphous silica was. The molybdenite composition is highly contrasting in the content and distribution of both structure-related (Re, W, and Se) and other (Mn, Co, Ni, Cu, Zn, As, Ag, Cd, Sb, Te, Ag, Pd, Au, Hg, Pb, and Bi) metals. In the sulfide-poor quartz veins, highly structurally heterogeneous (2H + 3R) molybdenite microcrystals with abundant defects (dislocations and volumetrically distributed inclusions) are associated with illite, goethite, and barite. Some single crystals are unique three-phase (2H + 3R polytypes + amorphous MoS2). The mineral has a low concentration of all trace elements, which are uniformly distributed. However, individual domains with uniquely high Pd, Te, Ni, Hg, and W concentrations caused by mineral inclusions are found in some grains. Molybdenite from quartz-feldspar alteration is characterized by low concentrations of all trace elements except for Re and Se, which enrich some domains of the grains. Our data indicate that the compositional and structural heterogeneity of molybdenite from the Bystrinsky deposit are its crucial features, which obviously correlate with the types of Mo mineralization.

A Study of Knowledge-Based Systems for Photo Interpretation.

DTIC Science & Technology

1980-06-01

special models have been developed by V. F. Hollister and A. N. Campbell to aid in the selection of drilling targets for porphyry copper and...type lead/zinc N. Campbell 20 Kuroko-type massive sulfide C. F. Park, Jr. 34 Komatiitic-type nickel sulfide A. J. Naldrett 72 Butte-type porphyry copper ...M. T. Einaudi 104 Yerington-type porphyry copper M. T. Einaudi 143 Island-arc-type porphyry copper D. Cox 116 Roll-front sandstone uranium R. I

Ultra-deep oxidation and exotic copper formation at the late pliocene boyongan and bayugo porphyry copper-gold deposits, surigao, philippines: Geology, mineralogy, paleoaltimetry, and their implications for Geologic, physiographic, and tectonic controls

USGS Publications Warehouse

Braxton, D.P.; Cooke, D.R.; Ignacio, A.M.; Rye, R.O.; Waters, P.J.

2009-01-01

The Boyongan and Bayugo porphyry copper-gold deposits are part of an emerging belt of intrusion-centered gold-rich deposits in the Surigao district of northeast Mindanao, Philippines. Exhumation and weathering of these Late Pliocene-age deposits has led to the development of the world's deepest known porphyry oxidation profile at Boyongan (600 m), and yet only a modest (30-70 m) oxidation profile at adjacent Bayugo. Debris flows, volcanic rocks, and fluviolacustrine sediments accumulating in the actively extending Mainit graben subsequently covered the deposits and preserved the supergene profiles. At Boyongan and Bayugo, there is a vertical transition from shallower supergene copper oxide minerals (malachite + azurite + cuprite) to deeper sulfide-stable assemblages (chalcocite ?? hypogene sulfides). This transition provides a time-integrated proxy for the position of the water table at the base of the saturated zone during supergene oxidation. Contours of the elevation of the paleopotentiometric surface based on this min- eralogical transition show that the thickest portions of the unsaturated zone coincided with a silt-sand matrix diatreme breccia complex at Boyongan. Within the breccia complex, the thickness of the unsaturated zone approached 600 in, whereas outside the breccia complex (e.g., at Bayugo), the thickness averaged 50 m. Contours of the paleopotentiometric surface suggest that during weathering, groundwater flowed into the breccia complex from the north, south, and east, and exited along a high permeability zone to the west. The high relief (>550 m) on the elevation of the paleopotentiometric surface is consistent with an environment of high topographic relief, and the outflow zone to the west of the breccia complex probably reflects proximity to a steep scarp intersecting the western breccia complex margin. Stable isotope paleoaltimetry has enabled estimation of the elevation of the land surface, which further constrains the physiographic setting

Preliminary Geothermal Exploration at the Marine Corps Air Ground Combat Center, Twentynine Palms, California

DTIC Science & Technology

1987-09-01

porphyries with olivine phenocrysts. Individual flows may be about 50 feet thick around Pisgah Crater but taper out to a few feet thick at the flow’s...Pleistocene in age (Dibblee, 1966b). SUNSHINE PEAK The dominant rock of Sunshine Peak is dacite porphyry , a gray-white to light greenish- gray rock, with 40...northwest-trending andesite porphyry dikes. 14 ’-WC TP 6747 Roof pendants of biotite quartz monzonite and quartz monzonite occur in the dacite porphyry . The

Sequential extraction techniques applied to a porphyry copper deposit in the basin and range province

USGS Publications Warehouse

Filipek, L.H.; Theobald, P.K.

1981-01-01

Samples of minus-80-mesh (<180 ??m) stream sediment, rock containing exposed fracture coatings, and jarosite and chrysocolla were collected from an area surrounding the North Silver Bell porphyry Cu deposit near Tucson, Arizona. The samples were subjected to a series of extractions in a scheme originally designed for use on samples from humid or sub-humid environments, in which the following fractions can effectively be separated: (1) carbonates and exchangeable metals; (2) Mn oxides; (3) organic compounds and sulfides; (4) hydrous Fe oxides; and (5) residual crystalline minerals. Jarosite and chrysocolla, two major minerals of the North Silver Bell area, were found to dissolve over two or more steps of the extraction scheme. The results represent only a limited number of samples from one copper deposit. Nevertheless, they do suggest that in a semiarid to arid environment, where mechanical dispersion of such minerals predominates, uncritical assignment of unique phases, such as Mn oxides or organics to a given extraction would lead to false interpretations of weathering processes. However, the relative proportions of elements dissolved in each step of the jarosite and chrysocolla extractions could be used as a "fingerprint" for recognition of the presence of these two minerals in the stream-sediment and rock samples. The relative abundance of hydrous Fe oxide and jarosite and the alteration zoning could be mapped using data from jarosite and chrysocolla extractions. Manganese oxides were also found to have a greater influence on Zn than on Cu or Pb during supergene alteration. The rapid change in relative importance of the first (1M-acetic acid) extraction for Cu, Zn, and Pb near the mineralized zone suggested the occurrence of minor hydromorphic processes within the stream sediments. Thus, the acetic acid extraction proved the most effective for pinpointing mineralization in sediments. In contrast, the residual fraction had the longest dispersion train, suggesting

A conceptual model of the copper-porphyry ore formation based on joint analysis of deep 3D geophysical models: Sorskoe complex (Russia) case study

NASA Astrophysics Data System (ADS)

Spichak, Viacheslav V.; Goidina, Alexandra G.

2017-12-01

Joint analysis of deep three-dimensional models of the electrical resistivity, seismic velocity, and density of the complex hosting the Sorskoe Cu-Mo deposit (Russia) is carried out aimed at finding geophysical markers characterizing the areas of ore generation, transportation and deposition. The three-dimensional lithology model of the study area is built based on the empirical relationship between the silica content of the rocks and seismic velocities. It is in agreement with geological and geochemical studies provided in this area earlier and could be used as a basis for forecasting locations of the copper-molybdenum ore deposits at depth. A conceptual model of the copper-porphyry complex explaining the mechanisms of ore generation, transportation from the lower to the upper crust and deposition in the upper crust is suggested. In particular, it is supposed that post-magmatic supercritical gas-water ore-bearing fluids are upwelling through the plastic crust due to the sliding of the fluid films along the cleavage planes of the foliated rocks while at the depths of the brittle upper crust this mechanism could be changed by volumetric fluid transportation along the network of large pores and cracks.

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia.

PubMed

Mohamed Johar, S; Embong, Z

2015-11-01

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Occurrence of Giardia and Cryptosporidium (oo)cysts in the river water of two recreational areas in Selangor, Malaysia.

PubMed

Azman, J; Init, I; Wan Yusoff, W S

2009-12-01

This study is the first report on the occurrence of Giardia and Cryptosporidium (oo)cysts in recreational rivers water from Malaysia. It was carried out in water samples at two rivers, 'Sungai Congkak' and 'Sungai Batu', located in Selangor State. The occurrence of both Giardia lamblia and Cryptosporidium parvum (oo)cysts was higher in Sungai Congkak (50% or 15/30 and 10% or 3/30 respectively) than Sungai Batu (16% or 5/30 and 3.3% or 1/30 respectively). The mean density of cysts/L was 0.72 in Sungai Congkak and 0.023 in Sungai Batu, and that of oocysts/L was 0.023 in Sungai Congkak and 0.0033 in Sungai Batu, showing that the occurrence of Giardia was higher and more frequent than Cryptosporidium in both rivers. Sungai Congkak also showed higher faecal coliforms count (ranging from 0.48x10³ to 73x10³ CFU/100 mL) than Sungai Batu (0.41x10³ to 16x10³ CFU/100 mL). On the other hand, the Giardia and Cryptosporidium (oo)cysts and faecal coliforms were more concentrated at the downstream station, followed by midstream and upstream stations which might be due to human factors where settlements and recreation areas were located around and between midstream and downstream stations. The (oo)cysts and faecal coliforms also increased during public holidays due to the significantly higher number of visitors (bathers) compared with the week days. All the parameters (physical, faecal coliforms and rainfall) did not show consistent significant correlation (based on r values of Pearson correlation analysis) with both protozoa, therefore these parameters are not suitable as indicator for the presence of Giardia and Cryptosporidium (oo)cysts in both rivers.

The partitioning of copper among selected phases of geologic media of two porphyry copper districts, Puerto Rico

USGS Publications Warehouse

Learned, R.E.; Chao, T.T.; Sanzolone, R.F.

1981-01-01

In experiments designed to determine the manner in which copper is partitioned among selected phases that constitute geologic media, we have applied the five-step sequential extraction procedure of Chao and Theobald to the analysis of drill core, soils, and stream sediments of the Rio Vivi and Rio Tanama porphyry copper districts of Puerto Rico. The extraction procedure affords a convenient means of determining the trace-metal content of the following fractions: (1) Mn oxides and "reactive" Fe oxides; (2) "amorphous" Fe oxides; (3) "crystalline" Fe oxides; (4) sulfides and magnetite; and (5) silicates. An additional extraction between steps (1) and (2) was performed to determine organic-related copper in stream sediments. The experimental results indicate that apportionment of copper among phases constituting geologic media is a function of geochemical environment. Distinctive partitioning patterns were derived from the analysis of drill core from each of three geochemical zones: (a) the supergene zone of oxidation; (b) the supergene zone of enrichment; and (c) the hypogene zone; and similarly, from the analysis of; (d) soils on a weakly leached capping; (e) soils on a strongly leached capping; and (f) active stream sediment. The experimental results also show that geochemical contrasts (anomaly-to-background ratios) vary widely among the five fractions of each sampling medium investigated, and that at least one fraction of each medium provides substantially stronger contrast than does the bulk medium. Fraction (1) provides optimal contrast for stream sediments of the district; fraction (2) provides optimal contrast for soils on a weakly leached capping; fraction (3) provides optimal contrast for soils on a strongly leached capping. Selective extraction procedures appear to have important applications to the orientation and interpretive stages of geochemical exploration. Further investigation and testing of a similar nature are recommended. ?? 1981.

Bioleaching of two different types of chalcopyrite by Acidithiobacillus ferrooxidans

NASA Astrophysics Data System (ADS)

Dong, Ying-bo; Lin, Hai; Fu, Kai-bin; Xu, Xiao-fang; Zhou, Shan-shan

2013-02-01

Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with Acidithiobacillus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is quite different. The copper extraction reaches 46.96% for the pyritic chalcopyrite after 48-d leaching, but it is only 14.50% for the porphyry chalcopyrite. Proper amounts of initial ferrous ions can improve the efficiency of copper extraction for the two different types of chalcopyrite. The optimum dosage of ferrous ions for the pyritic chalcopyrite and porphyry chalcopyrite is different. The adsorption of ATF6 on the pyritic chalcopyrite and porphyry chalcopyrite was also studied in this paper. It is found that ATF6 is selectively adsorbed by the two different types of chalcopyrite; the higher adsorption onto the pyritic chalcopyrite than the porphyry chalcopyrite leads to the higher copper dissolution rate of the pyritic chalcopyrite. In addition, the zeta-potential of chalcopyrite before and after bioleaching further confirms that ATF6 is more easily adsorbed onto the pyritic chalcopyrite.

Stone Quarries and Sourcing in the Carolina Slate Belt

DTIC Science & Technology

2006-04-01

a hilltop with a localized outcrop of small boulders of andesite porphyry . A revisit revealed that the site had recently been destroyed by...rocks are dacitic and include flows, tuffs, breccias, and porphyries . Metasedimentary rocks are metamudstone and fine metasandstone. The Uwharrie...Rocks of this zone, from Shingle Trap, Hattaway, and Sugarloaf Mountains, are mainly light to dark gray metadacite porphyry or metadacitic

Relationships between mineralization and silicic volcanism in the central Andes

NASA Technical Reports Server (NTRS)

Francis, P. W.; Halls, C.; Baker, M. C. W.

1983-01-01

Existing models for the genesis of porphyry copper deposits indicate that they formed in granodioritic stocks located in the infrastructure of andesitic stratovolcanoes. It is noted that sites of porphyry-type subvolcanic tin mineralization in the Eastern Cordillera of Bolivia are distinguished by the absence of such andesitic structures. The surface expression of a typical subvolcanic porphyry tin deposit is thought to be an extrusive dome of quartz latite porphyry, sometimes related to a larger caldera structure. Evidence from the El Salvador porphyry copper deposit in the Eocene magmatic belt in Chile indicates that it too may be more closely related to a silicic volcanic structure than to an andesitic stratovolcano. The dome of La Soufriere, Guadeloupe is offered as a modern analog for the surface expression of subvolcanic mineralization processes, with the phreatic eruptions there indicating the formation of hydrothermal breccia bodies in depths. It is pointed out that the occurrence of mineralized porphyries, millions of years after caldera formation, does not necessarily indicate that tin intrusions and mineralization are not genetically related to the subcaldera pluton, but may be a consequence of the long thermal histories (1-10 million years) of the lowermost parts of large plutons.

Hydrothermal alteration and mass exchange in the hornblende latite porphyry, Rico, Colorado

USGS Publications Warehouse

Larson, P.B.; Cunningham, C.G.; Naeser, C.W.

1994-01-01

The Rico paleothermal anomaly, southwestern Colorado, records the effects of a large hydrothermal system that was active at 4 Ma. This hydrothermal system produced the deep Silver Creek stockwork Mo deposit, which formed above the anomaly's heat source, and shallower base and precious-metal vein and replacement deposits. A 65 Ma hornblende latite porphyry is present as widespread sills throughout the area and provided a homogenous material that recorded the effects of the hydrothermal system up to 8 km from the center. Hydrothermal alteration in the latite can be divided into a proximal facies which consists of two assemblages, quartz-illite-calcite and chlorite-epidote, and a distal facies which consists of a distinct propylitic assemblage. Temperatures were gradational vertically and laterally in the anomaly, and decreased away from the centra heat source. A convective hydrothermal plume, 3 km wide and at least 2 km high, was present above the stock-work molybdenum deposit and consisted of upwelling, high-temperature fluids that produced the proximal alteration facies. Distal facies alteration was produced by shallower cooler fluids. The most important shallow base and precious-metal vein deposits in the Rico district are at or close to the boundary of the thermal plume. Latite within the plume had a large loss of Na2O, large addition of CaO, and variable SiO2 exchante. Distal propylitized latite samples lost small amounts of Na2O and CaO and exchanged minor variable amounts of SiO2. The edge of the plume is marked by steep Na2O exchange gradients. Na2O exchange throughout the paleothermal anomaly was controlled by the reaction of the albite components in primary plagioclase and alkali feldspars. Initial feldspar alteration in the distal facies was dominated by reaction of the plagioclase, and the initial molar ratio of reactants (alkali feldspar albite component to plagioclase albite component) was 0.35. This ratio of the moles of plagioclase to alkali feldspar

Tests of Rock Cores Scott Study Area, Missouri

DTIC Science & Technology

1970-05-01

porphyry with some granodiorite and small amounts of dolomite, acid metavolcanics, and dark gray volcanic breccia. Specific gravity, * Schmidt...petrographically identified as predominantly rhyolite and dacite porphyry with some granodiorite and small amounts of dolomite, acid metavolcanics, and dark...exhibit- ing little, if any, hysteresis. 9. Direct and indirect tensile strengths exhibited by tne rhyro- lite and dacite porphyry and granite are very high

A Cultural Resources Survey of the Proposed Recreational Development Areas and Wildlife Subimpoundments at the B. Everett Jordan Dam and Lake. Volume 1.

DTIC Science & Technology

1984-03-01

containing flow banding, light-gray felsite, felsic- porphyries , crystal tuffs, and rare mafic porphyries and crystal tuffs (Conley and Bain 1965:12Z). The...goods are also present in the form of glass beads, gunflints, iron axes, copper hawk bells and white clay trade pipes. HISTORICAL BACKGROUND The...points manufactured on two rock types occur most frequently: andesitic felsite in the lower valley and grey latite porphyry in the upper valley. The

Broadband Seismic Recordings of Mining Explosions and Earthquakes in South America.

DTIC Science & Technology

1997-02-04

mineralization in Chile are closely linked to the development of the Andean cordillera since late Paleozoic time. The porphyry copper deposits occupy a...sinuous belt over 2000 km long and 30 km wide that overlap with parts of the present day active volcanic arc. The porphyry copper deposits are... porphyry copper mine. The Pliocene age Disputada stock has a mineralized area covering about 12km2 (Bernstein, 1990). The Andina mines Sur-Sur (open

An Analysis of the Mineral Industries of the Republics of China, the Philippines, and Korea, the Kingdom of Thailand, and New Zealand. Volume 1.

DTIC Science & Technology

1984-12-01

low-grade porphyry deposits were operated in the 1960’s, but were closed down because of a lack of profitability. 27 Domestic copper reserves, for... porphyry copper -gold belt that is extensive and includes the Basay Deposit contain- ing 250 million tons of 0.4 percent copper with molybdenum, gold...Philippines as a byproduct of porphyry copper deposits. 2The only economical deposit is the *;1 5 . N 4 105 Basay Deposit, assaying .01 to .0125 percent

The Potential for Prophyry Copper-Molybdenum Deposits in the Eastern United States

USGS Publications Warehouse

Schmidt, Robert Gordon

1978-01-01

Several significant porphyry-type deposits of Paleozoic age are known in New England and eastern Canada. Disseminated copper-molybdenum deposits of Paleozoic age are in the Southeastern United States, and copper is produced from porphyry-type deposits of both Precambrian and Paleozoic age in eastern Canada. Although these old deposits are surely less abundant than those in Cenozoic and Tertiary porphyry belts, the known Precrambrian and Paleozoic deposits in Eastern North America appear to be valid exploration targets. The difficult of 'prospecting in drift-covered and saprolite-mantled terrains suggests that all such deposits probably have not been discovered. Although such deposits are more costly to discover in this region than a massive sulfide deposit, the total amount of copper in even a medium-sized porphyry copper deposit is much greater than in most massive sulfide deposits. This report summarizes current knowledge of porphyry copper-molybdenum-type deposits in the Eastern United States and suggests more favorable areas for mineral exploration. Selected Canadian deposits are discussed because of their bearing on planning exploration in this country.

Dissolved volatile concentrations in an ore-forming magma

USGS Publications Warehouse

Lowenstern, J. B.

1994-01-01

Infrared spectroscopic measurements of glass inclusions within quartz phenocrysts from the Plinian fallout of the 22 Ma tuff of Pine Grove show that the trapped silicate melt contained high concentrations of H2O and CO2. Intrusive porphyries from the Pine Grove system are nearly identical in age, composition, and mineralogy to the tephra, and some contain high-grade Mo mineralization. Assuming that the porphyry magmas originally contained similar abundances of volatile components as the erupted rocks, they would have been saturated with fluid at pressures far greater than those at which the porphyries were emplaced and mineralized. The data are consistent with formation of Climax-type Mo porphyry deposits by prolonged fluid flux from a large volume of relatively Mo-poor (1-5 ppm) magma. -from Author

Geology and ore deposits of the Chicago Creek area, Clear Creek County, Colorado

USGS Publications Warehouse

Harrison, J.E.; Wells, J.D.

1956-01-01

The Chicago Creek area, Clear Creek County, Colo., forms part of the Front Range mineral belt, which is a northeast-trending belt of coextensive porphyry intrusive rocks and hydrothermal veins of Tertiary age. More than $4.5 million worth of gold, silver, copper, lead, zinc, and uranium was produced from the mines in the area between 1859 and 1954. This investigation was made by the Geological survey on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission. The bedrock in the area is Precambrian and consists of igneous rocks, some of which have been metamorphosed , and metasedimentary rocks. The metasedimentary rocks include biotite-quartz-plagioclase gneiss that is locally garnetiferous, sillimanitic biotite-quartz gneiss, amphibolite, and lime-silicate gneiss. Rocks that may be metasedimentary or meta-igneous are quartz monzonite gneiss and granite gneiss and pegmatite. The granite gneiss and pegmatite locally form a migmatite with the biotitic metasedimentary rocks. These older rocks have been intruded by granodiorite, quartz, and granite pegmatite. During Tertiary time the Precambrian rocks were invaded by dikes and plugs of quartz monzonite porphyry, alaskite porphyry, granite porphyry, monzonite porphyry, bostonite and garnetiferous bostonite porphyry, quartz bostonite porphyry, trachytic granite porphyry, and biotite-quartz latite-porphyry. Solifluction debris of Wisconsin age forms sheets filling some of the high basins, covering some of the steep slopes, and filling parts of some of the valleys; talus and talus slides of Wisconsin age rest of or are mixed with solifluction debris in some of the high basins. Recent and/or Pleistocene alluvium is present along valley flats of the larger streams and gulches. Two periods of Precambrian folding can be recognized in the area. The older folding crumpled the metasedimentary rocks into a series of upright and overturned north-northeast plunging anticlines and synclines. Quartz monzonite

Permian magmatic sequences of the Bilihe gold deposit in central Inner Mongolia, China: Petrogenesis and tectonic significance

NASA Astrophysics Data System (ADS)

Liu, Chunhua; Nie, Fengjun

2015-08-01

The Bilihe gold deposit is located in the eastern section of the Ondor Sum-Yanji Suture at the southern margin of the Xing'an-Mongolian Orogenic Belt (XMOB) and the northern margin of the North China Craton (NCC), central Inner Mongolia. The magmatic rocks in the ore district are generally high-K calc-alkaline, enriched in LREE, Zr, and Hf, and depleted in HREE, Nb, Ta, and P. The magmatic evolution sequences are norite gabbro → granodiorite porphyry → granite or norite gabbro → andesite → dacite porphyry → granodiorite, which show a trend of decreasing TiO2, FeO, MgO, CaO, and P2O5 with increasing SiO2. In the Bilihe ore district, hydrothermal processes were coeval with granitic magmatism for a period of ~ 17 Myr (272-255 Ma). The ages of the granite, granodiorite porphyry, granodiorite, and dacite porphyry are 271.5-264.1 Ma, 269.8-255.8 Ma, 268.3 Ma, and 268.6-259.4 Ma, respectively. The magmatic rocks contain magmatic, hydrothermal, and magmatic-hydrothermal zircons. The magmatic zircons have δCe > 4, La < 3 ppm, and SmN/LaN > 2.5; the hydrothermal zircons have δCe < 4, La > 3 ppm, and SmN/LaN < 2.5. The Nb/Ta and Zr/Hf ratios of granodiorite are 12.7-14.99 and 40.2-46.56, respectively. The Zr/Hf ratios successively increase in the sequence of granite (27.4-29.02) → granodiorite porphyry (29.19-32.18) → dacite porphyry (33.54-38.5) → norite gabbro (36.75-38.37), and their Nb/Ta ratios are 9.09-12.38. Zircons in granodiorite yield ε Hf (t) values of - 0.29 to - 56 (n = 13) and 2.07-7.62 (n = 5), and they give a Hf two-stage model age (tDM2) of 807-4765 Ma. The ε Hf (t) values of the zircons in granite, granodiorite porphyry, and dacite porphyry are - 0.46 to 8.03, 3.17 to 10.32, and - 0.78 to 6.58, respectively, and their Hf tDM2 ages are 787-1324 Ma, 638-1091 Ma, and 868-1343 Ma, respectively. Dehydration partial melting of subducted oceanic crust resulted in the formation of dacite porphyry; partial melting of depleted mantle resulted in

Temporal evolution of bacterial communities associated with the in situ wetland-based remediation of a marine shore porphyry copper tailings deposit.

PubMed

Diaby, N; Dold, B; Rohrbach, E; Holliger, C; Rossi, P

2015-11-15

Mine tailings are a serious threat to the environment and public health. Remediation of these residues can be carried out effectively by the activation of specific microbial processes. This article presents detailed information about temporal changes in bacterial community composition during the remediation of a section of porphyry copper tailings deposited on the Bahía de Ite shoreline (Peru). An experimental remediation cell was flooded and transformed into a wetland in order to prevent oxidation processes, immobilizing metals. Initially, the top oxidation zone of the tailings deposit displayed a low pH (3.1) and high concentrations of metals, sulfate, and chloride, in a sandy grain size geological matrix. This habitat was dominated by sulfur- and iron-oxidizing bacteria, such as Leptospirillum spp., Acidithiobacillus spp., and Sulfobacillus spp., in a microbial community which structure resembled acid mine drainage environments. After wetland implementation, the cell was water-saturated, the acidity was consumed and metals dropped to a fraction of their initial respective concentrations. Bacterial communities analyzed by massive sequencing showed time-dependent changes both in composition and cell numbers. The final remediation stage was characterized by the highest bacterial diversity and evenness. Aside from classical sulfate reducers from the phyla δ-Proteobacteria and Firmicutes, community structure comprised taxa derived from very diverse habitats. The community was also characterized by an elevated proportion of rare phyla and unaffiliated sequences. Numerical ecology analysis confirmed that the temporal population evolution was driven by pH, redox, and K. Results of this study demonstrated the usefulness of a detailed follow-up of the remediation process, not only for the elucidation of the communities gradually switching from autotrophic, oxidizing to heterotrophic and reducing living conditions, but also for the long term management of the remediation

Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska

USGS Publications Warehouse

Shah, Anjana K.; Bedrosian, Paul A.; Anderson, Eric D.; Kelley, Karen D.; Lang, James

2013-01-01

We combined aeromagnetic, induced polarization, magnetotelluric, and gravity surveys as well as drillhole geologic, alteration, magnetic susceptibility, and density data for exploration and characterization of the Cu-Au-Mo Pebble porphyry deposit. This undeveloped deposit is almost completely concealed by postmineralization sedimentary and volcanic rocks, presenting an exploration challenge. Individual geophysical methods primarily assist regional characterization. Positive chargeability and conductivity anomalies are observed over a broad region surrounding the deposit, likely representing sulfide minerals that accumulated during multiple stages of hydrothermal alteration. The mineralized area occupies only a small part of the chargeability anomaly because sulfide precipitation was not unique to the deposit, and mafic rocks also exhibit strong chargeability. Conductivity anomalies similarly reflect widespread sulfides as well as water-saturated glacial sediments. Mineralogical and magnetic susceptibility data indicate magnetite destruction primarily within the Cu-Au-Mo mineralized area. The magnetic field does not show a corresponding anomaly low but the analytic signal does in areas where the deposit is not covered by postmineralization igneous rocks. The analytic signal shows similar lows over sedimentary rocks outside of the mineralized area, however, and cannot uniquely distinguish the deposit. We find that the intersection of positive chargeability anomalies with analytic signal lows, indicating elevated sulfide concentrations but low magnetite at shallow depths, roughly delineates the deposit where it is covered only by glacial sediments. Neither chargeability highs nor analytic signal lows are present where the deposit is covered by several hundred meters of sedimentary and volcanic rocks, but a 3D resistivity model derived from magnetotelluric data shows a corresponding zone of higher conductivity. Gravity data highlight geologic features within the

Paleozoic tectonic evolution of the Dananhu-Tousuquan island arc belt, Eastern Tianshan: Constraints from the magmatism of the Yuhai porphyry Cu deposit, Xinjiang, NW China

NASA Astrophysics Data System (ADS)

Wang, Yunfeng; Chen, Huayong; Han, Jinsheng; Chen, Shoubo; Huang, Baoqiang; Li, Chen; Tian, Qinglei; Wang, Chao; Wu, Jianxin; Chen, Mingxia

2018-03-01

The Yuhai intrusions (quartz diorite, granite and pyroxene diorite) are located in the eastern part of the Dananhu-Tousuquan island arc belt of the Eastern Tianshan, and associated with the early Paleozoic porphyry Cu mineralization. LA-ICP-MS zircon U-Pb dating yielded emplacement ages of 443.5 ± 4.1 Ma for the quartz diorite, 325.4 ± 2.5 Ma for the granite, and 291 ± 3.0 Ma for the pyroxene diorite. These rocks are tholeiitic to calc-alkaline and metaluminous, with A/CNK values ranging from 0.66 to 1.10. The Silurian ore-bearing Yuhai quartz diorite is rich in LREEs and LILEs (e.g., K, Ba, Pb and Sr), and depleted in HREEs and HFSEs (e.g., Nb, Ta and Ti). These rocks are MgO-rich (1.90-3.80 wt.%; Mg# = 37-72), with high Sr/Y, La/Yb and Ba/Th ratios, positive εNd(t) (6.31-6.84) and εHf(t) (13.26-16.40), low (87Sr/86Sr)i (0.7037-0.7039), and low Nb/U and Ta/U ratios. The data suggest that the quartz diorite was generated by the partial melting of subducted juvenile oceanic slab. The oxygen fugacity (ƒO2) of the quartz diorite, calculated by zircon Ce4+/Ce3+ ratios, is higher than that of the granite and pyroxene diorite, implying that the quartz diorite was more favorable to porphyry Cu mineralization. The Carboniferous Yuhai granite reveals similar geochemical features with the quartz diorite, except for the lower Mg# (27-33), and the more elevated Th/U and Th/La ratios. Furthermore, these rocks also show high εNd(t) (5.2-5.8) and εHf(t) (11.03-14.85) values, and low (87Sr/86Sr)i (0.7036-0.7037). These features indicate that the parental magma of the granite was probably derived from a juvenile lower crust with no significant mantle component involvement. Different from the Yuhai quartz diorite and granite, the early Permian Yuhai pyroxene diorite contains low SiO2 (50.76-55.74 wt.%) and high MgO (3.96-4.33 wt.%; Mg# = 40-44). The εNd(t), εHf(t) and (87Sr/86Sr)i values of the pyroxene diorite are 5.77-6.42, 7.99-12.10 and 0.7035-0.7040, respectively. The

Petrogenesis of Cretaceous volcanic-intrusive complex from the giant Yanbei tin deposit, South China: Implication for multiple magma sources, tin mineralization, and geodynamic setting

NASA Astrophysics Data System (ADS)

Li, Qian; Zhao, Kui-Dong; Lai, Pan-Chen; Jiang, Shao-Yong; Chen, Wei

2018-01-01

The giant Yanbei tin ore deposit is the largest porphyry-type tin deposit in South China. The orebodies are hosted by the granite porphyry in the central part of the Yanbei volcanic basin in southern Jiangxi Province. The Yanbei volcanic-intrusive complex mainly consists of dacitic-rhyolitic volcanic rocks, granite, granite porphyry and diabase dikes. In previous papers, the granite porphyry was considered as subvolcanic rocks, which came from the same single magma chamber with the volcanic rocks. In this study, zircon U-Pb ages and Hf isotope data, as well as whole-rock geochemical and Sr-Nd isotopic compositions of different magmatic units in the Yanbei complex are reported. Geochronologic results show that various magmatic units have different formation ages. The dacite yielded a zircon U-Pb age of 143 ± 1 Ma, and the granite porphyry has the emplacement age of 138 ± 1 Ma. Diabase dikes which represented the final stage of magmatism, yielded a zircon U-Pb age of 128 ± 1 Ma. Distinctive whole rock Sr-Nd and zircon Hf isotopic compositions suggest that these magmatic units were derived from different magma sources. The volcanic rocks were mainly derived from the partial melting of Paleoproterozoic metasedimentary rocks without additions of mantle-derived magma. The granite porphyry has an A-type geochemical affinity, and was derived from remelting of Paleo-Mesoproterozoic crustal source with involvement of a subordinate mantle-derived magma. The granite porphyry is also a typical stanniferous granite with high F (4070-6090 ppm) and Sn (7-39 ppm) contents. It underwent strongly crystal fractionation of plagioclase, K-feldspar, and accessory minerals (like apatite, Fe-Ti oxides), which may contribute to the tin mineralization. The diabase was derived by partial melting of enriched lithospheric mantle which had been metasomatised by slab-derived fluids. The change of magmatic sources reflected an increasing extensional tectonic environment, perhaps induced by slab

Geochronology and trace element geochemistry of titanite in the Machangqing Cu-Mo-dominated polymetallic deposit, Yunnan Province, southwest China

NASA Astrophysics Data System (ADS)

Fu, Yu; Sun, Xiaoming; Hollings, Pete; Li, Dengfeng; Yang, Tianjian

2018-06-01

The Machangqing Cu-Mo-dominated polymetallic deposit is a porphyry-skarn-epithermal Cu-Mo (-Au) metallogenic system located in the middle part of the Jinshajiang-Ailaoshan alkaline porphyry metallogenic belt. The skarn mineralization of the Machangqing deposit mainly occurs along the contacts between the alkalic porphyry intrusions and the surrounding Lower Ordovician Xiangyang Formation rocks. We present LA-ICP-MS U-Pb ages and trace element data for titanite from the Machangqing deposit in order to investigate the origin of this deposit. Based on mineral textures and assemblages, two types of titanite are recognized in Machangqing: magmatic titanite (Type I) from the granite porphyry and hydrothermal titanite from the mineralized skarn. The coarse-grained magmatic titanite is euhedral and occurs as discrete grains in the interstices of feldspar, quartz and biotite, whereas fine- to medium-grained hydrothermal titanite crystals (Type II) are euhedral to subhedral and occur in association with skarn minerals such as garnet, pyroxene and magnetite. Magmatic titanite has lower FeO, Al2O3, F and Nb/Ta but higher TiO2, Th/U, HFSEs and Lu/Hf than hydrothermal titanite. The magmatic titanite has higher LREE/HREE ratios and total REE contents with stronger negative Eu anomalies than its mineralized skarn counterpart. Trace elemental characteristics of hydrothermal titanite in Machangqing are consistent with relatively low F contents and oxygen fugacities when compared to the neighboring Beiya gold-dominated polymetallic deposit in the same metallogenic belt. The weighted average 206Pb/238U age of 34.3 ± 1.2 Ma of hydrothermal titanite is within error but slightly younger than the age of magmatic titanite (37.5 ± 4.1 Ma), indicating that the skarn mineralization followed the emplacement of the granite porphyry and was broadly coeval with the porphyry mineralization. The porphyry and skarn types of mineralization at Machangqing were formed from the same metallogenic

Integrated inversion of airborne geophysics over a structural geological unit: A case study for delineation of a porphyry copper zone in Iran

NASA Astrophysics Data System (ADS)

Abedi, Maysam; Fournier, Dominique; Devriese, Sarah G. R.; Oldenburg, Douglas W.

2018-05-01

This work presents the application of an integrated geophysical survey of magnetometry and frequency-domain electromagetic data (FDEM) to image a geological unit located in the Kalat-e-Reshm prospect area in Iran which has good potential for ore mineralization. The aim of this study is to concentrate on a 3D arc-shaped andesite unit, where it has been concealed by a sedimentary cover. This unit consists of two segments; the top one is a porphyritic andesite having potential for ore mineralization, especially copper, whereas the lower segment corresponds to an unaltered andesite rock. Airborne electromagnetic data were used to delineate the top segment as a resistive unit embedded in a sediment column of alluvial fan, while the lower andesite unit was detected by magnetic field data. In our research, the FDEM data were first inverted by a laterally-constrained 1D program to provide three pieces of information that facilitate full 3D inversion of EM data: (1) noise levels associated with the FDEM observations, (2) an estimate of the general conductivity structure in the prospect area, and (3) the location of the sought target. Then EM data inversion was extended to 3D using a parallelized OcTree-based code to better determine the boundaries of the porphyry unit, where a transition exists from surface sediment to the upper segment. Moreover, a mixed-norm inversion approach was taken into account for magnetic data to construct a compact and sharp susceptible andesite unit at depth, beneath the top resistive and non-susceptible segment. The blind geological unit was eventually interpreted based on a combined model of conductivity and magnetic susceptibility acquired from individually inverting these geophysical surveys, which were collected simultaneously.

Chronology, geochemistry and Sr-Nd isotope studies of Jurassic intrusions in the Diyanqinamu porphyry Mo mine, central Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Sun, Hairui; Huang, Zhilong; Li, Wenbo; Leng, Chengbiao; Ma, Deyun; Zhang, Xingchun

2014-07-01

Available cores of porphyritic granite and aplitic granite from the Diyanqinamu porphyry Mo deposit in the north central Great Xing’an Range presented an opportunity to examine and analyze Mesozoic igneous rocks far from the Paleo-Pacific subduction zone. The Diyanqinamu granites are highly fractionated I-type, distinguished from the M-, A- or S-type granite by: high SiO2, and Rb; low Zr, Nb, Y, and Ce; low Fe2O3total/MgO and (K2O + Na2O)/CaO ratios; low alumina saturation index (<1.1); low initial ISr ratios (0.70137-0.70451); positive εNd(t) values (2.37-3.77); and negative correlation between P2O5 and SiO2. The aplitic granites were generated by fractional crystallization of the porphyritic granite, as evidenced by: spatial proximity; consistent zircon U-Pb ages (156 Ma) within error; correlations between other oxides and SiO2 in Haker diagrams; low Ba, Sr, Nb, P, Ti, Eu; linear relationship in both (La/Yb)N vs. La and Sr vs. Ba diagrams; and, decreasing LREE and ∑REE with increasing SiO2. The Diyanqinamu granites have young depleted-mantle two-stage model ages (avg. TDM2 = 660 Ma) similar to those of most Mesozoic voluminous felsic magmas in northeastern China, and were likely sourced from pre-existent crustal components both “old” and juvenile that had been juxtaposed during the tectonic evolution of the Paleo-Asian Ocean. These granites project in the transitional field from syn-collision to post-collision tectonic settings on tectonic discrimination diagrams, implying emplacement in an extensional environment. Extensional volcanism and basin formation in the Great Xing’an Range region in Late Jurassic is coeval with the Diyanqinamu granites, demonstrating that post-orogenic lithospheric extension related to the closure of the Mongol-Okhotsk Ocean was the main driving force for Late Jurassic magmatism in this region.

Platinum-group element geochemistry of the Forest Reef Volcanics, southeastern Australia: Implications for porphyry Au-Cu mineralisation

NASA Astrophysics Data System (ADS)

Lowczak, Jessica N.; Campbell, Ian H.; Cocker, Helen; Park, Jung-Woo; Cooke, David R.

2018-01-01

Platinum-group element concentrations in felsic to intermediate rocks from the Forest Reef Volcanics, Cadia-Neville region, southeastern Australia have been analysed by the Ni-S fire assay-isotope dilution method. The Forest Reef Volcanics are shoshonitic to calc-alkaline in composition and fractionated to produce a wide range of compositions, with MgO varying between 9.7 and 1.8 wt.%. The interest in this suite is that it is coeval with Au-Cu porphyry-style mineralisation in the Cadia mineral district. This study uses PGE geochemistry to determine the timing of sulfide saturation, relative to volatile (ore-fluid) saturation, in the magma that gave rise to the Forest Reef Volcanics and, in turn, to assess how this timing affected the mineralisation potential of the evolving magmatic system. The Forest Reef Volcanics can be subdivided, on the basis of their contrasting PGE geochemistry, into high-Mg (>6.8 wt.% MgO) and low-Mg suites (≤6.8 wt.% MgO). Platinum, Pd and Re concentrations increase in the high-Mg samples, whereas Ir and Ru decrease and Rh concentrations remain steady, with decreasing MgO. The coupled Ir, Ru and Rh depletion is attributed to the partitioning of these elements into magnetite. The rate of Pt and Pd enrichment is not possible by closed-system fractional crystallisation alone, which suggests that the parent magma was replenished by a Pt-Pd-rich melt. In contrast, the PGE concentrations in the low-Mg samples decrease with decreasing MgO indicating the onset of sulfide saturation at 6.8 wt.% MgO, which is confirmed by the presence of spheroidal sulfide inclusions in liquidus crystals (i.e. clinopyroxene, plagioclase, magnetite). The rate of Pd depletion is appreciably less than for any other sulfide saturated felsic system for which data are available. This requires either that the amount of sulfide melt to have precipitated was unusually low, or that the rate of Pd depletion was limited by the mass of silicate melt the sulfide melt reached

Characteristics and 40Ar/39Ar geochronology of the Erdenet Cu-Mo deposit, Mongolia

USGS Publications Warehouse

Kavalieris, Imants; Khashgerel, Bat-Erdene; Morgan, Leah; Undrakhtamir, Alexander; Borohul, Adiya

2017-01-01

The Early to Middle Triassic Erdenet porphyry Cu-Mo deposit, in northern Mongolia, developed in a continent-continent arc collision zone, within the Central Asian orogenic belt. The porphyry system is related to multiple intrusions of crystal-crowded biotite granodiorite porphyry, which formed a composite stock about 900 m in diameter, with multiple porphyritic microgranodiorite dikes. Wall rocks are Late Permian to Early Triassic, medium-grained granodiorite, with similar whole-rock geochemistry, mineralogy, and composition to the granodiorite porphyry. Whole-rock analysis of the granodiorite porphyry and wall rocks shows that these rocks cannot be discriminated, but both have depleted middle heavy rare earth elements and Y, typical of fertile porphyry magmatic suites.At the current pit level (1,250 m elev), early porphyry-style quartz veins (A and B type) are locally infilled by pyrite-chalcopyrite, with subordinate bornite, but most of the chalcopyrite occurs in D veins that constitute more than 50% of the Cu grade (~0.5 wt % Cu). The 0.3 wt % Cu shell resembles a molar tooth, enveloping the granodiorite porphyry, with deeper roots extending down the wal-rock contacts. Molybdenite occurs in monomineralic veins, and in finely laminated to massive quartz-molybdenite veins.The most important alteration is quartz-muscovite, which occurs as relatively coarse (100–500 μm) alteration selvages (1–5 cm) that envelop D veins. The D veins cut illite ± kaolinite-smectite (or intermediate argillic) alteration. Intermediate argillic alteration, together with abundant pink anhydrite (commonly hydrated to gypsum), extends from at least 1,300- to 900-m elevation in the deepest drill holes, and has overprinted early potassic alteration, or relatively unaltered red granodiorite. Meter-wide zones of kaolinite cut the anhydrite-gypsum at all levels. There is an abrupt transition outward from the intermediate argillic alteration to chlorite-epidote (propylitic) alteration, at

Application of fuzzy logic and fuzzy AHP to mineral prospectivity mapping of porphyry and hydrothermal vein copper deposits in the Dananhu-Tousuquan island arc, Xinjiang, NW China

NASA Astrophysics Data System (ADS)

Zhang, Nannan; Zhou, Kefa; Du, Xishihui

2017-04-01

Mineral prospectivity mapping (MPM) is a multi-step process that ranks promising target areas for further exploration. Fuzzy logic and fuzzy analytical hierarchy process (AHP) are knowledge-driven MPM approaches. In this study, both approaches were used for data processing, based on which MPM was performed for porphyry and hydrothermal vein copper deposits in the Dananhu-Tousuquan island arc, Xinjiang. The results of the two methods were then compared. The two methods combined expert experience and the Studentized contrast (S(C)) values of the weights-of-evidence approach to calculate the weights of 15 layers, and these layers were then integrated by the gamma operator (γ). Through prediction-area (P-A) plot analysis, the optimal γ for fuzzy logic and fuzzy AHP was determined as 0.95 and 0.93, respectively. The thresholds corresponding to different levels of metallogenic probability were defined via concentration-area (C-A) fractal analysis. The prediction performances of the two methods were compared on this basis. The results showed that in MPM based on fuzzy logic, the area under the receiver operating characteristic (ROC) curve was 0.806 and 81.48% of the known deposits were predicted, whereas in MPM based on fuzzy AHP, the area under the ROC curve was 0.862 and 92.59% of the known deposits were predicted. Therefore, prediction based on fuzzy AHP is more accurate and can provide directions for future prospecting.

MX Siting Investigation. Mineral Resources Survey, Seven Additional Valleys, Nevada/Utah Siting Area. Volume IV.

DTIC Science & Technology

1981-06-23

Lead, copper , silver In brecciated Devonian (?) limestone at the contact with altered grane* Porphyry (507). Silver, lead, copper , gold. Silver, lead...rhyolite and latite. Molybdenum- quartz yamns and disseminated in quartz monaonilte porphyry ( 402) Silveir, gold, lead, Silver, gold, lead, copper ...in parentheses ) Canyon) Tfungsten, gold. silver Tungsten -irregular pipelike bodies in brocaiated and silicified copper , lead. flourspar liniestone

Intensity of quartz cathodoluminescence and trace-element content in quartz from the porphyry copper deposit at Butte, Montana

USGS Publications Warehouse

Rusk, B.G.; Reed, M.H.; Dilles, J.H.; Kent, A.J.R.

2006-01-01

Textures of hydrothermal quartz revealed by cathodoluminescence using a scanning electron microscope (SEM-CL) reflect the physical and chemical environment of quartz formation. Variations in intensity of SEM-CL can be used to distinguish among quartz from superimposed mineralization events in a single vein. In this study, we present a technique to quantify the cathodoluminescent intensity of quartz within individual and among multiple samples to relate luminescence intensity to specific mineralizing events. This technique has been applied to plutonic quartz and three generations of hydrothermal veins at the porphyry copper deposit in Butte, Montana. Analyzed veins include early quartz-molybdenite veins with potassic alteration, pyrite-quartz veins with sericitic alteration, and Main Stage veins with intense sericitic alteration. CL intensity of quartz is diagnostic of each mineralizing event and can be used to fingerprint quartz and its fluid inclusions, isotopes, trace elements, etc., from specific mineralizing episodes. Furthermore, CL intensity increases proportional to temperature of quartz formation, such that plutonic quartz from the Butte quartz monzonite (BQM) that crystallized at temperatures near 750 ??C luminesces with the highest intensity, whereas quartz that precipitated at ???250 ??C in Main Stage veins luminesces with the least intensity. Trace-element analyses via electron microprobe and laser ablation-ICP-MS indicate that plutonic quartz and each generation of hydrothermal quartz from Butte is dominated by characteristic trace amounts of Al, P, Ti, and Fe. Thus, in addition to CL intensity, each generation of quartz can be distinguished based on its unique trace-element content. Aluminum is generally the most abundant element in all generations of quartz, typically between 50 and 200 ppm, but low-temperature, Main Stage quartz containing 400 to 3600 ppm Al is enriched by an order of magnitude relative to all other quartz generations. Phosphorous

USSR Report, Earth Sciences.

DTIC Science & Technology

1985-04-19

Specifics of Geology of Saryshagan Molybdenum- Copper - Porphyry Deposit (Northwestern Balkash Area) (Yu. K. Kudryavtsev, V. V. Izotov, et al...SPECIFICS’OF GEOLOGY OF SARYSHAGAN MOLYBDENUM- COPPER - PORPHYRY DEPOSIT (NORTHWESTERN BALKASH AREA) Moscow IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY... Copper , Lead and Cadmium in Ooze Water of Central Pacific (A. Ye. Kosov, T. P. Demidova; GEOKHIMIYA, No 10, Oct 84) 37 Nickel Minerals in

Discrimination between mineralized and unmineralized alteration zones using primary geochemical haloes in the Darreh-Zar porphyry copper deposit in Kerman, southeastern Iran

NASA Astrophysics Data System (ADS)

Parsapoor, A.; Khalili, M.; Maghami, M.

2017-08-01

Primary geochemical haloes were studied at the Darreh-Zar porphyry Cu-deposit, southern Iran. In terms of geochemical signatures, high K2O/Na2O enrichment, HREEs and HFSE's depletion in the potassic alteration, high (La/Sm)cn, (La/Yb)cn and (Gd/Yb)cn ratios in mineralized sericitic and potassic zones and notable depletion in the REEs content in argillic alteration is recognized. Further, Mg, Li, Sc, P enrichment and W depletion can serve to separate potassic alteration from the other altered zones, while (Eu/Eu*)cn and (Ce/Ce*)cn don't show pronounced changes in different alteration zones. The coupled positive Tl, Se, S, Rb, Co, Cs, Mo, K and negative Te, Ta, Ti, Sr, Rb, As, Bi, Ga, Hf, In, Mn, Zn and Zr anomalies can be adequately used in discriminating between the mineralized zones (potassic, chlorite-sericite and sericite alterations) and the barren (propylitic zone). The behavior of the trace elements on isocon diagrams reveal that HFSEs are depleted in mineralized altered zones and display variations in the amounts in the barren facies. Zonality index in the axial direction from drill holes 146 to 124 estimates the zonality sequence as Pb-Zn-Ag-Cu-Pb-Zn in the surface horizons. The calculated zonality in five drill holes and six levels indicates that the level of 550 m at the DH 117 in the central part of the area has the highest value (0.76) for Cu. The zonality sequence from the surface to the depth is variable and can be demonstrated as follow: DH 146: Pb-Zn-Cu-Mo-Ag; DH 137: Zn-Cu-Mo-Pb-Ag; DH 117: Ag-Zn-Pb-Mo-Cu; DH: 121: Cu-Mo-Zn-Ag-Pb; DH 136: Pb-Ag-Zn-Cu-Mo; DH 124: Zn-Mo-Cu-Pb-Ag. Available data of the enrichment factors shows different enrichment for copper and molybdenum (i.e. EF > 10), selenium and silver (i.e. EF > 5), tin and LREEs (i.e. 1 < EF < 5).

Earth Observations taken by the Expedition 22 Crew

NASA Image and Video Library

2010-01-14

ISS022-E-026137 (14 Jan. 2010) --- Open Pit Mines in southern Arizona are featured in this image photographed by an Expedition 22 crew member on the International Space Station. The State of Arizona is the United States? largest producer of the metal copper, primarily mined from ore bodies known as porphyry copper deposits. Copper is a good conductor of electricity and heat, and is a vital element of virtually all of our electronic devices and components. A porphyry copper deposit is a geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. As the magma cools and crystallizes, it forms an igneous rock with large crystals embedded in a fine-grained matrix, known as porphyry. Hot fluids circulate through the magma and surrounding rocks via fractures, depositing copper-bearing and other minerals in characteristic spatial patterns that signal the nature of the ore body to a geologist. The most common approach to extracting metal-bearing ore from a porphyry copper deposit is by open-pit mining. For more details, please refer to http://earth.jsc.nasa.gov/EarthObservatory/OpenPitMinesSouthernArizona.htm.

Geochemistry, zircon U-Pb dating and Hf isotopies composition of Paleozoic granitoids in Jinchuan, NW China: Constraints on their petrogenesis, source characteristics and tectonic implication

NASA Astrophysics Data System (ADS)

Zeng, Renyu; Lai, Jianqing; Mao, Xiancheng; Li, Bin; Ju, Peijiao; Tao, Shilong

2016-05-01

Granitoids are widely distributed in Jinchuan at the southwestern margin of the North China plate, which is also an important area of mineral deposits. The research subject of this article are two Paleozoic granitoids, a cataclastic syenogranite and a granodiorite porphyry. This study presents whole rock geochemistry and zircon U-Pb-Hf isotope data for the two granitoids to determine their petrogenesis, source characteristics and tectonic significance. The cataclastic syenogranite is characterized by metaluminous composition with high potassium, and LaN/YbN from 39 to 48. The composition with strong negative Eu anomalies and Zircon saturation temperatures (TZr) from 947 to 1072 °C classify this intrusion as an A-type granite. The granodiorite porphyry is metaluminous with high sodium, sub-alkaline, LaN/YbN ratios from 27 to 32. These I-type intrusions have no Eu anomalies and TZr ranges from 818 to 845 °C. Both the cataclastic syenogranite and granodiorite porphyry show enrichment of LREE and LILE and depletion of HREE and HFSE, except Hf and Zr. Using single zircon LA-ICP-MS U-Pb dating, the emplacement age of the cataclastic syenogranite and granodiorite porphyry are determined at 433.4 ± 3.7 Ma and 361.7 ± 4.6 Ma, respectively. Zircons from the cataclastic syenogranits have uniform negative εHf(t) values (-11 ± 0.5 to -9 ± 0.5), implying the involvement of an old Palaeoproterozoic crustal source in magma genesis. The zircons from the granodiorite porphyry have εHf(t) values that range from -8 ± 1.0 to +10 ± 0.6, suggesting heterogeneous source materials involving both juvenile and ancient crust reworked crustal components. Based on the geological significance of granites at the southwestern margin of the North China plate, the closure of the North Qilian Ocean occurred at ∼444 Ma. Geochemical features suggest that the cataclastic syenogranite and granodiorite porphyry formed in an intraplate extensional and compressional setting, respectively. Hence

The late Oligocene Cevizlidere Cu-Au-Mo deposit, Tunceli Province, eastern Turkey

NASA Astrophysics Data System (ADS)

İmer, Ali; Richards, Jeremy P.; Creaser, Robert A.; Spell, Terry L.

2015-02-01

The Cevizlidere deposit, located in the Tunceli Province of eastern Anatolia, is the largest porphyry Cu-Au-Mo system in Turkey. The deposit is spatially related to a composite stock, which was emplaced into Paleozoic limestones and Paleogene andesitic rocks to the southeast of the Munzur mountains, near the southwestern margin of the Ovacık pull-apart basin. The host plutonic rocks at Cevizlidere are porphyritic, medium-K calc-alkaline diorites and granodiorites. 40Ar/39Ar incremental step-heating analysis of two igneous biotite separates obtained from syn-mineral diorite porphyry yielded late Oligocene cooling ages of 25.49 ± 0.10 and 25.10 ± 0.14 Ma, whereas hydrothermal biotite yielded an age of 24.73 ± 0.08 Ma. Re-Os ages obtained from two molybdenite separates (24.90 ± 0.10 and 24.78 ± 0.10 Ma) indicate that porphyry-style alteration and mineralization developed shortly after magma emplacement. The whole-rock geochemical composition of the Cevizlidere porphyry intrusions is consistent with derivation from partial melting of the metasomatized supra-subduction zone mantle. However, based on regional tectonic reconstructions, Oligocene magmatic activity in this area appears to be related to a major kinematic reorganization that took place at around 25 Ma, during the switch from subduction to collisional tectonics in eastern Anatolia. This kinematic switch may be attributed to break-off of the Southern Neo-Tethys oceanic slab prior to the Arabia-Eurasia continent-continent collision (~12-10 Ma) following widespread middle Eocene (50-43 Ma) arc/back-arc magmatism. In this respect, the subduction-related tectonic setting of the late Oligocene Cevizlidere porphyry deposit is similar to that of the middle Eocene Çöpler epithermal Au deposit. The late timing of Cevizlidere with respect to the Southern Neo-Tethys subduction may be comparable to some early to late Miocene porphyry-epithermal systems that lie within the contiguous Urumieh-Dokhtar belt in central

Bima field, Indonesia: a sleeping giant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prior, S.W.

1986-07-01

The recent Pertamina-ARCO Bima field discovery is 50 mi north of Jakarta, Indonesia, on the east flank of the Sunda basin. More than 1 billion bbl of oil are trapped in the Oligocene-Miocene Batu Raja Limestone within a productive area exceeding 25 mi/sup 2/. Additional oil is trapped in Oligocene Talang Akar sandstone reservoirs. The ZZZ-1 wildcat well drilled into the northern featheredge of the field in October 1974. A drill-stem test of the Batu Raja flowed 87 BOPD of heavy oil, and ZZZ-1 was plugged and abandoned as a noncommercial discovery. Postdrilling assessment suggested that the accumulation was stratigraphicallymore » controlled, and no delineation wells were drilled for 9 years. A second test of this trend was finally made in November 1983, to evaluate what was considered a separate Batu Raja closure updip from ZZZ-1. The ZU-1 well found a common oil-water contact with ZZZ-1 that suggested a structurally controlled giant field had been discovered. A series of step-out wells based on a seismic reinterpretation proved this hypothesis to be true. Phase one development drilling began in November 1985, and 57 wells should be completed within the next year. About 60 million bbl of reserves will be developed at an initial rate of about 50,000 BOPD. Phase two plans now in progress could develop an additional 40 million bbl of reserves.« less

Notes on interpretation of geophysical data over areas of mineralization in Afghanistan

USGS Publications Warehouse

Drenth, Benjamin J.

2011-01-01

Afghanistan has the potential to contain substantial metallic mineral resources. Although valuable mineral deposits have been identified, much of the country's potential remains unknown. Geophysical surveys, particularly those conducted from airborne platforms, are a well-accepted and cost-effective method for obtaining information on the geological setting of a given area. This report summarizes interpretive findings from various geophysical surveys over selected mineral targets in Afghanistan, highlighting what existing data tell us. These interpretations are mainly qualitative in nature, because of the low resolution of available geophysical data. Geophysical data and simple interpretations are included for these six areas and deposit types: (1) Aynak: Sedimentary-hosted copper; (2) Zarkashan: Porphyry copper; (3) Kundalan: Porphyry copper; (4) Dusar Shaida: Volcanic-hosted massive sulphide; (5) Khanneshin: Carbonatite-hosted rare earth element; and (6) Chagai Hills: Porphyry copper.

Geophysical ore guides along the Colorado mineral belt

USGS Publications Warehouse

Case, James E.

1967-01-01

A 40-50-mgal gravity low trends northeast along the Colorado mineral belt between Monarch Pass and Breckenridge, Colorado. The low is probably caused by a silicic Tertiary batholith of lower density than adjacent Precambrian crystalline rocks. Many major mining districts associated with silicic Tertiary intrusives are near the axis of the low. Positive and negative aeromagnetic anomalies are present over the larger silicic Tertiary intrusive bodies. A good correlation exists between the magnetic lows and zones of altered, mineralized porphyry. Apparently, original magnetite in the silicic porphyries has been altered to relatively nonmagnetic pyrite or iron oxides. The regional gravity low aids in defining the limits of the mineral belt, and the magnetic lows over the porphyries indicate specific alteration zones and the possibility of associated mineral deposits.

Pb-Sr-Nd isotopes in surficial materials at the Pebble Porphyry Cu-Au-Mo Deposit, Southwestern Alaska: can the mineralizing fingerprint be detected through cover?

USGS Publications Warehouse

Ayuso, Robert A.; Kelley, Karen D.; Eppinger, Robert G.; Forni, Francesca

2013-01-01

The Cretaceous Pebble porphyry Cu-Au-Mo deposit is covered by tundra and glacigenic sediments. Pb-Sr-Nd measurements were done on sediments and soils to establish baseline conditions prior to the onset of mining operations and contribute to the development of exploration methods for concealed base metal deposits of this type. Pebble rocks have a moderate range for 206Pb/204Pb = 18.574 to 18.874, 207Pb/204Pb = 15.484 to 15.526, and 208,Pb/204Pb = 38.053 to 38.266. Mineralized granodiorite shows a modest spread in 87Sr/86Sr (0.704354–0.707621) and 143Nd/144Nd (0.512639–0.512750). Age-corrected (89 Ma) values for the granodiorite yield relatively unradiogenic Pb (e.g., 207Pb/204Pb 87Sr/86Sr, and positive values of ɛNd (1.00–4.52) that attest to a major contribution of mantle-derived source rocks. Pond sediments and soils have similar Pb isotope signatures and 87Sr/86Sr and 143Nd/144Nd values that resemble the mineralized granodiorites. Glacial events have obscured the recognition of isotope signatures of mineralized rocks in the sediments and soils. Baseline radiogenic isotope compositions, prior to the onset of mining operations, reflect natural erosion, transport and deposition of heterogeneous till sheets that included debris from barren rocks, mineralized granodiorite and sulfides from the Pebble deposit, and other country rocks that pre- and postdate the mineralization events. Isotopic variations suggest that natural weathering of the deposit is generally reflected in these surficial materials. The isotope data provide geochemical constraints to glimpse through the extensive cover and together with other geochemical observations provide a vector to concealed mineralized rocks genetically linked with the Pebble deposit.

Hydrothermal modification of host rock geochemistry within Mo-Cu porphyry deposits in the Galway Granite, western Ireland

NASA Astrophysics Data System (ADS)

Tolometti, Gavin; McCarthy, Will

2016-04-01

Hydrothermal alteration of host rock is a process inherent to the formation of porphyry deposits and the required geochemical modification of these rocks is regularly used to indicate proximity to an economic target. The study involves examining the changes in major, minor and trace elements to understand how the quartz vein structures have influenced the chemistry within the Murvey Granite that forms part of the 380-425Ma Galway Granite Complex in western Ireland. Molybdenite mineralisation within the Galway Granite Complex occurred in close association with protracted magmatism at 423Ma, 410Ma, 407Ma, 397Ma and 383Ma and this continues to be of interest to active exploration. The aim of the project is to characterize hydrothermal alteration associated with Mo-Cu mineralisation and identify geochemical indicators that can guide future exploration work. The Murvey Granite intrudes metagabbros and gneiss that form part of the Connemara Metamorphic complex. The intrusion is composed of albite-rich pink granite, garnetiferous granite and phenocrytic orthoclase granite. Minor doleritic dykes post-date the Murvey Granite, found commonly along its margins. Field mapping shows that the granite is truncated to the east by a regional NW-SE fault and that several small subparallel structures host Mo-Cu bearing quartz veins. Petrographic observations show heavily sericitized feldspars and plagioclase and biotite which have undergone kaolinization and chloritisation. Chalcopyrite minerals are fine grained, heavily fractured found crystallized along the margins of the feldspars and 2mm pyrite crystals. Molybdenite are also seen along the margins of the feldspars, crystallized whilst the Murvey Granite cooled. Field and petrographic observations indicate that mineralisation is structurally controlled by NW-SE faults from the selected mineralization zones and conjugate NE-SW cross cutting the Murvey Granite. Both fault orientations exhibit quartz and disseminated molybdenite

Installation Restoration Program (IRP) for IRP Sites Numbers 4, 5, 7 and 14. 152 Tactical Reconnaissance Group, Nevada Air National Guard, Reno Tahoe International Airport, Reno, Nevada

DTIC Science & Technology

1996-01-01

For: HQ/ANG/CEVR Andrews AFB, Maryland Prepared By: ERM-West, Inc. 5111. N. Scottsdale Road, Suite 108 ERM Scottsdale, Arizona 85250 FINAL Document...predominantly andesite and andesite porphyry flow rock, hypabyssal intrusives, and minor siliceous welded tuff, which are commonly represented by the Kate...TERTIARY ROCKSI tuslýýj porphyry and olcomic brii I SOURCE ORNL/ETS. 1994 GEOLOGIC MAP OF THE FIGURE 3-1 RENO. NEVADA AREA 152nd TACTICAL RECONNAISSANCE

The Role of Ground Truth in Improved Identification of Mining Explosion Signals Utilization of Calibration Explosions and Acoustic Signals

DTIC Science & Technology

2000-09-01

and the Porphyry Copper District (PCD) of east central Arizona and south west New Mexico were used in gathering ground truth ranging from mine records...previous studies of large coal cast blasting operations in Wyoming that trigger the IMS (Hedlin et al. 2000), the porphyry copper region of Arizona and...local mines producing the sources. Close cooperation has been developed with the Phelps Dodge mines in Morenci, Arizona and Tyrone, New Mexico where in

Geothermal Potential of Marine Corps Air Station, Yuma, Arizona, and the Western Portion of Luke-Williams Gunnery Range

DTIC Science & Technology

1988-01-01

region appears to be a temporal as well as a spatial transition zone between the emplacement of the majority of the Arizona porphyry coppers during... Porphyry Copper Deposits of the Western Hemisphere. American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., 1978, 219 pp. 30. U.S...NWC TP 6827 S Geothermal Potential of Marine Corps Air Station, Yuma, Arizona , and the Western Portion of Luke-Williams Gunnery Range by Steven C

Data integration modeling applied to drill hole planning through semi-supervised learning: A case study from the Dalli Cu-Au porphyry deposit in the central Iran

NASA Astrophysics Data System (ADS)

Fatehi, Moslem; Asadi, Hooshang H.

2017-04-01

In this study, the application of a transductive support vector machine (TSVM), an innovative semi-supervised learning algorithm, has been proposed for mapping the potential drill targets at a detailed exploration stage. The semi-supervised learning method is a hybrid of supervised and unsupervised learning approach that simultaneously uses both training and non-training data to design a classifier. By using the TSVM algorithm, exploration layers at the Dalli porphyry Cu-Au deposit in the central Iran were integrated to locate the boundary of the Cu-Au mineralization for further drilling. By applying this algorithm on the non-training (unlabeled) and limited training (labeled) Dalli exploration data, the study area was classified in two domains of Cu-Au ore and waste. Then, the results were validated by the earlier block models created, using the available borehole and trench data. In addition to TSVM, the support vector machine (SVM) algorithm was also implemented on the study area for comparison. Thirty percent of the labeled exploration data was used to evaluate the performance of these two algorithms. The results revealed 87 percent correct recognition accuracy for the TSVM algorithm and 82 percent for the SVM algorithm. The deepest inclined borehole, recently drilled in the western part of the Dalli deposit, indicated that the boundary of Cu-Au mineralization, as identified by the TSVM algorithm, was only 15 m off from the actual boundary intersected by this borehole. According to the results of the TSVM algorithm, six new boreholes were suggested for further drilling at the Dalli deposit. This study showed that the TSVM algorithm could be a useful tool for enhancing the mineralization zones and consequently, ensuring a more accurate drill hole planning.

Late Mio-Pliocene chemical weathering of the Yulong porphyry Cu deposit in the eastern Tibetan Plateau constrained by goethite (U-Th)/He dating: Implication for Asian summer monsoon

NASA Astrophysics Data System (ADS)

Deng, Xiao-Dong; Li, Jian-Wei; Shuster, David L.

2017-08-01

Chemical weathering has provided a potentially important feedback between tectonic forcing and climate evolution of the Asian continent, although precise constraints on the timing and history of weathering are only variably documented. Here, we use goethite (U-Th)/He and 4He/3He geochronology to constrain the timing and rates of chemical weathering at the Yulong porphyry Cu deposit on the eastern Tibetan Plateau. Goethite grains have (U-Th)/He ages ranging from 6.73 ± 0.51 to 0.53 ± 0.04 Ma that correlate with independent paleoclimatic proxies inferred from supergene Mn-oxides and loess deposits under variable tectonic regimes and vegetation zones over the southeastern Asia. This correlation indicates that regional climatic conditions, especially monsoonal precipitation, controlled chemical weathering and goethite precipitation in a vast area of southeastern Asia. The goethite ages suggest that the Asian summer monsoon was relatively strong from 7 to 4.6 Ma, but weakened between 4.6 and 4 Ma, and then significantly intensified from 4 to 2 Ma. The precipitation ages of goethites collected along a 100-m-thick weathering profile decrease with depth, and indicate a downward propagation of the weathering front at rates of <6.7, 53.5 ± 10.8, and 4.8 ± 0.6 m/Ma during the intervals of 7-4, 4-2, and 2-0.7 Ma, respectively. The rapid propagation of weathering front during 4-2 Ma was caused by abrupt lowering of the water table, which was possibly related to local surface uplift or reorganization of the river systems in southeastern Tibet during this period.

Empirical and Theoretical Seismic Energy Partitioning from Explosions Under Different Confinement and Media Conditions

DTIC Science & Technology

2008-09-01

Mesa, AZ or in a faster- velocity granite porphyry at a copper mine near Morenci, AZ. The results from prior research conducted by the SPE consortium...08NA286551,2; DE-FC52-06NA273243; and DE-AC52-06NA253964 Proposal No. BAA08-97 ABSTRACT Some of the data-analysis results from the 2003 Arizona ...conditions, while explosions in higher-velocity granite porphyry are marked by interesting source anisotropy. Even though the emplacement media were

Comparative study on the passivation layers of copper sulphide minerals during bioleaching

NASA Astrophysics Data System (ADS)

Fu, Kai-bin; Lin, Hai; Mo, Xiao-lan; Wang, Han; Wen, Hong-wei; Wen, Zi-long

2012-10-01

The bioleaching of copper sulphide minerals was investigated by using A. ferrooxidans ATF6. The result shows the preferential order of the minerals bioleaching as djurleite>bornite>pyritic chalcopyrite>covellite>porphyry chalcopyrite. The residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is indicated that jarosite may not be responsible for hindered dissolution. The elemental sulfur layer on the surface of pyritic chalcopyrite residues is cracked. The compact surface layer of porphyry chalcopyrite may strongly hinder copper extraction. X-ray photoelectron spectroscopy (XPS) further confirms that the passivation layers of covellite, pyritic chalcopyrite, and porphyry chalcopyrite are copper-depleted sulphide Cu4S11, S8, and copper-rich iron-deficient polysulphide Cu4Fe2S9, respectively. The ability of these passivation layers was found as Cu4Fe2S9>Cu4S11>S8>jarosite.

The preliminary result of the δ65Cu and δ34S values of major ore minerals in the Erdenetiin-Ovoo Cu-Mo porphyry deposit, Northern Mongolia

NASA Astrophysics Data System (ADS)

KIM, Y.; Lee, I.; Oyungerel, S.; Jargal, L.; Tsedenbal, T.; Ryu, J. S.

2016-12-01

The copper isotope (δ65Cu) and sulfur isotope (δ34S) compositions of major ore minerals from the Erdenetiin-Ovoo Cu-Mo porphyry deposit were measured to trace sources of copper and sulfur, and to evaluate the precipitation environment of ore minerals. The major ore minerals are pyrite, chalcopyrite, molybdenite and chalcocite developed in the QSP (Quartz-Sericite-Pyrite) alteration zone. The sulfide minerals such as sphalerite and covellite, and carbonate ore minerals like malachite, azurite are also identified. The copper isotope ratios (65Cu/63Cu) of copper ore minerals (chalcopyrite, chalcocite, malachite, azurite, covellite and chrysocolla) were analyzed by the MC-ICPMS in KBSI located in Ochang, South Korea. The measured δ65Cu values relative to NIST 976 range from -1.01 ‰ to 5.76 ‰. The average δ65Cu values of sulfide minerals such as chalcopyrite (1.03 ‰), chalcocite (0.62 ‰) and covellite (0.51 ‰) seem to be relatively lower than those of carbonate and silicate Cu minerals such as malachite (0.24 ‰), azurite (2.17 ‰) and chrysocolla (5.76 ‰). The sulfur isotope ratios (34S/32S) of major sulfide minerals were measured by EA-CF-IRMS (Elemental Analyzer - Continuous Flow - Isotope Ratio Mass Spectrometer) in NCIRF, Seoul National University. The average δ34SV-CDT value is -1.1 ‰ indicating the magmatic signature of sulfur. There is the difference of δ34S values between sulfide minerals. While the δ34S values of pyrite, chalcopyrite and molybdenite range from -0.9 to 0.8 ‰, the δ34S values of chalcocite range from -2.6 ‰ to -1.4 ‰. These lower values might be attributed to the sulfur isotope fractionation during its precipitation.

Seaweed composition from Bintulu coast of Sarawak, Malaysia.

PubMed

Zawawi, Mohd Hafizbillah; Idris, Mohd Hanafi; Kamal, Abu Hena Mustafa; King, Wong Sing

2014-08-01

Species composition of seaweed and distribution were investigated in the coastal waters of Bintulu, Sarawak. The seaweed samples were collected during low tide between May 2011 and May 2012 from the six different stations. In total 54 species of seaweeds were identified from study areas of Bintulu coastal waters. Among them, 23 species were from Rhodophyta with 11 families, 15 species were from Phaeophyta with 2 families and 16 species were from Chlorophyta with 10 families: Seventeen species of seaweeds were recorded from the Tanjung Batu, while 23 species from Pantai Telekom, 14 species from Golden Beach, 26 species from Kuala Similajau, 12 species from Kuala Nyalau and 21 species from Batu Mandi. Seaweeds abundance was high in rocky substrate and Rhodophyta (11 families and 23 species) was the common and highest group of seaweeds in this coastal areas. Present study recorded high diversified seaweed species at the rocky shore area compare to reef area.

Rhenium

USGS Publications Warehouse

John, David A.; Seal, Robert R.; Polyak, Désirée E.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Rhenium is one of the rarest elements in Earth’s continental crust; its estimated average crustal abundance is less than 1 part per billion. Rhenium is a metal that has an extremely high melting point and a heat-stable crystalline structure. More than 80 percent of the rhenium consumed in the world is used in high-temperature superalloys, especially those used to make turbine blades for jet aircraft engines. Rhenium’s other major application is in platinum-rhenium catalysts used in petroleum refining.Rhenium rarely occurs as a native element or as its own sulfide mineral; most rhenium is present as a substitute for molybdenum in molybdenite. Annual world mine production of rhenium is about 50 metric tons. Nearly all primary rhenium production (that is, rhenium produced by mining rather than through recycling) is as a byproduct of copper mining, and about 80 percent of the rhenium obtained through mining is recovered from the flue dust produced during the roasting of molybdenite concentrates from porphyry copper deposits. Molybdenite in porphyry copper deposits can contain hundreds to several thousand grams per metric ton of rhenium, although the estimated rhenium grades of these deposits range from less than 0.1 gram per metric ton to about 0.6 gram per metric ton.Continental-arc porphyry copper-(molybdenum-gold) deposits supply most of the world’s rhenium production and have large inferred rhenium resources. Porphyry copper mines in Chile account for about 55 percent of the world’s mine production of rhenium; rhenium is also recovered from porphyry copper deposits in the United States, Armenia, Kazakhstan, Mexico, Peru, Russia, and Uzbekistan. Sediment-hosted strata-bound copper deposits in Kazakhstan (of the sandstone type) and in Poland (of the reduced-facies, or Kupferschiefer, type) account for most other rhenium produced by mining. These types of deposits also have large amounts of identified rhenium resources. The future supply of rhenium is likely

Physics Laboratory Investigation of Vocational High School Field Stone and Concrete Construction Techniques in the Central Java Province (Indonesia)

ERIC Educational Resources Information Center

Purwandari, Ristiana Dyah

2015-01-01

The investigation aims in this study were to uncover the observations of infrastructures and physics laboratory in vocational high school for Stone and Concrete Construction Techniques Expertise Field or Teknik Konstruksi Batu dan Beton (TKBB)'s in Purwokerto Central Java Province, mapping the Vocational High School or Sekolah Menengah Kejuruan…

The Reinforcement to the Citizen Participation in Taking Care of the Environmental Protection Towards a Green Moral Concept-Based Sustainable Development

ERIC Educational Resources Information Center

Syahri, Mohamad

2016-01-01

The research sites were "Blitar, Malang" and "Batu" in East Java Province, Indonesia since those areas are regarded to have problems of environmental crises. In the data collection, this study made use of four methods, namely: a) observation, b) In-depth Interviews, c) documentation, and d) focus group discussion. The results…

SHRIMP U-Pb and 40Ar/39Ar age constraints for relating plutonism and mineralization in the Boulder batholith region, Montana

USGS Publications Warehouse

Lund, K.; Aleinikoff, J.N.; Kunk, Michael J.; Unruh, D.M.; Zeihen, G.D.; Hodges, W.C.; du Bray, E.A.; O'Neill, J. M.

2002-01-01

The composite Boulder batholith, Montana, hosts a variety of mineral deposit types, including important silver-rich polymetallic quartz vein districts in the northern part of the batholith and the giant Butte porphyry copper-molybdenum pre-Main Stage system and crosscutting copper-rich Main Stage vein system in the southern part of the batholith. Previous dating studies have identified ambiguous relationships among igneous and mineralizing events. Mineralizing hydrothermal fluids for these types of deposits and magma for quartz porphyry dikes at Butte have all been considered to be late-stage differentiates of the Boulder batholith. However, previous dating studies indicated that the Boulder batholith plutons cooled from about 78 to 72 Ma, whereas copper-rich Main Stage veins at Butte were dated at about 61 Ma. Recent efforts to date the porphyry copper-molybdenum pre-Main Stage deposits at Butte resulted in conflicting estimates of both 64 and 76 Ma for the mineralizing events. Silver-rich polymetallic quartz vein deposits elsewhere in the batholith have not been dated previously. To resolve this controversy, we used the U.S. Geological Survey, Stanford, SHRIMP RG ion mic??roprobe to date single-age domains within zircons from plutonic rock samples and 40Ar/39Ar geochronology to date white mica, biotite, and K-feldspar from mineral deposits. U-Pb zircon ages are Rader Creek Granodiorite, 80.4 ?? 1.2 Ma; Unionville Granodiorite, 78.2 ?? 0.8 Ma; Pulpit Rock granite, 76.5 ?? 0.8 Ma; Butte Granite, 74.5 ?? 0.9 Ma; altered Steward-type quartz porphyry dike (I-15 roadcut), 66.5 ?? 1.0 Ma; altered Steward-type quartz porphyry dike (Continental pit), 65.7 ?? 0.9 Ma; and quartz monzodiorite of Boulder Baldy (Big Belt Mountains), 66.2 ?? 0.9 Ma. Zircons from Rader Creek Granodiorite and quartz porphyry dike samples contain Archean inheritance. The 40Ar/39Ar ages are muscovite, silver-rich polymetallic quartz vein (Basin district), 74.4 ?? 0.3 Ma; muscovite, silver

Summary of Methods for Measuring Electrical Properties of Geological Strata to Estimate Electromagnetic Shielding Effectiveness

DTIC Science & Technology

1988-04-01

commercially for conventional surface resistivity measure- ments. Lead or copper wire wrapped around an insulating cable is used for the downhole...3 x 106 -- Igneous rocks, basic Augite porphyry Kola Peninsula 9.5-12.6 105-107 Dry Basalt Berestovetskoe 15.6 5 x 10 5 Dry Basalt Kutai 10.3 5 x...acidic Granite Azerbaidjan 3.0 x 107 -- Granite Ubinskoe 0.36 x 109 3.2 x 1018 Granite Kola Peninsula 0.16 x 105 0.3 x 1016 Granite porphyry 4.5 x 10 5

Identifying areas of high economic-potential copper mineralization using ASTER data in the Urumieh-Dokhtar Volcanic Belt, Iran

NASA Astrophysics Data System (ADS)

Pour, Amin Beiranvand; Hashim, Mazlan

2012-02-01

This study investigates the application of spectral image processing methods to ASTER data for mapping hydrothermal alteration zones associated with porphyry copper mineralization and related host rock. The study area is located in the southeastern segment of the Urumieh-Dokhtar Volcanic Belt of Iran. This area has been selected because it is a potential zone for exploration of new porphyry copper deposits. Spectral transform approaches, namely principal component analysis, band ratio and minimum noise fraction were used for mapping hydrothermally altered rocks and lithological units at regional scale. Spectral mapping methods, including spectral angle mapper, linear spectral unmixing, matched filtering and mixture tuned matched filtering were applied to differentiate hydrothermal alteration zones associated with porphyry copper mineralization such as phyllic, argillic and propylitic mineral assemblages.Spectral transform methods enhanced hydrothermally altered rocks associated with the known porphyry copper deposits and new identified prospects using shortwave infrared (SWIR) bands of ASTER. These methods showed the discrimination of quartz rich igneous rocks from the magmatic background and the boundary between igneous and sedimentary rocks using the thermal infrared (TIR) bands of ASTER at regional scale. Spectral mapping methods distinguished the sericitically- and argillically-altered rocks (the phyllic and argillic alteration zones) that surrounded by discontinuous to extensive zones of propylitized rocks (the propylitic alteration zone) using SWIR bands of ASTER at both regional and district scales. Linear spectral unmixing method can be best suited for distinguishing specific high economic-potential hydrothermal alteration zone (the phyllic zone) and mineral assemblages using SWIR bands of ASTER. Results have proven to be effective, and in accordance with the results of field surveying, spectral reflectance measurements and X-ray diffraction (XRD) analysis

Typing mineral deposits using their grades and tonnages in an artificial neural network

USGS Publications Warehouse

Singer, Donald A.; Kouda, Ryoichi

2003-01-01

A test of the ability of a probabilistic neural network to classify deposits into types on the basis of deposit tonnage and average Cu, Mo, Ag, Au, Zn, and Pb grades is conducted. The purpose is to examine whether this type of system might serve as a basis for integrating geoscience information available in large mineral databases to classify sites by deposit type. Benefits of proper classification of many sites in large regions are relatively rapid identification of terranes permissive for deposit types and recognition of specific sites perhaps worthy of exploring further.Total tonnages and average grades of 1,137 well-explored deposits identified in published grade and tonnage models representing 13 deposit types were used to train and test the network. Tonnages were transformed by logarithms and grades by square roots to reduce effects of skewness. All values were scaled by subtracting the variable's mean and dividing by its standard deviation. Half of the deposits were selected randomly to be used in training the probabilistic neural network and the other half were used for independent testing. Tests were performed with a probabilistic neural network employing a Gaussian kernel and separate sigma weights for each class (type) and each variable (grade or tonnage).Deposit types were selected to challenge the neural network. For many types, tonnages or average grades are significantly different from other types, but individual deposits may plot in the grade and tonnage space of more than one type. Porphyry Cu, porphyry Cu-Au, and porphyry Cu-Mo types have similar tonnages and relatively small differences in grades. Redbed Cu deposits typically have tonnages that could be confused with porphyry Cu deposits, also contain Cu and, in some situations, Ag. Cyprus and kuroko massive sulfide types have about the same tonnages. Cu, Zn, Ag, and Au grades. Polymetallic vein, sedimentary exhalative Zn-Pb, and Zn-Pb skarn types contain many of the same metals. Sediment

[Spectral characteristics and implication of granite from pozaiying molybdenite deposits in west of Guangdong].

PubMed

An, Yan-Fei; Zhong, Li-li; Zhou, Yang-Zhang; Chen, Qing; Li, Xing-yuan

2014-06-01

Some granite samples from Pozaiying molybdenite deposits in the west of Guangdong were retrieved to characterize the spectral signature of XRD, FT-NIR and Raman. The results show that compared to the Porphyry granite and granite in the far zone, the signal of XRD and Raman of granite in near zone is weaker while the signal of FT-NIR is stronger. The authors' analyses indicate that the FWHM of quartz (101) peak in XRD, Sericite peak (4 529 cm(-1)) in FT-NIR and quartz peak in Raman shift from the latter are higher than those of former two. Those spectral characteristics indicate that compared with other samples, the content of petrogenetic mineral in samples from near zone is lower while the content of alteration mineral is higher, and its crystallinity and crystallization temperatures are both lower. The authors' studies suggest that there may be an alteration zone, embracing the granite-porphyry, which comprised low temperature mineral, and the quartz-porphyry which related to molybdenite mineralization belongs to the zone near Guanshanzhang mass.

Geologic map of the Mount Sherman 7.5' quadrangle, Lake and Park Counties, Colorado

USGS Publications Warehouse

Bohannon, Robert G.; Ruleman, Chester A.

2013-01-01

The Mount Sherman 7.5- minute quadrangle is located along the crest of the Mosquito Range in between Leadville and Fairplay, Colorado. There are eleven 13,000-foot peaks and one fourteener, Mount Sherman, within the quadrangle. General elevations range from 10,400–14,036 feet (3,200–4,278 meters). The western half of the quadrangle primarily consists of Proterozoic granitic rocks reverse faulted over Paleozoic sedimentary rocks during the Laramide orogeny of late Cretaceous and Paleocene time. Coeval to this contractional event, sills and laccoliths of the White porphyry group (which probably includes rocks equivalent to the Pando Porphyry) were emplaced in the surrounding country rocks. Igneous activity continued into the Late Eocene with the emplacement of the Sacramento Porphyry (about 43.9 Ma) and the Gray porphyry group (about 36.7 Ma), and as young as 29 Ma to the north within the Climax quadrangle. With the inception of the Rio Grande rift within the region, the Paleozoic sedimentary rocks and Late Cretaceous to early Oligocene igneous rocks were extensionally faulted and tilted to the east. This resulted in the present 20–30 degree dip-slope of these rocks on top of Proterozoic basement rocks within the eastern half of the quadrangle. This extensional regime has continued well into the Pliocene. Within the southwestern quadrant, suspicious lineaments, alignment of springs, and continuous, measureable escarpments provide reasonable evidence for Quaternary tectonic activity along the western flank of the range. Pleistocene glaciers have dramatically sculpted the region, providing exceptional exposure of the region’s bedrock and structure.

Geologic map of the Ahankashan-Rakhna basin, Badghis, Ghor, and Herat Provinces, Afghanistan, modified from the 1974 original map compilation of Y.I. Shcherbina and others

USGS Publications Warehouse

Tucker, Robert D.; Stettner, Will R.; Masonic, Linda M.; Bogdanow, Anya K.

2014-01-01

The Ahankashan and Rakhna prospect area is one of several gold and copper deposits within west-central Afghanistan. Here, various felsic to intermediate igneous porphyries intrude Lower Triassic to lower Paleogene sedimentary rocks, producing mineral and ore-bearing zones related to hydrothermal alteration, skarns, silicification, and crushing (brecciation). Mineralized skarns contain assemblages such as magnetite, magnetite-hematite, epidote-hematite, and epidote-garnet, as well as disseminations of chalcopyrite, covellite, chalcocite, cuprite, malachite, and azurite. Gold mineralization is mainly associated with zones of crushing along faults, and with small silicified igneous veins within granite and quartz porphyry.

U-Pb, Re-Os and Ar-Ar dating of the Linghou polymetallic deposit, Southeastern China: Implications for metallogenesis of the Qingzhou-Hangzhou metallogenic belt

NASA Astrophysics Data System (ADS)

Tang, Yanwen; Xie, Yuling; Liu, Liang; Lan, Tingguan; Yang, Jianling; Sebastien, Meffre; Yin, Rongchao; Liang, Songsong; Zhou, Limin

2017-04-01

The Qingzhou-Hangzhou metallogenic belt (QHMB) in Southeastern China has gained increasingly attention in recent years. However, due to the lack of reliable ages on intrusions and associated deposits in this belt, the tectonic setting and metallogenesis of the QHMB have not been well understood. The Linghou polymetallic deposit in northwestern Zhejiang Province is one of the typical deposits of the QHMB. According to the field relationships, this deposit consists of the early Cu-Au-Ag and the late Pb-Zn-Cu mineralization stages. Molybdenite samples with a mineral assemblage of molybdenite-chalcopyrite-pyrite ± quartz are collected from the copper mining tunnel near the Cu-Au-Ag ore bodies. Six molybdenite samples give the Re-Os model ages varying from 160.3 to 164.1 Ma and yield a mean age of 162.2 ± 1.4 Ma for the Cu-Au-Ag mineralization. Hydrothermal muscovite gives a well-defined Ar-Ar isochron age of 160.2 ± 1.1 Ma for the Pb-Zn-Cu mineralization. Three phases of granodioritic porphyry have been distinguished in this deposit, and LA-ICP-MS zircon U-Pb dating shows that they have formed at 158.8 ± 2.4 Ma, 158.3 ± 1.9 Ma and 160.6 ± 2.1 Ma, comparable to the obtained ages of the Cu-Au-Ag and Pb-Zn-Cu mineralization. Therefore, these intrusive rocks have a close temporal and spatial relationship with the Cu-Au-Ag and Pb-Zn-Cu ore bodies. The presences of skarn minerals (e.g., garnet) and vein-type ores, together with the previous fluid inclusion and H-O-C-S-Pb isotopic data, clearly indicate that the Cu-Au-Ag and Pb-Zn-Cu mineralization are genetically related to these granodiorite porphyries. This conclusion excludes the possibility that this deposit is of ;SEDEX; type and formed in a sag basin of continental rifts setting as previously proposed. Instead, it is proposed that the Linghou polymetallic and other similar deposits in the QHMB, such as the 150-160 Ma Yongping porphyry-skarn Cu-Mo, Dongxiang porphyry? Cu, Shuikoushan/Kangjiawang skarn Pb

The role of metasomatism in the balance of halogens in ore-forming process at porphyry Cu-Mo deposits

NASA Astrophysics Data System (ADS)

Berzina, A. N.

2009-04-01

Volatile components play an important role in the evolution of ore-magmatic systems and their ore potential. Of special interest are fluorine and chlorine compounds that principally control the transportation of ore elements by the fluid in a magmatic process and under high-temperature hydrothermal conditions. Study of the evolution of fluorine-chlorine activity in the ore-forming process and their source is usually based on analysis of their magmatic history, whereas the additional source of fluorine and chlorine released during metasomatic alteration of rocks hosting mineralization is poorly discussed in the existing literature. Based on microprobe data on Cl and F abundances in halogen-containing minerals (biotite, amphibole, apatite, titanite) in intrusive rocks and their hydrothermally altered varieties, the role of metasomatic processes in the balance of volatiles in the ore-forming system is discussed by the example of porphyry Cu-Mo deposits of Siberia (Russia) and Mongolia. Two groups of the deposits are considered: copper-molybdenum (Erdenetiin Ovoo, Mongolia and Aksug, Russia) with prevailing propylitic and phyllic alteration and molybdenum-copper (Sora, Russia), with predominant potassic alteration. All types of hydrothermal alterations have led to drastic decrease in Cl contents in metasomatic minerals as compared with halogen-containing magmatic minerals. All studied deposits (particularly those where propylitic and phyllic alteration were developed) show a nearly complete chlorine removal from altered halogen-containing rock-forming minerals (biotite and amphibole). The Cl content in amphibole decreases several times at the stage of replacement with actinolite in the process of propylitization. In the later chlorites (ripidolite and brunsvigite) that replace amphibole, actinolite, and biotite, chlorine is not detected by microprobe (detection limit 0.01-0.02% Cl). Chlorine was also not detected in white micas (muscovite-phengite series) in quartz

Geochemical Data for Samples Collected in 2007 Near the Concealed Pebble Porphyry Cu-Au-Mo Deposit, Southwest Alaska

USGS Publications Warehouse

Fey, David L.; Granitto, Matthew; Giles, Stuart A.; Smith, Steven M.; Eppinger, Robert G.; Kelley, Karen D.

2008-01-01

In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of

Contrasting hydrological processes of meteoric water incursion during magmatic-hydrothermal ore deposition: An oxygen isotope study by ion microprobe

NASA Astrophysics Data System (ADS)

Fekete, Szandra; Weis, Philipp; Driesner, Thomas; Bouvier, Anne-Sophie; Baumgartner, Lukas; Heinrich, Christoph A.

2016-10-01

Meteoric water convection has long been recognized as an efficient means to cool magmatic intrusions in the Earth's upper crust. This interplay between magmatic and hydrothermal activity thus exerts a primary control on the structure and evolution of volcanic, geothermal and ore-forming systems. Incursion of meteoric water into magmatic-hydrothermal systems has been linked to tin ore deposition in granitic plutons. In contrast, evidence from porphyry copper ore deposits suggests that crystallizing subvolcanic magma bodies are only affected by meteoric water incursion in peripheral zones and during late post-ore stages. We apply high-resolution secondary ion mass spectrometry (SIMS) to analyze oxygen isotope ratios of individual growth zones in vein quartz crystals, imaged by cathodo-luminescence microscopy (SEM-CL). Existing microthermometric information from fluid inclusions enables calculation of the oxygen isotope composition of the fluid from which the quartz precipitated, constraining the relative timing of meteoric water input into these two different settings. Our results confirm that incursion of meteoric water directly contributes to cooling of shallow granitic plutons and plays a key role in concurrent tin mineralization. By contrast, data from two porphyry copper deposits suggest that downward circulating meteoric water is counteracted by up-flowing hot magmatic fluids. Our data show that porphyry copper ore deposition occurs close to a magmatic-meteoric water interface, rather than in a purely magmatic fluid plume, confirming recent hydrological modeling. On a larger scale, the expulsion of magmatic fluids against the meteoric water interface can shield plutons from rapid convective cooling, which may aid the build-up of large magma chambers required for porphyry copper ore formation.

Geochemistry and chronology of the early Paleozoic diorites and granites in the Huangtupo volcanogenic massive sulfide (VMS) deposit, Eastern Tianshan, NW China: Implications for petrogenesis and geodynamic setting

NASA Astrophysics Data System (ADS)

Zheng, Jiahao; Chai, Fengmei; Feng, Wanyi; Yang, Fuquan; Shen, Ping

2018-03-01

The Eastern Tianshan orogen contains many late Paleozoic porphyry Cu and magmatic Cu-Ni deposits. Recent studies demonstrate that several early Paleozoic volcanogenic massive sulfide (VMS) Cu-polymetallic and porphyry Cu deposits were discovered in the northern part of Eastern Tianshan. This study presents zircon U-Pb, whole-rock geochemical, and Sr-Nd isotopic data for granites and diorites from the Huangtupo VMS Cu-Zn deposit, northern part of the Eastern Tianshan. Our results can provide constraints on the genesis of intermediate and felsic intrusions as well as early Paleozoic geodynamic setting of the northern part of Eastern Tianshan. LA-ICP-MS zircon U-Pb analyses suggest that the granites and diorites were formed at 435 ± 2 Ma and 440 ± 2 Ma, respectively. Geochemical characteristics suggest that the Huangtupo granites and diorites are metaluminous rocks, exhibiting typical subduction-related features such as enrichment in LILE and LREE and depletion in HFSE. The diorites have moderate Mg#, positive εNd(t) values (+6.4 to +7.3), and young Nd model ages, indicative of a depleted mantle origin. The granites exhibit mineral assemblages and geochemical characteristics of I-type granites, and they have positive εNd(t) values (+6.7 to +10.2) and young Nd model ages, suggesting a juvenile crust origin. The early Paleozoic VMS Cu-polymetallic and porphyry Cu deposits in the northern part of Eastern Tianshan were genetically related. The formation of the early Paleozoic magmatic rocks as well as VMS and porphyry Cu deposits in the northern part of Eastern Tianshan was due to a southward subduction of the Junggar oceanic plate.

Geology of parts of the Johnny Gulch quadrangle, Montana

USGS Publications Warehouse

Freeman, Val L.

1954-01-01

An area of about 35 square miles, situated about 30 miles southeast of Helena, Montana, was mapped during the summer of 1952 at a scale of l:24, 000. The area includes a part of the eastern foothills of the Elkhorn Mountains, and is underlain by sedimentary mad volcanic rocks of Cretaceous age that were intruded during late Cretaceous or early Tertiary time by several types of igneous rocks. The oldest rocks in the map area are the nonmarine sandstone, shale, and limestone of the Kootenai formation. These are overlain disconformably by the black shale siltstone, sandstone, and siliceous mudstone of the Colorado group that is subdivided into three map units; a lower black shale unit composed of black shale and silty shale with a basal clean sandstone, all of probable marine origin; a middle siliceous unit composed of sandstone, siltstone, and siliceous mudstone of both marine and nonmarine origin; and an upper black unit composed of black shale of marine origin. Conformably above the Colorado group are crystal lithic turfs of the Slim Sam formation; in places theme grade into and in other places are unconformably overlain by the Elkhorn Mountains volcanics composed of crystal tuff, breccia, flows, and bedded tuff of andesitic composition. The rocks of the Elkhorn Mountains volcanics and older formations have been intruded by diorite porphyry and related rocks and by hornblende quartz monzonite. The diorite porphyry and related rocks include hornblende diorite porphyry, hornblende augite diorite porphyry, augite diorite porphyry, and basalt. Resting with marked unconformity upon older rocks are volcanic sedimentary rocks of early Tertiary age that are locally overlain by thin rhyolite flows. Late Tertiary and Quaternary fans overlie the rhyolite flows. Alluvium, talus, and other mantle are present in small amounts in many parts of the area. The sedimentary rocks of the area mapped form a part of the east flank of a major anticline. A major north-south syncline to the

Application of Aquatic Insects (Ephemeroptera, Plecoptera And Trichoptera) In Water Quality Assessment of Malaysian Headwater

PubMed Central

Ab Hamid, Suhaila; Md Rawi, Che Salmah

2017-01-01

The Ephemeroptera, Plecoptera and Trichoptera (EPT) community structure and the specific sensitivity of certain EPT genera were found to be influenced by water parameters in the rivers of Gunung Jerai Forest Reserve (GJFR) in the north of peninsular Malaysia. The scores of EPT taxa richness of >10 in all rivers indicated all rivers’ habitats were non-impacted, having good water quality coinciding with Class I and Class II of Malaysian water quality index (WQI) classification of potable water. The abundance of EPT was very high in Teroi River (9,661 individuals) but diversity was lower (22 genera) than Tupah River which was highly diverse (28 genera) but lower in abundance (4,263 individuals). The lowest abundance and moderate diversity was recorded from Batu Hampar River (25 genera). Baetis spp. and Thalerosphyrus spp., Neoperla spp. and Cheumatopsyche spp. were the most common genera found. Classification for all rivers using EPT taxa Richness Index and WQI gave different category of water quality, respectively. The WQI classified Tupah and Batu Hampar rivers into Class II and Teroi River (Class I) was two classes above the classification of the EPT taxa Richness Index. PMID:28890767

Application of Aquatic Insects (Ephemeroptera, Plecoptera And Trichoptera) In Water Quality Assessment of Malaysian Headwater.

PubMed

Ab Hamid, Suhaila; Md Rawi, Che Salmah

2017-07-01

The Ephemeroptera, Plecoptera and Trichoptera (EPT) community structure and the specific sensitivity of certain EPT genera were found to be influenced by water parameters in the rivers of Gunung Jerai Forest Reserve (GJFR) in the north of peninsular Malaysia. The scores of EPT taxa richness of >10 in all rivers indicated all rivers' habitats were non-impacted, having good water quality coinciding with Class I and Class II of Malaysian water quality index (WQI) classification of potable water. The abundance of EPT was very high in Teroi River (9,661 individuals) but diversity was lower (22 genera) than Tupah River which was highly diverse (28 genera) but lower in abundance (4,263 individuals). The lowest abundance and moderate diversity was recorded from Batu Hampar River (25 genera). Baetis spp. and Thalerosphyrus spp., Neoperla spp. and Cheumatopsyche spp. were the most common genera found. Classification for all rivers using EPT taxa Richness Index and WQI gave different category of water quality, respectively. The WQI classified Tupah and Batu Hampar rivers into Class II and Teroi River (Class I) was two classes above the classification of the EPT taxa Richness Index.

Ecology of ephemeroptera, plecoptera and trichoptera (insecta) in rivers of the gunung jerai forest reserve: diversity and distribution of functional feeding groups.

PubMed

Hamid, Suhaila Ab; Md Rawi, Che Salmah

2014-08-01

A field study was performed to describe the functional feeding groups (FFGs) of Ephemeroptera, Plecoptera and Trichoptera (EPT) in the Tupah, Batu Hampar and Teroi Rivers in the Gunung Jerai Forest Reserve (GJFR), Kedah, Malaysia. Twenty-nine genera belonging to 19 families were identified. The EPTs were classified into five FFGs: collector-gatherers (CG), collector-filterers (CF), shredders (SH), scrapers (SC) and predators (P). In this study, CG and CF were the dominant groups inhabiting all three rivers. Ephemeroptera dominated these rivers due to their high abundance, and they were also the CG (90.6%). SC were the lowest in abundance among all groups. Based on the FFGs, the Teroi River was suitable for CG, whereas the Tupah and Batu Hampar Rivers were suitable for CG and CF. The distribution of FFGs differed among the rivers (CG, χ(2) = 23.6, p = 0.00; SH, χ(2) = 10.02, p = 0.007; P, χ(2) = 25.54, p = 0.00; CF, χ(2) = 21.95, p = 0.00; SC, χ(2) = 9.31, p = 0.01). These findings indicated that the FFGs found in rivers of the GJFR represent high river quality.

Ecology of Ephemeroptera, Plecoptera and Trichoptera (Insecta) in Rivers of the Gunung Jerai Forest Reserve: Diversity and Distribution of Functional Feeding Groups

PubMed Central

Hamid, Suhaila Ab; Md Rawi, Che Salmah

2014-01-01

A field study was performed to describe the functional feeding groups (FFGs) of Ephemeroptera, Plecoptera and Trichoptera (EPT) in the Tupah, Batu Hampar and Teroi Rivers in the Gunung Jerai Forest Reserve (GJFR), Kedah, Malaysia. Twenty-nine genera belonging to 19 families were identified. The EPTs were classified into five FFGs: collector-gatherers (CG), collector-filterers (CF), shredders (SH), scrapers (SC) and predators (P). In this study, CG and CF were the dominant groups inhabiting all three rivers. Ephemeroptera dominated these rivers due to their high abundance, and they were also the CG (90.6%). SC were the lowest in abundance among all groups. Based on the FFGs, the Teroi River was suitable for CG, whereas the Tupah and Batu Hampar Rivers were suitable for CG and CF. The distribution of FFGs differed among the rivers (CG, χ2 = 23.6, p = 0.00; SH, χ2 = 10.02, p = 0.007; P, χ2 = 25.54, p = 0.00; CF, χ2 = 21.95, p = 0.00; SC, χ2 = 9.31, p = 0.01). These findings indicated that the FFGs found in rivers of the GJFR represent high river quality. PMID:25210588

The uranium-bearing nickel-cobalt-native silver deposits in the Black Hawk district, Grant County, New Mexico

USGS Publications Warehouse

Gillerman, Elliot; Whitebread, Donald H.

1953-01-01

The Black Hawk (Bullard Peak) district, Grant County, N. Mex., is 21 miles by road west of Silver City. From 1881 to 1893 more than $1,000,000.00 of high-grade silver ore is reported to have been shipped from the district. Since 1893 there has been no mining in the district except during a short period in 1917 when the Black Hawk mine was rehabilitated. Pre-Cambrian quartz diorite gneiss, which contains inclusions of quartzite, schist, monzonite, and quartz monzonite, is the most widespread rock in the district. The quartz diorite gneiss is intruded by many pre-Cambrian and younger rocks, including diorite granite, diabase, monzonite porphyry and andesite and is overlain by the Upper Cretaceous Beartooth quartzite. The monzonite porphyry, probably of late Cretaceous or early Tertiary age, forms a small stock along the northwestern edge of the district and numerous dikes and irregular masses throughout the district. The ore deposits are in fissure veins that contain silver, cobalt, and uranium. The ore minerals, which include native silver, niccolite, millerite, skutterudite, nickel skutterudite, bismuthinite, pitchblende, and sphalerite, are in a carbonate gangue in narrow, persistent veins, most of which trend northeasterly. Pitchblende has been identified in the Black Hawk and the Alhabra deposits and unidentified radioactive minerals were found at five other localities. The deposits that contain the radioactive minerals constitude a belt 600 to 1,500 feet wide that trends about N. 45° E., and is approximately parallel to the southeastern boundary of the monzonite porphyry stock. All the major ore deposits are in the quartz diorite gneiss in close proximity to the monzonite porphyry. The ore deposits are similar to the deposits at Great Bear Lake, Canada, and Joachimstahl, Czechoslovakia.

Magma emplacement mechanisms and syn-magmatic deformation - a new approach to the Knaben area in Vest Agder, Norway

NASA Astrophysics Data System (ADS)

Stormoen, Martin Austin; Slagstad, Trond; Henderson, Iain

2014-05-01

The Knaben area, known for its molybdenite mining, defines a N-S striking (~30 degrees dip towards the east) belt, consisting of porphyry granite with a varying density of amphibolite and varieties of deformed granite, lying within the Sirdal Magmatic Belt, is important for understanding the emplacement- and deformation mechanisms of the batholith. Detailed geological mapping combined with geochronology, geochemistry, and structural geology will be the focus areas. Last autumn's fieldwork indicated that several of the formerly mapped enclaves of amphibolite and deformed granite are more coherent then previously indicated, and some have been followed for a few kilometres. Several varieties of granite make up the area, mainly a dominating red porphyry granite, and a grey molybdenite-bearing finer grained granite. Structural investigations revealed consistent "top to the west" compressional kinematics on mappable shear zone networks often displaying west-directed duplex geometries. The Knaben area could possibly comprise a boundary between two individual plutons in the Sirdal Magmatic Belt, or a zone with remaining host rock. Geochronology of the eastern and western plutons will be done. Currently, largely different paleomagnetic vectors of the eastern and western porphyry granites indicate that they are separate plutons. Exploring how the emplacement- and deformation mechanisms have acted and are related, will be one of the main objectives. If the deformed granite is host rock, or syn- to post-magmatic deformed porphyry granite has been one of the major questions. A better understanding of the formation of the Knaben area, also regarding the emplacement of molybdenite, will prove useful for understanding the regional batholith, and possibly the possibility for molybdenite to occur elsewhere. The Sirdal Magmatic Belt, and also Knaben, seem to be of great value for studying magmatic processes.

Microthermometry of enargite-hosted fluid inclusions from the Lepanto, Philippines, high-sulfidation Cu sbnd Au deposit

NASA Astrophysics Data System (ADS)

Mancano, D. P.; Campbell, A. R.

1995-10-01

The spatial relation between porphyry and high-sulfidation epithermal deposits is particularly well revealed in the Mankayan mineral district of northern Luzon, Philippines, where the Lepanto high-sulfidation Cu sbnd Au deposit lies over and adjacent to the Far Southeast (FSE) porphyry Cu sbnd Au deposit. Consequently, a study was undertaken to characterize the fluids responsible for epithermal mineralization in this environment. The ore stage at Lepanto consists of enargite-luzonite (Cu 3AsS 4), pyrite, tennantite-tetrahedrite, and chalcopyrite. Infrared petrography of the enargite reveals variable transparency, with growth banding and twinning visible in euhedral specimens. Two phase (liquid > vapor) fluid inclusions occur as primary and secondary types ranging from <1 to 80 micrometers in length, with tabular, cylindrical, or oval shapes. Homogenization temperatures ( Th) of fluid inclusions in enargite were measured from within the lateral (3.0 km) and vertical (0.5 km) extent of the enargite mineralization. These values show a cooling trend toward the northwest, away from the area over the porphyry deposit, with average Th ranging from 285°C (proximal) to 166°C (distal). Ice melting temperatures ( Tm) were measured using a cycling technique, as ice was usually not visible in frozen inclusions. Apparent salinities range from 4.5 to 0.2 eq. wt% NaCl, with samples from the margins of the deposit showing a general decrease in apparent salinity with lower Th. Secondary fluid inclusions in quartz phenocrysts tend to have a higher average Th and lower apparent salinities compared to enargite-hosted inclusion fluids from the same locations. Several samples of pyrite are also transparent to IR radiation, and show internal features such as growth banding, and in one instance a two phase (liquid > vapor) fluid inclusion. This inclusion yielded a salinity of 1.2 eq. wt% NaCl. There is a large discrepancy in Th and apparent salinities between the enargite mineralization

Geochronology and geochemistry of the granitoids and ore - forming age in the Xiaoyao tungsten polymetallic skarn deposit in the Jiangnan Massif tungsten belt, China: Implications for their petrogenesis, geodynamic setting, and mineralization

NASA Astrophysics Data System (ADS)

Su, Qiangwei; Mao, Jingwen; Wu, Shenghua; Zhang, Zhaochong; Xu, Shengfa

2018-01-01

The Xiaoyao tungsten polymetallic skarn deposit in the eastern Jiangnan Massif of Yangtze Block is located at the contact between a granodiorite pluton and Sinian-Cambrian limestone. The intrusions in the tungsten-rich district comprise the Xiaoyao and other granodiorite plutons and granite porphyry dikes. The age determinations by LA-ICP-MS U-Pb dating of zircons indicate that the granodiorite formed at 149.4 ± 1.1 Ma, whereas the granite porphyry was emplaced at 133.2 ± 0.7 Ma. Re-Os dating of molybdenite from the skarn orebodies yielded a weighted average age of 148.7 ± 2.3 Ma (n = 5). These ages indicate that the tungsten mineralization is temporally related to the granodiorite. The granodiorites are metaluminous (A/CNK = 0.86-0.98) and in the high-K calc-alkaline series. They contain hornblende and have a negative correlation between P2O5 and SiO2, indicating that they are typical I-type intrusions. The granite porphyries exhibit high alkali contents (Na2O + K2O = 7.97-9.53%), elevated FeOT/(FeOT + MgO) ratios (0.83-0.94), high concentrations of Zr, Nb, Ce, and Y, and high Zr saturation temperatures (average of 812 °C); thus, they are geochemically similar to A-type intrusions. The initial 87Sr/86Sr and εNd(t) values range respectively from 0.7074 to 0.7083 and from - 7.9 to - 1.3 for the granodiorite, and from 0.7008 to 0.7083 and from - 6.3 to - 4.7 for the granite porphyry. In addition, two-stage Nd model ages (T2DM) of 1.0-1.6 Ga for the granodiorite and 1.3-1.4 Ga for the granite porphyry indicate that the Proterozoic crustal rocks of the Shangxi Group could have contributed to the Xiaoyao magmas. The rhenium contents of the molybdenite grains vary from 32 to 136 ppm, suggesting that the molybdenum was derived mainly from a mixture of mantle and crustal sources. Based on the new geochemical data and regional geological investigations, we propose that the Late Jurassic mineralization-related I-type granodiorite was derived from the Neoproterozoic

Publications - PIR 2016-2 | Alaska Division of Geological & Geophysical

Science.gov Websites

; Core Drilling; Cretaceous; Geologic Materials Center; Gold; Hayes Glacier Belt; Holocene; Intrusion ; Molybdenum; Placer Gold; Porphyry; Tellurium Top of Page Department of Natural Resources, Division of

SHRIMP and 40Ar/39Ar age constraints for timing of plutonism and mineralization in the Boulder batholith

USGS Publications Warehouse

Lund, K.D.; Aleinikoff, John N.; Kunk, Michael J.; Unruh, Dan M.; Zeihen, G.D.; Hodges, W.C.; du Bray, Edward A.; O'Neill, J. Michael

2002-01-01

The 66 Ma age for the quartz monzodiorite of Boulder Baldy and consideration of previous dating studies in the region indicate that small ca. 66 Ma plutonic systems may be common in the Boulder batholith region and especially to the east. The approximately 64 Ma porphyry copper systems at Butte and gold mineralization at Miller Mountain are indicative of regionally important mineralizing systems of this age in the Boulder batholith region. Resolution of the age and probable magmatic source of the Butte pre-Main Stage porphyry copper-molybdenum system and of the silver-rich polymetallic quartz vein systems in the northern part of the Boulder batholith documents that these deposits formed from two discrete periods of hydrothermal mineralization related to two discrete magmatic events.

Developing cluster strategy of apples dodol SMEs by integration K-means clustering and analytical hierarchy process method

NASA Astrophysics Data System (ADS)

Mustaniroh, S. A.; Effendi, U.; Silalahi, R. L. R.; Sari, T.; Ala, M.

2018-03-01

The purposes of this research were to determine the grouping of apples dodol small and medium enterprises (SMEs) in Batu City and to determine an appropriate development strategy for each cluster. The methods used for clustering SMEs was k-means. The Analytical Hierarchy Process (AHP) approach was then applied to determine the development strategy priority for each cluster. The variables used in grouping include production capacity per month, length of operation, investment value, average sales revenue per month, amount of SMEs assets, and the number of workers. Several factors were considered in AHP include industry cluster, government, as well as related and supporting industries. Data was collected using the methods of questionaire and interviews. SMEs respondents were selected among SMEs appels dodol in Batu City using purposive sampling. The result showed that two clusters were formed from five apples dodol SMEs. The 1stcluster of apples dodol SMEs, classified as small enterprises, included SME A, SME C, and SME D. The 2ndcluster of SMEs apples dodol, classified as medium enterprises, consisted of SME B and SME E. The AHP results indicated that the priority development strategy for the 1stcluster of apples dodol SMEs was improving quality and the product standardisation, while for the 2nd cluster was increasing the marketing access.

Factors Influencing the Effectiveness of Inventory Management in Manufacturing SMEs

NASA Astrophysics Data System (ADS)

Chan, Shiau Wei; Tasmin, R.; Nor Aziati, A. H.; Zuraidah Rasi, Raja; Ismail, Fadillah Binti; Yaw, Li Ping

2017-08-01

Effectiveness of inventory management is a vital part in the manufacturing organization to be more competitive. The previous studies have indicated that there are several factors influencing the effectiveness of inventory management in the organization but there is lack of researchers who carried out the research in the manufacturing small medium enterprise in Johor. Therefore, the purpose of this research is to identify the problem of inventory management faced by the manufacturing small medium enterprise and also to determine the factors that will influence the effectiveness of inventory management. In completing this research, 80 employees were selected randomly from the manufacturing small medium enterprise in Batu Pahat, Johor and they were requested to complete questionnaires. The result have shown that the problems of inventory management faced by manufacturing organization were underproduction, overproduction, stock out situation, delays in the delivery of raw materials and discrepancy of records. The factors, documentation/store records, planning, knowledge of employees/staff skill have shown to significantly influence the effectiveness of inventory management while the funds have shown slightly significant influence on the inventory management in manufacturing small medium enterprises. This quantitative study is important to the manufacturing organization in Malaysia because it provides the guidelines to the employers of manufacturing small medium enterprises in Batu Pahat, Johor.

Regional geochemical studies in the Patagonia Mountains, Santa Cruz County, Arizona

USGS Publications Warehouse

Chaffee, M.A.; Hill, R.H.; Sutley, S.J.; Watterson, J.R.

1981-01-01

The Patagonia Mountains in southern Arizona contain the deeply buried porphyry copper system at Red Mountain as well as a number of other base- and precious-metal mines and prospects. The range contains complex Basin and Range geology with units ranging in age from Precambrian to Holocene. Rock types present include igneous intrusive and extrusive units as well as sedimentary and metamorphic units, most of which have been tectonically disturbed. A total of 264 stream-sediment samples were collected and analyzed for 32 elements. Geochemical maps for Sb, Ag, Pb, Te, B, Mn, Au, Zn, Cu (total), Cu (cold-extractable), and Mo, as well as for Cu (cold-extractable)/Cu (total) and Fe/Mn, are presented. Anomaly patterns for these elements generally occur over the Red Mountain deposit and (or) along a north-northwest trend parallel to the major Harshaw Creek Fault. Much of the entire area sampled contains widespread anomalies for Pb, Te, and Cu; the other elements are only locally anomalous. Various plots of ratios of Cu (cold-extractable) to Cu (total) did not produce any new information not readily apparent on either one of the two copper maps. A plot of ratios of Fe to Mn delineated many areas of pyrite mineralization. Several of these areas may represent the pyritic halos around deeply buried porphyry copper systems. The best ore guide for the Red Mountain porphyry system is the coincidence of positive anomalies of Mo, Pb, and Te and a negative anomaly of Mn. Other areas with anomalies of the same suite of elements are present within the Patagonia Mountains. It is concluded that geochemical sampling, even in a highly contaminated area, can be useful in delineating major geologic features, such as porphyry copper belts and major faults. Multielement geochemical surveys on a regional scale can effectively locate large, deeply buried, zoned mineral systems such as that at Red Mountain. Plots of element ratios, where adequately understood, can provide geochemical information

Regional Crustal Structures and Their Relationship to the Distribution of Ore Deposits in the Western United States, Based on Magnetic and Gravity Data

USGS Publications Warehouse

Hildenbrand, T.G.; Berger, B.; Jachens, R.C.; Ludington, S.

2000-01-01

Upgraded gravity and magnetic databases and associated filtered-anomaly maps of western United States define regional crustal fractures or faults that may have guided the emplacement of plutonic rocks and large metallic ore deposits. Fractures, igneous intrusions, and hydrothermal circulation tend to be localized along boundaries of crustal blocks, with geophysical expressions that are enhanced here by wavelength filtering. In particular, we explore the utility of regional gravity and magnetic data to aid in understanding the distribution of large Mesozoic and Cenozoic ore deposits, primarily epithermal and porphyry precious and base metal deposits and sediment-hosted gold deposits in the western United States cordillera. On the broadest scale, most ore deposits lie within areas characterized by low magnetic properties. The Mesozoic Mother Lodge gold belt displays characteristic geophysical signatures (regional gravity high, regional low-to-moderate background magnetic field anomaly, and long curvilinear magnetic highs) that might serve as an exploration guide. Geophysical lineaments characterize the Idaho-Montana porphyry belt and the La Caridad-Mineral Park belt (from northern Mexico to western Arizona) and thus indicate a deep-seated control for these mineral belts. Large metal accumulations represented by the giant Bingham porphyry copper and the Butte polymetallic vein and porphyry copper systems lie at intersections of several geophysical lineaments. At a more local scale, geophysical data define deep-rooted faults and magmatic zones that correspond to patterns of epithermal precious metal deposits in western and northern Nevada. Of particular interest is an interpreted dense crustal block with a shape that resembles the elliptical deposit pattern partly formed by the Carlin trend and the Battle Mountain-Eureka mineral belt. We support previous studies, which on a local scale, conclude that structural elements work together to localize mineral deposits within

Geological Model of Supercritical Geothermal Reservoir on the Top of the Magma Chamber

NASA Astrophysics Data System (ADS)

Tsuchiya, N.

2017-12-01

We are conducting supercritical geothermal project, and deep drilling project named as "JBBP: Japan Beyond Brittle Project" The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 °C under lithostatic pressures, and then pressures dropped drastically. The solubility of silica also dropped, resulting in formation of quartz veins under a hydrostatic pressure regime. Connections between the lithostatic and hydrostatic pressure regimes were key to the formation of the hydrothermal breccia veins, and the granite-porphyry system provides useful information for creation of fracture clouds in supercritical geothermal reservoirs. A granite-porphyry system, associated with hydrothermal activity and mineralization, provides a suitable natural analog for studying a deep-seated geothermal reservoir where stockwork fracture systems are created in the presence of supercritical geothermal fluids. I describe fracture networks and their formation mechanisms using petrology and fluid inclusion studies in order to understand this "beyond brittle" supercritical geothermal reservoir, and a geological

A general framework of TOPSIS method for integration of airborne geophysics, satellite imagery, geochemical and geological data

NASA Astrophysics Data System (ADS)

Abedi, Maysam; Norouzi, Gholam-Hossain

2016-04-01

This work presents the promising application of three variants of TOPSIS method (namely the conventional, adjusted and modified versions) as a straightforward knowledge-driven technique in multi criteria decision making processes for data fusion of a broad exploratory geo-dataset in mineral potential/prospectivity mapping. The method is implemented to airborne geophysical data (e.g. potassium radiometry, aeromagnetic and frequency domain electromagnetic data), surface geological layers (fault and host rock zones), extracted alteration layers from remote sensing satellite imagery data, and five evidential attributes from stream sediment geochemical data. The central Iranian volcanic-sedimentary belt in Kerman province at the SE of Iran that is embedded in the Urumieh-Dokhtar Magmatic Assemblage arc (UDMA) is chosen to integrate broad evidential layers in the region of prospect. The studied area has high potential of ore mineral occurrences especially porphyry copper/molybdenum and the generated mineral potential maps aim to outline new prospect zones for further investigation in future. Two evidential layers of the downward continued aeromagnetic data and its analytic signal filter are prepared to be incorporated in fusion process as geophysical plausible footprints of the porphyry type mineralization. The low values of the apparent resistivity layer calculated from the airborne frequency domain electromagnetic data are also used as an electrical criterion in this investigation. Four remote sensing evidential layers of argillic, phyllic, propylitic and hydroxyl alterations were extracted from ASTER images in order to map the altered areas associated with porphyry type deposits, whilst the ETM+ satellite imagery data were used as well to map iron oxide layer. Since potassium alteration is generally the mainstay of porphyry ore mineralization, the airborne potassium radiometry data was used. The geochemical layers of Cu/B/Pb/Zn elements and the first component of PCA

The La Unión Au ± Cu prospect, Camagüey District, Cuba: fluid inclusion and stable isotope evidence for ore-forming processes

NASA Astrophysics Data System (ADS)

Santana, Miriela María Ulloa; Moura, Márcia Abrahão; Olivo, Gema R.; Botelho, Nilson Francisquini; Kyser, T. Kurtis; Bühn, Bernhard

2011-01-01

The Camagüey district, Cuba, is known for its epithermal precious metal deposits in a Cretaceous volcanic arc setting. Recently, the La Unión prospect was discovered in the southern part of the district, containing gold and minor copper mineralization interpreted as porphyry type. Mineralization is hosted in a 73.0 ± 1.5 Ma calc-alkaline I-type oxidized porphyry quartz diorite intrusive within volcanic and volcaniclastic rocks of the early Cretaceous Guáimaro Formation. The porphyry is affected by propylitic alteration and crosscut by a network of quartz and carbonate veinlets and veins. Chlorite, epidote, sericite, quartz, and pyrite are the main minerals in the early veins which are cut by late carbonate and zeolite veins. Late barite pseudomorphously replaces pyrite. Gold is associated with pyrite as disseminations in the altered quartz diorite and in the veins, occurring as inclusions or filling fractures in pyrite with 4 g/t Au in bulk samples, and up to 900 ppm Au in in pyrite. Fluid inclusion and oxygen isotope data are consistent with a H2O-NaCl-(KCl) mineralizing fluid, derived from the quartz diorite magma, and trapped at least at 425°C and 1.2 kbar. This primary fluid unmixed into two fluid phases, a hypersaline aqueous fluid and a low-salinity vapor-rich fluid. Boiling during cooling may have played an important role in metal precipitation. Pyrite δ34S values for the La Unión prospect range between 0.71‰ and 1.31‰, consistent with a homogeneous magmatic sulfur source. The fluids in equilibrium with the mineralized rocks have estimated δ18O values from 8‰ to 11.8‰, calculated for a temperature range of 480-505°C. The tectonic environment of the La Unión prospect, its high gold and low copper contents, the physical-chemical characteristics of the mineralizing fluids and the isotopic signature of the alteration minerals and fluids indicate that the La Unión gold mineralization is similar to the porphyry gold type, even though the ore

Geology of Saipan, Mariana Islands; Part 2, Petrology and soils

USGS Publications Warehouse

Schmidt, R.G.; Johnson, J. H.; McCracken, R.J.

1957-01-01

The rocks that comprise the volcanic formations of Saipan are of two principal types: dacites, which are characteristically glassy, and andesites, which are comparatively crystalline. The dacites consist primarily of silicic glass, oligoclase, and silica minerals (quartz, tridymite, cristobalite, chalcedony, and opal). Minor constituents in these rocks are green hornblende, biotite, magnetite, and hematite. The andesites are composed principally of labradorite, hypersthene, augite, and subcalcrc augite. Minor but also characteristic constituents of the andesites are quartz, tridymite, cristobalite, anorthoclase, and accessory magnetite, ilmenite, rutile, and apatite. Nine varieties of dacite and andesite are recognized on the basis of chemical composition, mineralogy, and texture. These are dacite, dacite vitrophyre, dacite perlite, hornblende-bearing dacite porphyry, augite-hypersthene andesite, quartz-bearing augite-hypersthene andesite, quartz-bearing augite-hypersthene andesite porphyry, augite andesite, and hypersthene andesite.

The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico

USGS Publications Warehouse

Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L.

2006-01-01

The Mesa Formation extends from Cananea, Mexico, southeast to the Sonora River and is the main host rock of Laramide porphyry copper deposits in the Cananea District and at the Alacran porphyry prospect to the east. The Mesa consists of two members-a lower andesite and an upper dacite. The lowest part of the dacite member is a crystal tuff about 100 m thick. This tuff is the outfall of a caldera centered near the village of Ojo de Agua, dated by 40Ar/39Ar at 65.8 Ma ?0.4. The Ojo de Agua Caldera is about 9 km in diameter and is filled by a light gray biotite dacite tuff with abundant flattened pumice fragments. The volume of the caldera is estimated to be 24 km3.

Geochemical contrasts between Late Triassic ore-bearing and barren intrusions in the Weibao Cu-Pb-Zn deposit, East Kunlun Mountains, NW China: constraints from accessory minerals (zircon and apatite)

NASA Astrophysics Data System (ADS)

Zhong, Shihua; Feng, Chengyou; Seltmann, Reimar; Li, Daxin; Dai, Zhihui

2017-12-01

The Weibao copper-lead-zinc skarn deposit is located in the northern East Kunlun terrane, NW China. Igneous intrusions in this deposit consist of barren diorite porphyry (U-Pb zircon age of 232.0 ± 2.0 Ma) and ore-bearing quartz diorite and pyroxene diorite (U-Pb zircon ages of 223.3 ± 1.5 and 224.6 ± 2.9 Ma, respectively). Whole-rock major and trace element and accessory mineral (zircon and apatite) composition from these intrusions are studied to examine the different geochemical characteristics of ore-bearing and barren intrusions. Compared to the barren diorite porphyry, the ore-bearing intrusions have higher Ce4+/Ce3+ ratios of zircon and lower Mn contents of apatite, indicating higher oxidation state. Besides, apatite from the ore-bearing intrusions shows higher Cl contents and lower F/Cl ratios. These characteristics collectively suggest the higher productivity of ore-bearing quartz diorite and pyroxene diorite. When compared with ore-bearing intrusions from global porphyry Cu deposits, those from Cu-Pb-Zn skarn deposits display lower Ce4+/Ce3+ and EuN/EuN* ratios of zircon and lower Cl and higher F/Cl ratios of apatite. We conclude that these differences reflect a general geochemical feature, and that zircon and apatite composition is a sensitive tool to infer economic potential of magmas and the resulting mineralization types in intrusion-related exploration targets.

Alteration Minerals Extraction Using Airborne Hyperspectral Data Casi and Sasi in Wuyi Metallogenic Belt, China

NASA Astrophysics Data System (ADS)

Huang, Z.; Zheng, J.

2018-04-01

Hydrothermal alteration is an important content in the study of epithermal deposit, and its deep part is often accompanied by porphyry mineralization. The objective of research is to mapping the alteration minerals for mineral exploration using mixture tuned matched filtering (MTMF) approach based on airborne hyperspectral data CASI and SASI in Wuyi metallogenic belt, China, which has complex geological structure and excellent mineralization conditions and high regional forest coverage rate. Gold mineralization is closely related to the Yanshan period epithermal intrusive rocks, and often exists in external contact zone of allgovite, monzomite porphyrite, granite porphyry, quarz porphyry, et al.. The main mineral alteration types include silicification (quartz), sericitization (sericite, illite), pyritization (pyrite), chloritization (chlorite), and partial calcitization (calcite). The alteration minerals extraction based on integrated CASI_SASI reflectance data were processed by MTMF algorithm with the input imagery which was pre-processed by MNF and the input endmember spectra measured by SVC spectrometer to performs MF and add an infeasibility image. The MTMF results provide an estimate to mineral subpixel fractions leading to the abundances of alteration minerals at each pixel and alteration minerals distribution. The accuracy of alteration mineral extraction refers to the extent which it agrees with a set of reference data measured in the field reconnaissance. So the CASI_SASI airborne hyperspectral image provides the efficient way to map the detailed alteration minerals distribution for mineral exploration in high forest coverage area.

Earth Observations taken by the Expedition 15 Crew

NASA Image and Video Library

2007-09-20

ISS015-E-29867 (20 Sept. 2007) --- Bingham Canyon Mine, Utah is featured in this image photographed by an Expedition 15 crewmember on the International Space Station. The Bingham Canyon Mine (center) located approximately 32 kilometers to the southeast of Salt Lake City, UT is one of the largest open-pit mines in the world, measuring over 4 kilometers wide and 1,200 meters deep. The mine exploits a porphyry copper, a type of geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. As the magma cools and crystallizes (forming an igneous rock with large crystals in a fine-grained matrix, known as a porphyry), hot fluids circulate through the magma and surrounding rocks via fractures. This process of hydrothermal alteration typically forms copper-bearing and other minerals in spatial patterns that a geologist recognizes as a potential porphyry copper deposit. Parallel benches (stepped terraces), visible along the western pit face (center left), range from 16 to 25 meters high - these provide access for equipment to work the rock face, as well as maintaining stability of the sloping pit walls. A dark, larger roadway is also visible directly below the benches. Brown to gray, flat topped hills of gangue (waste rock) surround the pit, and are thrown into sharp relief by shadows and the oblique viewing angle of this image. Leachate reservoirs associated with ore processing are visible to the south of the city of Bingham Canyon, UT (right).

A generalized analytical solution for an inclined well in a vertically and horizontally anisotropic confined aquifer and comparisons with MODFLOW

NASA Astrophysics Data System (ADS)

Batu, Vedat

2015-01-01

In this paper, a new generalized three-dimensional complete analytical solution is presented for any well screen shape in a vertically and horizontally anisotropic confined aquifer in x-y-z Cartesian coordinates system for drawdown by taking into account the three principal hydraulic conductivities (Kx, Ky, and Kz) along the x-y-z coordinate directions. The special solution covers a partially-penetrating inclined parallelepiped as well as an inclined line source well. It has been showed that the rectangular parallelepiped screen case solution of Batu (2012) is a special case of this general solution. Like Batu (2012), the horizontal well case is a special case of this solution as well. The solution takes into account both the vertical anisotropy (azx = Kz/Kx) as well as the horizontal anisotropy (ayx = Ky/Kx) and has potential application areas to analyze pumping test drawdown data from partially-penetrating inclined wells by representing them as tiny parallelepiped as well as line sources. Apart from other verifications, the inclined well solution results have also been compared with the results of MODFLOW with very good agreement. The solution has also potential application areas for a partially-penetrating inclined parallelepiped fracture. With this new solution, both the horizontal anisotropy (ayx = Ky/Kx) as well as the vertical anisotropy (azx = Kz/Kx) can also be determined using observed drawdown data.

Geochronology and petrogenesis of the Qibaoshan Cu-polymetallic deposit, northeastern Hunan Province: Implications for the metal source and metallogenic evolution of the intracontinental Qinhang Cu-polymetallic belt, South China

NASA Astrophysics Data System (ADS)

Yuan, Shunda; Mao, Jingwen; Zhao, Panlao; Yuan, Yabin

2018-03-01

The recently recognized Qinhang metallogenic belt (QHMB) is an economically important intracontinental Mesozoic porphyry-skarn Cu-polymetallic metallogenic belt in South China. However, the origin of the ore-bearing magma and the major factors controlling the different metal assemblages in the QHMB are still unclear. The Qibaoshan deposit is a large Cu-Au-Pb-Zn-Ag-Fe deposit located at the juncture between the northern and central parts of the QHMB. In this study, new zircon U-Pb ages, Hf-O isotopic data, molybdenite Re-Os ages, and whole-rock geochemical data are combined to constrain the timing of the mineralization and the origin and petrogenesis of the ore-bearing porphyry in the Qibaoshan deposit. The ages obtained from both zircon U-Pb and molybdenite Re-Os dating fall in the Late Jurassic (between 152.7 and 148.3 Ma), revealing that this deposit is significantly younger than previously estimated (227-184 Ma). The Qibaoshan ore-bearing quartz porphyry shows variable negative zircon εHf(t) values (-14.8 to -5.5), high δ18O values (8.4 to 10.8‰), and high Mg# values (69.1 to 73.0), indicating that it formed via the partial melting of ancient crust triggered by the injection of mantle-derived magma. Zircon Hf-O isotopic modeling of the mixing of two extreme endmembers indicates that the magmatic source comprised 70-80% reworked ancient crustal components and 20-30% depleted mantle components. Based on comparisons with other ore-bearing porphyries in the QHMB, a magmatic source dominated by crust-derived material and relatively low oxygen fugacities (ΔFMQ -1.8 to ΔFMQ +0.8) was responsible for the high (Pb + Zn)/Cu ratio in the Qibaoshan deposit, and the Pb, Zn and Ag were mainly derived from the reworked ancient crust. Although four analyses of inherited Neoproterozoic zircons ( 800 Ma) have variable positive εHf(t) values (0.72 to 11.21), indicating that Neoproterozoic juvenile crust was involved in the formation of the Qibaoshan ore-bearing quartz

Origin of ore-forming fluids of the Haigou gold deposit in the eastern Central Asian Orogenic belt, NE China: Constraints from H-O-He-Ar isotopes

NASA Astrophysics Data System (ADS)

Zeng, Qingdong; He, Huaiyu; Zhu, Rixiang; Zhang, Song; Wang, Yongbin; Su, Fei

2017-08-01

The Haigou lode deposit contains 40 t of gold at an average grade of 3.5 g/t, and is one of the largest deposits in the Jiapigou gold belt located along the eastern segment of the northern margin of the North China Craton. The deposit comprises 15 gold-bearing quartz veins hosted in a Carboniferous monzonite-monzogranite stock. Cretaceous dikes consisting of diorite, diabase, and granodiorite porphyries are well developed in the deposit. The diorite porphyry dikes (130.4 ± 6.3 Ma) occur together with gold-bearing quartz veins in NNE- and NE-striking faults. Gold-bearing quartz veins crosscut the diorite porphyry dikes, and the veins are in turn crosscut by E-W-striking 124.6 ± 2.2 Ma granodiorite porphyry dikes. The mineralization mainly occurs as auriferous quartz veins with minor amounts of sulfide minerals, including pyrite, galena, chalcopyrite, and molybdenite. Gold occurs as either native gold or calaverite. Common gangue minerals in the deposit include quartz, sericite, and calcite. The deposit is characterized by various types of hydrothermal alteration, including silicification, sericitization, chloritization, potassic alteration, and carbonatization. Three stages of hydrothermal activity have been recognized in the deposit: (1) a barren quartz stage; (2) a polymetallic sulfide (gold) stage; (3) a calcite stage. Fluid inclusions in hydrothermal pyrites have 3He/4He ratios of 0.3 to 3.3 Ra and 40Ar/36Ar ratios of 351 to 1353, indicating mixing of fluids of mantle and crustal origin. Hydrothermal quartz yielded δ18O values of -1.3‰ to +7.2‰ and δD values of fluid inclusions in the quartz vary between -80‰ and -104‰. These stable isotope data also suggest mixing of magmatic and meteoric fluids. Noble gas and stable isotopic data suggest that the ore fluids have a predominant mantle source with a significant crustal component. Based on the spatial association of gold-bearing quartz veins with early Cretaceous intrusions, and the H-O-He-Ar isotopic

Gases and trace elements in soils at the North Silver Bell deposit, Pima County, Arizona

USGS Publications Warehouse

Hinkle, M.E.; Dilbert, C.A.

1984-01-01

Soil samples were collected over the North Silver Bell porphyry copper deposit near Tucson, Arizona. Volatile elements and compounds in gases derived from the soils and metallic elements in the soils were analyzed in order: (1) to see which volatile constituents of the soils might be indicative of the ore body or the alteration zones; and (2) to distinguish the ore and alteration zones by comparison of trace elements in the soil. Plots of analytical data on trace elements in soils indicated a typical distribution pattern for metals around a porphyry copper deposit, with copper, molybdenum, and arsenic concentrations higher over the ore body, and zinc, lead, and silver concentrations higher over the alteration zones. Higher than average concentrations of helium, carbon disulfide, and sulfur dioxide adsorbed on soils were found over the ore body, whereas higher concentrations of carbon dioxide and carbonyl sulfide were found over the alteration zones. ?? 1984.

Mineral exploration potential of ERTS-1 data

NASA Technical Reports Server (NTRS)

Brewer, W. A. (Principal Investigator); Erskine, M. C., Jr.; Prindle, R. O.

1973-01-01

The author has identified the following significant results. Further analysis of ERTS-1 MSS imagery of Arizona has led to division of the earlier reported three major regional fault/fracture systems into eight subdivisions. These are: System A - N40E to N50E; System B - N50W; System C - N35W; System D - N65E to N75E; System E - N-E; System F - N25W average; System G - N75W average; and System H - close to E-W. Their individual significance to known porphyry coppers and correlation to the Wasatch-Jerome and Front Orogens, the Texas Zone and Basin Range topography is postulated in the report. In this study area of Arizona the ERTS-1 mapped structural trends confirm and greatly extend some concepts of porphyry copper distribution based on prior geologic knowledge of major structural trends.

The Luanchuan Mo-W-Pb-Zn-Ag magmatic-hydrothermal system in the East Qinling metallogenic belt, China: Constrains on metallogenesis from C-H-O-S-Pb isotope compositions and Rb-Sr isochron ages

NASA Astrophysics Data System (ADS)

Cao, Hua-Wen; Zhang, Shou-Ting; Santosh, M.; Zheng, Luo; Tang, Li; Li, Dong; Zhang, Xu-Huang; Zhang, Yun-Hui

2015-11-01

The Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore district is located in the East Qinling metallogenic belt on the southern margin of the North China Craton. Two ore fields (Nannihu and Yuku) are recognized in the district, and three types of deposits are identified from the two ore fields as follows: (1) the 6 proximal porphyry-skarn type Mo-W deposits occurring at the inner contact zone of the granite porphyries, (2) the 3 middle skarn-hydrothermal type Zn deposits, and (3) the 8 distal hydrothermal type Pb-Zn-Ag deposits at the periphery of the porphyry. We present C-H-O isotope compositions of hydrothermal quartz and calcite, S-Pb isotope compositions of sulfide minerals, and sphalerite Rb-Sr isochron ages from the 17 deposits. The geochemical and geochronological data from the two ore fields all show systematic temporal and spatial variation, and primarily lead to the following inferences. (1) The temperatures and salinities of the ore-forming fluids decreased during mineralization. The ore-forming fluids gradually evolved from magmatic water to mixed magmatic-meteoric water. (2) The metallogenic components were primarily derived from igneous rocks, with increasing proportions of the materials from the ore-bearing rocks. (3) The mineralization ages of these deposits are close (147-136 Ma), which correspond to the emplacement of the granite intrusions. (4) The three types of deposits and the ore-related late Mesozoic intrusives constitute a unified magmatic-hydrothermal-mineralization system. Finally, we also suggest exploration strategies for the Luanchuan ore district.

Firm performance model in small and medium enterprises (SMEs) based on learning orientation and innovation

NASA Astrophysics Data System (ADS)

Lestari, E. R.; Ardianti, F. L.; Rachmawati, L.

2018-03-01

This study investigated the relationship between learning orientation, innovation, and firm performance. A conceptual model and hypothesis were empirically examined using structural equation modelling. The study involved a questionnaire-based survey of owners of small and medium enterprises (SMEs) operating in Batu City, Indonesia. The results showed that both variables of learning orientation and innovation effect positively on firm performance. Additionally, learning orientation has positive effect innovation. This study has implication for SMEs aiming at increasing their firm performance based on learning orientation and innovation capability.

Stratigraphic development and hydrothermal activity in the central western Cascade Range, Oregon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cummings, M.L.; Bull, M.K.; Pollock, J.M.

1990-11-10

Two volcanic sequences bounded by erosional unconformities compose the stratigraphy of the North Santiam mining district, Western Cascade Range, Oregon. Diorite, grandodiorite, and leucocratic quartz porphyry dikes, stocks, and sills intrude the breccias, flows, and tuffs of a volcanic center in the older Sardine Formation. Tourmaline-bearing breccia pipes are associated with the porphyritic granodiorite intrusions. An erosional unconformity separates the Sardine Formation from the overlying Elk Lake formation. The alteration patterns in the two formations are consistent with the development of hydrothermal systems during the eruption of each formation. However, the development of the two hydrothermal systems is separated bymore » a period of erosion of the older volcanic pile. Early formation of mineralization that resembles porphyry copper deposits occurred within the Sardine Formation, and later, after eruption of the Elk Lake formation, epithermal veins and alteration developed along faults, fractures, and the margins of dikes in the Sardine Formation.« less

Tertiary tilting and dismemberment of the laramide arc and related hydrothermal systems, Sierrita Mountain, Arizona

USGS Publications Warehouse

Stavast, W.J.A.; Butler, R.P.; Seedorff, E.; Barton, M.D.; Ferguson, C.A.

2008-01-01

Multiple lines of evidence, including new and published geologic mapping and paleomagnetic and geobarometric determinations, demonstrate that the rocks and large porphyry copper systems of the Sierrita Mountains in southern Arizona were dismembered and tilted 50?? to 60?? to the south by Tertiary normal faulting. Repetition of geologic features and geobarometry indicate that the area is segmented into at least three major structural blocks, and the present surface corresponds to oblique sections through the Laramide plutonic-hydrothermal complex, ranging in paleodepth from ???1 to ???12 km. These results add to an evolving view of a north-south extensional domain at high angles to much extension in the southern Basin and Range, contrast with earlier interpretations that the Laramide systems are largely upright and dismembered by thrust faults, highlight the necessity of restoring Tertiary rotations before interpreting Laramide structural and hydrothermal features, and add to the broader understanding of pluton emplacement and evolution of porphyry copper systems. ?? 2008 Society of Economic Geologists, Inc.

Petrology, composition, and age of intrusive rocks associated with the Quartz Hill molybdenite deposit, southeastern Alaska.

USGS Publications Warehouse

Hudson, T.; Smith, James G.; Elliott, R.L.

1979-01-01

A large porphyry molybdenum deposit (Quartz Hill deposit) was recently discovered in the heart of the Coast Range batholithic complex about 70 km E of Ketchikan, SE Alaska. Intrusive rocks associated with the mineral deposit form two composite epizonal to hypabyssal stocks and many dikes in country rocks. All observed metallization and alteration is within the Quartz Hill stock. Molybdenite forms fracture coatings and occurs in veins with quartz. Alteration is widespread and includes development of secondary quartz, pyrite, K-feldspar, biotite, white mica, chlorite, and zeolite. Field relations indicate that the stocks were emplaced after regional uplift and erosion of the Coast Range batholithic complex, and K-Ar data show that intrusion and alteration took place in late Oligocene time, about 27 to 30 Ma ago. Data from the Ketchikan quadrangle indicate that porphyry molybdenum metallization in the Coast Range batholithic complex is associated with regionally extensive but spotty, middle Tertiary or younger, felsic magmatism. -from Authors

The california poppy (eschscholtzia mexicana) as a copper indicator plant - a new example

USGS Publications Warehouse

Chaffee, M.A.; Gale, C.W.

1976-01-01

The abundance and distribution of the California poppy (Eschscholtzia mexicana) correlates closely with the copper-rich outcrop of a small porphyry-type deposit in Arizona. Chemical factors are probably more important than physical factors in determining why this species is sometimes found as a copper indicator plant. ?? 1976.

Geothermal Potential of Adak Island, Alaska

DTIC Science & Technology

1985-10-01

alteration of the Andrew Bay Hot Springs is essentially propylitic , with the introduction of pyrite and the conversion of magnetite to pyrite. This pyritic...features: Goethite coats the walls of a 1-mm fracture in this rock. Classification: Propylitically altered andesite porphyry breccia. 71 NWC TP 6676 Date: 20

Geochemical constraints on adakites of different origins and copper mineralization

USGS Publications Warehouse

Sun, W.-D.; Ling, M.-X.; Chung, S.-L.; Ding, X.; Yang, X.-Y.; Liang, H.-Y.; Fan, W.-M.; Goldfarb, R.; Yin, Q.-Z.

2012-01-01

The petrogenesis of adakites holds important clues to the formation of the continental crust and copper ?? gold porphyry mineralization. However, it remains highly debated as to whether adakites form by slab melting, by partial melting of the lower continental crust, or by fractional crystallization of normal arc magmas. Here, we show that to form adakitic signature, partial melting of a subducting oceanic slab would require high pressure at depths of >50 km, whereas partial melting of the lower continental crust would require the presence of plagioclase and thus shallower depths and additional water. These two types of adakites can be discriminated using geochemical indexes. Compiled data show that adakites from circum-Pacific regions, which have close affinity to subduction of young hot oceanic plate, can be clearly discriminated from adakites from the Dabie Mountains and the Tibetan Plateau, which have been attributed to partial melting of continental crust, in Sr/Y-versus-La/Yb diagram. Given that oceanic crust has copper concentrations about two times higher than those in the continental crust, whereas the high oxygen fugacity in the subduction environment promotes the release of copper during partial melting, slab melting provides the most efficient mechanism to concentrate copper and gold; slab melts would be more than two times greater in copper (and also gold) concentrations than lower continental crust melts and normal arc magmas. Thus, identification of slab melt adakites is important for predicting exploration targets for copper- and gold-porphyry ore deposits. This explains the close association of ridge subduction with large porphyry copper deposits because ridge subduction is the most favorable place for slab melting. ?? 2012 by The University of Chicago.

Melanesian arc far-field response to collision of the Ontong Java Plateau: Geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea

NASA Astrophysics Data System (ADS)

Holm, Robert J.; Spandler, Carl; Richards, Simon W.

2013-09-01

Understanding the evolution of the mid-Cenozoic Melanesian arc is critical for our knowledge of the regional tectonic development of the Australian-Pacific plate margin, yet there have been no recent studies to constrain the nature and timing of magmatic activity in this arc segment. In particular, there are currently no robust absolute age constraints at the plate margin related to either the initiation or cessation of subduction and arc magmatism. We present the first combined U-Pb zircon geochronology and geochemical investigation into the evolution of the Melanesian arc utilizing a comprehensive sample suite from the Simuku Igneous Complex of West New Britain, Papua New Guinea. Development of the embryonic island arc from at least 40 Ma and progressive arc growth was punctuated by distant collision of the Ontong Java Plateau and subduction cessation from 26 Ma. This change in subduction dynamics is represented in the Melanesian arc magmatic record by emplacement of the Simuku Porphyry Complex between 24 and 20 Ma. Petrological and geochemical affinities highlight genetic differences between 'normal' arc volcanics and adakite-like signatures of Cu-Mo mineralized porphyritic intrusives. The contemporaneous emplacement of both 'normal' arc volcanics and adakite-like porphyry intrusives may provide avenues for future research into the origin of diverse styles of arc volcanism. Not only is this one of few studies into the geology of the Melanesian arc, it is also among the first to address the distant tectono-magmatic effects of major arc/forearc collision events and subduction cessation on magmatic arcs, and also offers insight into the tectonic context of porphyry formation in island arc settings.

Reconstructing Magmatic-Hydrothermal Systems via Geologic Mapping of the Tilted, Cross-sectional Exposures of the Yerington District, Nevada

NASA Astrophysics Data System (ADS)

Dilles, J. H.; Proffett, J. M.

2011-12-01

The Jurassic Yerington batholith was cut by Miocene to recent normal faults and tilted ~90° west (Proffett, 1977). Exposures range from the volcanic environment to ~6 km depth in the batholith. Magmatic-hydrothermal fluids derived from the Luhr Hill granite and associated porphyry dikes produced characteristic porphyry copper mineralization and rock alteration (K-silicate, sericitic, and advanced argillic) in near-vertical columnar zones above cupolas on the deep granite. In addition, saline brines derived from the early Mesozoic volcanic and sedimentary section intruded by the batholith were heated and circulated through the batholith producing voluminous sodic-calcic and propylitic alteration. The magnetite-copper ore body at Pumpkin Hollow is hosted in early Mesozoic sedimentary rocks in the contact aureole of the batholith, and appears to be an IOCG type deposit produced where the sedimentary brines exited the batholith. Although many advances in understanding of Yerington have been made by lab-based geochronology and geochemistry studies, the first order igneous and hydrothermal features were recognized first in the 1960s and 1970s and are best documented by geological mapping at a variety of scales ranging from 1:500 to 1:24,000. The Anaconda technique of mapping mine benches, trenches, and drill cores was perfected here (Einaudi, 1997), and other techniques were used for surface exposures. The geologic and hydrothermal alteration maps establish that hydrothermal alteration accompanied each of several porphyry dike intrusions, and affected more than 100 km3 of rock. Both zonation in alteration mineralogy and vein orientations allow reconstruction of source areas and >5 km-long flow-paths of hydrothermal fluids through the batholith and contact aureole.

The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese

NASA Astrophysics Data System (ADS)

Jiang, Jun-Sheng; Zheng, You-Ye; Gao, Shun-Bao; Zhang, Yong-Chao; Huang, Jian; Liu, Jun; Wu, Song; Xu, Jing; Huang, Liang-Liang

2018-05-01

The newly discovered polymetallic Nuocang Pb-Zn skarn deposit is located in the southern Lhasa subterrane, western Gangdese, Tibet. The orebodies occur primarily at the contact zone between the Angjie Formation and the Linzizong volcanic rocks of Dianzhong Formation (LDF) that are dominated by basaltic andesitic tuff and rhyolite. Zircon U-Pb dating for two granite porphyries yield ages of 72.4 ± 0.2 Ma and 73.4 ± 0.9 Ma, which are different from the ages ( 69-60 Ma) of the LDF in the eastern Gangdese. The basaltic andesite tuff at Nuocang exhibits enrichment of MgO, TiO2, LILE, and LREE, with a relative depletion of SiO2, K2O, HFSE, and HREE, low Sr/Y ratios (32.9-38.0), and weak negative Eu anomalies (mean 0.86). They have 87Sr/86Sr(i) from 0.70695 to 0.70807 and εNd(t) values between -4.3 and -5.9. These features are similar to the Linzizong volcanic rocks of Dianzhong Formation in the Linzhou basin, indicating that they were associated with partial melting of mantle wedge mixing with 25-35% ancient Lhasa terrane basement. The rhyolite and granite porphyry show high SiO2 and K2O, and low Sr/Y ratio (1.2-9.9), enrichment of LILE and LREE and strong depletion of the HFSEs. They have pronounced negative Eu anomalies (mean 0.46), and εHf (t) values of the granite porphyry zircons range from -22.0 to -6.0. All these features suggest that they are the product of anatexis of ancient crustal materials heated by mantle-derived magma, the latter derived from Neo-Tethyan slab dehydration mechanisms. Combined with the previous geochronological and geochemical data, we proposed that the Nuocang district of western Gangdese in the southern Lhasa subterrane contains an ancient block, and the igneous rocks here were triggered by the Neo-Tethyan slab rollback starting at 82 Ma. The western Gangdese contains more ancient continental crustal materials and Late Cretaceous-Eocene Linzizong volcanic rocks and coeval intrusions than in the eastern Gangdese. Thus the western

Chronology of magmatism and mineralization in the Kassandra mining area, Greece: The potentials and limitations of dating hydrothermal illites

NASA Astrophysics Data System (ADS)

Gilg, H. Albert; Frei, Robert

1994-05-01

Various geochronological methods ( U/Pb, Rb/Sr, and K/Ar) have been applied to constrain the timing of magmatism and polymetallic mineralization in the Kassandra mining district, northern Greece. These data provide the first geochronological evidence that porphyry copper mineralization, proximal copper skarns, and distal high-temperature carbonate-hosted Pb-Zn-Ag-Au replacement ores formed contemporaneously and probably within less than 2 million years. Polymetallic mineralization is temporally related to the emplacement of granodioritic to quartz dioritic porphyries (24-25 Ma) that postdate the largest post-tectonic intrusion of the area, the Stratoni granodiorite (27.9 ± 1.2 Ma). Andesite porphyry dikes, which crosscut the Pb-Zn-Ag-Au ores and associated alterations, represent the last magmatic phase in the area (19.1 ± 0.6 Ma) and did not contribute to metal concentration. The combination of K/Ar, Rb/Sr, and oxygen isotope studies of hydrothermal illite-rich clays and careful granulometric analysis constrains the reliability of these geochronological methods and emphasizes the importance of characterizing the post-formational history of the sample. We identify various processes which partly disturbed the K/Ar and Rb/Sr system of some clays, such as retrograde alteration by heated meteoric waters, superimposed supergene illitization, and resetting of both isotopic systems due to a hydrothermal overprint related to the intrusion of the andesite porphyry. Our data, however, suggest that diffusive Ar loss from the finest clay fractions (< 0.6 μm) during cooling of the hydrothermal system probably played the most important role in the disturbance of the K/Ar system. Conventional K/Ar ages of < 2 μm fractions from high-temperature illites (> 200°C), therefore, do not give reliable formation ages. The loss of Ar may be used to model the cooling history of the hydrothermal system applying the concept of closure temperatures ( DODSON, 1973). 40K- 40Ar rad isochrons

Publications - PDF 99-24B | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska (6.4 M) Keywords Ar-Ar; Bedrock; Bedrock Geologic Map; Bedrock Geology; Economic Geology; Geochronology ; Geologic; Geologic Map; Geology; Gold; Lode; Plutonic; Plutonic Hosted; Porphyry; STATEMAP Project; Silver

Seasonal trends in abundance and composition of marine debris in selected public beaches in Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Mobilik, Julyus-Melvin; Ling, Teck-Yee; Husain, Mohd-Lokman Bin; Hassan, Ruhana

2015-09-01

The abundance and composition of marine debris were investigated at Saujana (in the state of Negeri Sembilan) and Batu Rakit (in the state of Terengganu) beaches during surveys conducted in December 2012 (northeast monsoon), May 2013 (intermediate monsoon) and July 2013 (southwest monsoon). A total of 4,682 items of debris weighing 231.4 kg were collected and sorted. Batu Rakit received substantially greater quantities of debris (815±717 items/km or 40.4±13.0 kg/km) compared to Saujana (745±444 items/km or 36.7±18.0 kg/km). Total debris item was more abundant during the southwest monsoon (SWM) (1,122±737 items/km) compared to the northeast monsoon (NEM) (825±593 items/ km) and the intermediate monsoon (IM) (394±4 items/km) seasons. Plastic category (88%) was the most numerous items collected and object items contributed 44.18% includes packaging, plastic fragments, cups, plastic shopping bags, plastic food wrapper, clear plastic bottles from the total debris items collected. Object items associated with common source (47%) were the highest debris accumulated, followed by terrestrial (30%) and marine (23%) sources. The high percentage of common and terrestrial sources during SWM season requires immediate action by marine environment stakeholders to develop and introduce strategies to reduce if not totally eliminates the marine debris in the marine environment. Awareness should be continued and focused on beach users and vessels' crew to alert them on the alarming accumulation rate of marine debris and its pathways into the marine environment.

Iterative joint inversion of in-situ stress state along Simeulue-Nias Island

NASA Astrophysics Data System (ADS)

Agustina, Anisa; Sahara, David P.; Nugraha, Andri Dian

2017-07-01

In-situ stress inversion from focal mechanisms requires knowledge of which of the two nodal planes is the fault. This is challenging, in particular, because of the inherent ambiguity of focal mechanisms the fault and the auxiliary nodal plane could not be distinguished. A relatively new inversion technique for estimating both stress and fault plane is developed by Vavryĉuk in 2014. The fault orientations are determined by applying the fault instability constraint, and the stress is calculated in iterations. In this study, this method is applied to a high-density earthquake regions, Simeulue-Batu Island. This area is interesting to be investigated because of the occurrence of the two large earthquakes, i.e. Aceh 2004 and Nias 2005 earthquake. The inversion was done based on 343 focal mechanisms data with Magnitude ≥5.5 Mw between 25th Mei 1977- 25th August 2015 from Harvard and Global Centroid Moment Tensor (GCMT) catalog. The area is divided into some grids, in which the analysis of stress orientation variation and its shape ratio is done for each grid. Stress inversion results show that there are three segments along Simeulue-Batu Island based on the variation of orientation stress σ1. The stress characteristics of each segments are discussed, i.e. shape ratio, principal stress orientation and subduction angle. Interestingly, the highest value of shape ratio is 0.93 and its association with the large earthquake Aceh 2004. This suggest that the zonation obtained in this study could also be used as a proxy for the hazard map.

Ecosystem health in mineralized terrane; data from podiform chromite (Chinese Camp mining district, California), quartz alunite (Castle Peak and Masonic mining districts, Nevada/California), and Mo/Cu porphyry (Battle Mountain mining district, Nevada) deposits

USGS Publications Warehouse

Blecker, Steve W.; Stillings, Lisa L.; Amacher, Michael C.; Ippolito, James A.; DeCrappeo, Nicole M.

2010-01-01

within various mineralized terranes. We were also interested in examining these relations in the context of determining appropriate reference conditions with which to compare reclamation efforts.The purpose of this report is to present the data used to develop indices of soil and ecosystem quality associated with mineralized terranes (areas enriched in metal-bearing minerals), specifically podiform chromite, quartz alunite, and Mo/Cu porphyry systems. Within each of these mineralized terranes, a nearby unmineralized counterpart was chosen for comparison. The data consist of soil biological, chemical, and physical parameters, along with vegetation measurements for each of the sites described below. Synthesis of these data and index development will be the subject of future publications.

Magmatic-hydrothermal origin of the early Triassic Laodou lode gold deposit in the Xiahe-Hezuo district, West Qinling orogen, China: implications for gold metallogeny

NASA Astrophysics Data System (ADS)

Jin, Xiao-ye; Li, Jian-wei; Hofstra, Albert H.; Sui, Ji-xiang

2017-08-01

The Xiahe-Hezuo district in the West Qinling orogen contains numerous Au-(As-Sb) and Cu-Au-(W) deposits. The district is divided into eastern and western zones by the Xiahe-Hezuo Fault. The western zone is exposed at a shallow level and contains sediment-hosted disseminated Au-(As-Sb) deposits, whereas the eastern zone is exposed at a deeper level and contains Cu-Au-(W) skarn and lode gold deposits within or close to granitic intrusions. The Laodou gold deposit in the eastern zone consists of auriferous quartz-sulfide-tourmaline and minor quartz-stibnite veins that are structurally controlled by fault zones transecting the Laodou quartz diorite porphyry stock and enveloped by potassic and phyllic alteration. Both the veins and alteration halos commonly contain quartz, sericite, tourmaline, pyrite, and arsenopyrite, with minor galena, sphalerite, chalcopyrite, tetrahedrite, and enargite. Gold occurs mainly as invisible gold in pyrite or arsenopyrite and locally as inclusions less than 50 μm in diameter. The zircon U-Pb age of 247.6 ± 1.3 Ma (2 σ) on the host quartz diorite porphyry and the sericite 40Ar/39Ar plateau ages of 249.1 ± 1.6 and 249.0 ± 1.5 Ma (2 σ) on two ore-related hydrothermal sericite samples are within analytical errors of one another. At the formation temperature (275 °C) inferred from microthermometric measurements of fluid inclusion, sericite and tourmaline yield calculated δDH2O values of -70 to -45‰ and δ 18OH2O of 5.8 to 9.7‰, while quartz yields calculated δ 18OH2O values of 5.1˜5.7‰. Hydrothermal tourmaline in quartz-sulfide-tourmaline veins has δ 11B of -11.2 to -0.9‰ (mean of -6.3‰) that are similar to the values of magmatic tourmaline (-8.9 to -5.5‰ with a mean of -6.8‰) in the host quartz diorite porphyry. The δ 34S values of sulfide minerals range from -5.9 to +5.8‰ with a mean of -0.6‰ that is typical of magmatic sulfur. Pyrite from hydrothermally altered quartz diorite porphyry and quartz

New Mexico structural zone - An analogue of the Colorado mineral belt

USGS Publications Warehouse

Sims, P.K.; Stein, H.J.; Finn, C.A.

2002-01-01

Updated aeromagnetic maps of New Mexico together with current knowledge of the basement geology in the northern part of the state (Sangre de Cristo and Sandia-Manzano Mountains)-where basement rocks were exposed in Precambrian-cored uplifts-indicate that the northeast-trending Proterozoic shear zones that controlled localization of ore deposits in the Colorado mineral belt extend laterally into New Mexico. The shear zones in New Mexico coincide spatially with known epigenetic precious- and base-metal ore deposits; thus, the mineralized belts in the two states share a common inherited basement tectonic setting. Reactivation of the basement structures in Late Cretaceous-Eocene and Mid-Tertiary times provided zones of weakness for emplacement of magmas and conduits for ore-forming solutions. Ore deposits in the Colorado mineral belt are of both Late Cretaceous-Eocene and Mid-Tertiary age; those in New Mexico are predominantly Mid-Tertiary in age, but include Late Cretaceous porphyry-copper deposits in southwestern New Mexico. The mineralized belt in New Mexico, named the New Mexico structural zone, is 250-km wide. The northwest boundary is the Jemez subzone (or the approximately equivalent Globe belt), and the southeastern boundary was approximately marked by the Santa Rita belt. Three groups (subzones) of mineral deposits characterize the structural zone: (1) Mid-Tertiary porphyry molybdenite and alkaline-precious-metal deposits, in the northeast segment of the Jemez zone; (2) Mid-Tertiary epithermal precious-metal deposits in the Tijeras (intermediate) zone; and (3) Late Cretaceous porphyry-copper deposits in the Santa Rita zone. The structural zone was inferred to extend from New Mexico into adjacent Arizona. The structural zone provides favorable sites for exploration, particularly those parts of the Jemez subzone covered by Neogene volcanic and sedimentary rocks. ?? 2002 Published by Elsevier Science B.V.

Visualizing trace element distribution in quartz using cathodoluminescence, electron microprobe, and laser ablation-inductively coupled plasma-mass spectrometry

USGS Publications Warehouse

Rusk, Brian; Koenig, Alan; Lowers, Heather

2011-01-01

Cathodoluminescent (CL) textures in quartz reveal successive histories of the physical and chemical fluctuations that accompany crystal growth. Such CL textures reflect trace element concentration variations that can be mapped by electron microprobe or laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Trace element maps in hydrothermal quartz from four different ore deposit types (Carlin-type Au, epithermal Ag, porphyry-Cu, and MVT Pb-Zn) reveal correlations among trace elements and between trace element concentrations and CL textures. The distributions of trace elements reflect variations in the physical and chemical conditions of quartz precipitation. These maps show that Al is the most abundant trace element in hydrothermal quartz. In crystals grown at temperatures below 300 °C, Al concentrations may vary by up to two orders of magnitude between adjacent growth zones, with no evidence for diffusion. The monovalent cations Li, Na, and K, where detectable, always correlate with Al, with Li being the most abundant of the three. In most samples, Al is more abundant than the combined total of the monovalent cations; however, in the MVT sample, molar Al/Li ratios are ~0.8. Antimony is present in concentrations up to ~120 ppm in epithermal quartz (~200–300 °C), but is not detectable in MVT, Carlin, or porphyry-Cu quartz. Concentrations of Sb do not correlate consistently with those of other trace elements or with CL textures. Titanium is only abundant enough to be mapped in quartz from porphyry-type ore deposits that precipitate at temperatures above ~400 °C. In such quartz, Ti concentration correlates positively with CL intensity, suggesting a causative relationship. In contrast, in quartz from other deposit types, there is no consistent correlation between concentrations of any trace element and CL intensity fluctuations.

LA-ICP-MS Dating and Tectonic Setting of Yeba Formation Lavas in Qulong Area east Part of the Gangdise Belt, Xizang China

NASA Astrophysics Data System (ADS)

Liu, D.

2009-12-01

In China, Xizang Gangdise tectonic belt is a large nonferrous metal and noble metal mineralized zone and in which, it is found that the mineralization correlates with Tethyan Ocean subduction, continent-continent collision and magmatism due to inter-continent extension orogeny. Qulong porphyry copper (molybdenum) deposit is the largest recently found in the Gangdise metallogenic belt and is one of the most large porphyry copper deposit in Asia. In the area of Qulong porphyry copper deposit, the adjacent strata is Yeba Formation and which can be parted into three members. The first member is built up of dacite, rhyolite, andesite, lapilli tuff, volcanic breccia and volcanic agglomerate. The second member widely occur in the area with major rocks of medium-acidic lava, debris-crystallinoclastic volcanic tuff intercalated with tuffaceous sand, tuffaceous slate and limestone. The third member is built up of andesite, liparite, crystallinoclastic tuff intercalated with sillicalite, sericite slate, tuffaceous sandstone and dirty limestone. The volcanic tuff in the second member gives a LA-ICP-MS U-Pb zircon age of 156.2±2.3 Ma, which may represent the age of the Yeba Formation. That is to say, in the study area, the Yeba Formation comes to being in age of Middle and Later Jurassic. The characteristic which comes from the research on geochronology and rockassociations suggests that the Yeba Formation volcanic rocks are built up by a long time ejection and the ejection of the Yeba Formation volcanic rocks comes from west to east in the Gangdise zone. The volcanic rocks in the Yeba Formation can be considered as the products originated from northward subduction and consumption of the Tethyan Ocean. At the same time, it is proposed that the Yeba Formation volcanic rocks have potential significances in evaluating the early Jurassic biotic crisis, climate change, regression or intrusion event and the later mineralizaion.

Variscan potassic dyke magmatism of durbachitic affinity at the southern end of the Bohemian Massif (Lower Austria)

NASA Astrophysics Data System (ADS)

Zeitlhofer, Helga; Grasemann, Bernhard; Petrakakis, Konstantin

2016-06-01

Dykes in the Strudengau area (SW Moldanubian Zone, Austria) can be mineralogically divided into lamprophyres (spessartites and kersantites) and felsic dykes (granite porphyries, granitic dykes and pegmatoid dykes). Geochemical analyses of 11 lamprophyres and 7 felsic dykes show evidence of fractional crystallization. The lamprophyres are characterized by metaluminous compositions, intermediate SiO2 contents and high amounts of MgO and K2O; these rocks have high Ba (800-3000 ppm) and Sr (250-1000 ppm) contents as well as an enrichment of large-ion lithophile elements over high field strength elements, typical for enriched mantle sources with variable modifications due to fractionation and crustal contamination. This geochemical signature has been reported from durbachites (biotite- and K feldspar-rich mela-syenites particularly characteristic of the Variscan orogen in Central Europe). For most major elements, calculated fractionation trends from crystallization experiments of durbachites give an excellent match with the data from the Strudengau dykes. This suggests that the lamprophyres and felsic dykes were both products of fractional crystallization and subsequent magma mixing of durbachitic and leucogranitic melts. Rb-Sr geochronological data on biotite from five undeformed kersantites and a locally deformed granite porphyry gave cooling ages of c. 334-318 Ma, indicating synchronous intrusion of the dykes with the nearby outcropping Weinsberger granite (part of the South Bohemian Batholith, c. 330-310 Ma). Oriented matrix biotite separated from the locally deformed granite porphyry gave an Rb-Sr age of c. 318 Ma, interpreted as a deformation age during extensional tectonics. We propose a large-scale extensional regime at c. 320 Ma in the Strudengau area, accompanied by plutonism of fractionated magmas of syncollisional mantle-derived sources, mixed with crustal components. This geodynamic setting is comparable to other areas in the Variscan belt documenting an

Characteristics of the Late Devonian Tsagaan Suvarga Cu-Mo deposit, Southern Mongolia

NASA Astrophysics Data System (ADS)

Tungalag, Naidansuren; Jargalan, Sereenen; Khashgerel, Bat-Erdene; Mijiddorj, Chuluunbaatar; Kavalieris, Imants

2018-05-01

The Late Devonian Tsagaan Suvarga deposit (255 Mt at 0.55% Cu, 0.02% Mo) is located on the NW margin of the Tsagaan Suvarga Complex (TSC), which extends ENE over 15 × 10 km and comprises mainly medium-grained equigranular hornblende-biotite quartz monzonite and monzodiorite. Distinct mineralized intrusions are inferred from distribution of Cu-Mo mineralization but are not clearly discernible. The Tsagaan Suvarga Complex is a window within Carboniferous volcanic and sedimentary rocks, and wall rocks to the TSC are not known or exposed in the nearby district. Whole-rock analyses and Sr-Nd isotopes, 87Sr/86Sr0 = 0.7027 to 0.7038 (n = 12) and ɛNd0 = + 4.26 to + 2.77 (n = 12), show that the granitoids are subduction-related I-type, high K-calc-alkaline to shoshonitic series and derived from a mantle source. They exhibit fractionated light rare earth elements, without depleted Eu and depleted middle heavy rare earth elements and Y, typical of oxidized, fertile porphyry magmatic suites. Early porphyry-style quartz veins include A- and B-type. Molybdenite occurs in monomineralic veins (1-5 mm) or A veins. Copper mineralization occurs mainly as chalcopyrite and subordinate bornite, disseminated and associated with quartz-muscovite veins. Pyrite (vol%) content is less than chalcopyrite and bornite combined. Deep oxidation to about 50 m depth has formed zones of malachite and covellite in late fractures. The most important alteration is actinolite-biotite-chlorite-magnetite replacing hornblende and primary biotite. Quartz-K-feldspar alteration is minor. Late albite replaces primary K-feldspar and enhances sodic rims on plagioclase crystals. Quartz-muscovite (or sericitic alteration) overprints actinolite-biotite and porphyry-type quartz veins. Field observations and petrographic studies suggest that the bulk of the chalcopyrite-bornite mineralization at the Tsagaan Suvarga formed together with coarse muscovite alteration.

Noble gas data from Goldfield and Tonopah epithermal Au-Ag deposits, ancestral Cascades Arc, USA: Evidence for a primitive mantle volatile source

USGS Publications Warehouse

Manning, Andrew H.; Hofstra, Albert H.

2017-01-01

The He, Ne, and Ar isotopic composition of fluid inclusions in ore and gangue minerals were analyzed to determine the source of volatiles in the high-grade Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada, USA. Ar and Ne are mainly atmospheric, whereas He has only a minor atmospheric component. Corrected 3He/4He ratios (with atmospheric He removed) range widely from 0.05 to 35.8 times the air 3He/4He ratio (RA), with a median of 1.43 RA. Forty-one percent of measured 3He/4He ratios are ≥4 RA, corresponding to ≥50% mantle He assuming a mantle ratio of 8 RA. These results suggest that mafic magmas were part of the magmatic-hydrothermal system underlying Goldfield and Tonopah, and that associated mantle-sourced volatiles may have played a role in ore formation. The three highest corrected 3He/4He ratios of 17.0, 23.7, and 35.8 RAindicate a primitive mantle He source and are the highest yet reported for any epithermal-porphyry system and for the Cascades arc region. Compiled 3He/4He measurements from epithermal-porphyry systems in subduction-related magmatic arcs around the world (n = 209) display a statistically significant correlation between 3He/4He and Au-Ag grade. The correlation suggests that conditions which promote higher fluid inclusion 3He/4He ratios (abundance of mantle volatiles and focused upward volatile transport) have some relation to conditions that promote higher Au-Ag grades (focused flow of metal-bearing fluids and efficient chemical traps). Results of this and previous investigations of He isotopes in epithermal-porphyry systems are consistent with the hypothesis posed in recent studies that mafic magmas serve an important function in the formation of these deposits.

Mechanical Damage Detection of Indonesia Local Citrus Based on Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Siregar, T. H.; Ahmad, U.; Sutrisno; Maddu, A.

2018-05-01

Citrus experienced physical damage in peel will produce essential oils that contain polymethoxylated flavone. Polymethoxylated flavone is fluorescence substance; thus can be detected by fluorescence imaging. This study aims to study the fluorescence spectra characteristic and to determine the damage region in citrus peel based on fluorescence image. Pulung citrus from Batu district, East Java, as a famous citrus production area in Indonesia, was used in the experiment. It was observed that the image processing could detect the mechanical damage region. Fluorescence imaging can be used to classify the citrus into two categories, sound and defect citruses.

Tracking rare orchids (Orchidaceae) in Arizona

Treesearch

Ronald A. Coleman

2001-01-01

Twenty-six native orchid species occur in Arizona, and 14 are considered rare with fewer than 100 occurrences in the state. The author is conducting three studies covering four of the wild orchids: Stenorrhynchos michuacanum, Hexalectris revoluta, Malaxis porphyry, and M. tenuis. The studies are ongoing so only interim results are available. Interim results indicate...

Utility of high-altitude infrared spectral data in mineral exploration: Application to Northern Patagonia Mountains, Arizona

USGS Publications Warehouse

Berger, B.R.; King, T.V.V.; Morath, L.C.; Phillips, J.D.

2003-01-01

Synoptic views of hydrothermal alteration assemblages are of considerable utility in regional-scale minerals exploration. Recent advances in data acquisition and analysis technologies have greatly enhanced the usefulness of remotely sensed imaging spectroscopy for reliable alteration mineral assemblages mapping. Using NASA's Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, this study mapped large areas of advanced argillic and phyllic-argillic alteration assemblages in the southeastern Santa Rita and northern Patagonia mountains, Arizona. Two concealed porphyry copper deposits have been identified during past exploration, the Red Mountain and Sunnyside deposits, and related published hydrothermal alteration zoning studies allow the comparison of the results obtained from AVIRIS data to the more traditional field mapping approaches. The AVIRIS mapping compares favorably with field-based studies. An analysis of iron-bearing oxide minerals above a concealed supergene chalcocite deposit at Red Mountain also indicates that remotely sensed data can be of value in the interpretation of leached caps above porphyry copper deposits. In conjunction with other types of geophysical data, AVIRIS mineral maps can be used to discriminate different exploration targets within a region.

Discrimination of hydrothermally altered rocks along the Battle Mountain-Eureka, Nevada mineral belt using LANDSAT images

NASA Technical Reports Server (NTRS)

Krohn, M. D.; Abrams, M. J.; Rowan, L. C. (Principal Investigator)

1979-01-01

The author has identified the following significant results. Limonitic alteration halos associated with two copper prophyry deposits were successfully mapped at Battle Mountain. Alteration halos from both a hypogene system at Copper Canyon and a supergene system at Copper Basin are recognizable in the composite. Both copper porphyry deposits are located in sedimentary rock units that commonly have ferruginous coatings; yet, in most cases, the hydrothermally derived limonite was distinguishable in the CRC from sedimentary limonite. Large format playback images with pixel sizes from 200 to 400 micron m provided details of spatial resolution and color separation unachievable on enlargements from 70 mm film chips. Details of the alteration halos could be resolved only in the large format images. Two aspects of the alteration halos of the porphyry copper deposits were not mapped on the CRC. The optimum CRC image for the area studied consists of MSS 4/5 as blue, MSS 4/6 as yellow, and MSS 6/7 as magenta using diazo films. The disseminated gold deposits at Gold Acres are not depicted in the CRC image.

Trace elements in hydrothermal quartz: Relationships to cathodoluminescent textures and insights into vein formation

USGS Publications Warehouse

Rusk, B.G.; Lowers, H.A.; Reed, M.H.

2008-01-01

High-resolution electron microprobe maps show the distribution of Ti, Al, Ca, K, and Fe among quartz growth zones revealed by scanning electron microscope-cathodoluminescence (SEM-CL) from 12 hydrothermal ore deposits formed between ???100 and e1750 ??C. The maps clearly show the relationships between trace elements and CL intensity in quartz. Among all samples, no single trace element consistently correlates with variations in CL intensity. However in vein quartz from five porphyry-Cu (Mo-Au) deposits, CL intensity always correlates positively with Ti concentrations, suggesting that Ti is a CL activator in quartz formed at >400 ??C. Ti concentrations in most rutile-bearing vein quartz from porphyry copper deposits indicate reasonable formation temperatures of 2000 ppm, but in high-temperature quartz, Al concentrations are consistently in the range of several hundred ppm. Aluminum concentrations in quartz refl ect the Al solubility in hydrothermal fluids, which is strongly dependent on pH. Aluminum concentrations in quartz therefore reflect fluctuations in pH that may drive metal-sulfide precipitation in hydrothermal systems. ?? 2008 The Geological Society of America.

The formation age of ores from the Pebble Cu-Au-Mo giant deposit (Alaska, United States)

NASA Astrophysics Data System (ADS)

Kremenetskii, A. A.; Popov, V. S.; Gromalova, N. A.

2012-02-01

Zircons from the porphyry-like quartz-diorite boss of the Pebble Cu-Au-Mo deposit (southwest Alaska) have been examined. By their appearance and internal structure (cathode luminescence and electron probing), the zircons have been subdivided into four genetic groups: (1) xenogenic detrital (mainly rounded); (2) magmatogene (protolith crystal in the center and growth zone at the edge); (3) hydrothermally altered (with new-formed regeneration edges in growth zones); (4) metamict-altered (unconsolidated center of the crystal and sectoring in growth zones). Based on SHRIMP U-Pb dating for the principal heterogeneous elements in every group, the following stages of ore formation have been identified for the Pebble deposit: (a) crystallization of quartz diorite-porphyry bosses (95-92 Ma, the concordant age is 94.7 ± 1.5 Ma); (b) late magmatic metasomatic alterations with copper-molybdenum mineralization (92-85 Ma, the concordant age is 90.15 ± 0.78 Ma); (c) postmagmatic argillization with epithermal gold-sulfide mineralization (82-80 Ma, the concordant age is 82.9 ± 2.7 Ma).

Factors Affecting Road Traffic Accident in Batu Pahat, Johor, Malaysia

NASA Astrophysics Data System (ADS)

Che-Him, Norziha; Roslan, Rozaini; Saifullah Rusiman, Mohd; Khalid, Kamil; Ghazali Kamardan, M.; Azbi Arobi, Farquis; Mohamad, Nazeera

2018-04-01

A road traffic accident resulted from the combination of factors related to the few components of the system involving environment, roads, road users, vehicles and the interaction between those systems. Road traffic accident (RTA) in Malaysia recorded as the highest fatality rate (per 100,000 population) among the ASEAN countries. In 2016, more than half of million cases accident recorded with more than 7,000 people were killed. Therefore, the RTA is one of the most critical issue in Malaysia even become the worldwide burden to authority. Generally, driving is a complex process which involves movement of a vehicle by either a computer or human controller. However, failure to control and coordinate will contribute to an accident. The objective of this study is to identify the pattern of accident in Johor Malaysia and to examine the relationship between the number of accident and the types of vehicles and roads. The results could help the government to recognise the different patterns, types of vehicles and roads that show major factors in the increasing of road traffic accident in Malaysia.

Rhenium: a rare metal critical in modern transportation

USGS Publications Warehouse

John, David A.

2015-01-01

Rhenium rarely occurs as a native element or as its own sulfide mineral—rheniite (ReS2)—and often occurs as a substitute for molybdenum in molybdenite (MoS2). Most extracted rhenium is a byproduct of copper mining, with about 80 percent recovered from flue dust during the processing of molybdenite concentrates from porphyry copper deposits.

Are fractal dimensions of the spatial distribution of mineral deposits meaningful?

USGS Publications Warehouse

Raines, G.L.

2008-01-01

It has been proposed that the spatial distribution of mineral deposits is bifractal. An implication of this property is that the number of deposits in a permissive area is a function of the shape of the area. This is because the fractal density functions of deposits are dependent on the distance from known deposits. A long thin permissive area with most of the deposits in one end, such as the Alaskan porphyry permissive area, has a major portion of the area far from known deposits and consequently a low density of deposits associated with most of the permissive area. On the other hand, a more equi-dimensioned permissive area, such as the Arizona porphyry permissive area, has a more uniform density of deposits. Another implication of the fractal distribution is that the Poisson assumption typically used for estimating deposit numbers is invalid. Based on datasets of mineral deposits classified by type as inputs, the distributions of many different deposit types are found to have characteristically two fractal dimensions over separate non-overlapping spatial scales in the range of 5-1000 km. In particular, one typically observes a local dimension at spatial scales less than 30-60 km, and a regional dimension at larger spatial scales. The deposit type, geologic setting, and sample size influence the fractal dimensions. The consequence of the geologic setting can be diminished by using deposits classified by type. The crossover point between the two fractal domains is proportional to the median size of the deposit type. A plot of the crossover points for porphyry copper deposits from different geologic domains against median deposit sizes defines linear relationships and identifies regions that are significantly underexplored. Plots of the fractal dimension can also be used to define density functions from which the number of undiscovered deposits can be estimated. This density function is only dependent on the distribution of deposits and is independent of the

Mineralogical and Geochemical Study of Titanite Associated With Copper Mineralization in the Hopper Property, Yukon Territory, Canada

NASA Astrophysics Data System (ADS)

Blumenthal, V. H.; Linnen, R. L.

2009-05-01

Copper mineralization in central Yukon is well known, but the metallogeny of the Ruby Range batholith, west of the copper belt, is poorly understood. The Hopper property, situated in the south western part of the Yukon in the Yukon-Tanana terrane, contains copper mineralization hosted by granodiorite and quartz feldspar porphyry of cal-alkaline affinity. These rock units, interpreted to be part of the Ruby Range batholith, intruded metasediments of the Ashihik Metamorphic Suite rocks. Mafic dykes cross cut the intrusion followed by aplite dykes. Small occurrences of skarn also occur in the area and some of these contain copper mineralization. The copper mineralization at the Hopper property appears to have a porphyry-type affinity. However, it is associated with a shear zone and propylitic alteration unlike other typical copper porphyry-type deposits. This raises the question whether or not the mineralization is orthomagmatic in origin, i.e., whether or not this is a true porphyry system. The main zone of mineralization is 1 kilometer long and 0.5 kilometer wide. It is characterized by disseminated chalcopyrite and pyrite, which also occur along fractures. Molybdenite mineralization was found to be associated with slickensides. Alteration minerals associated with the copper mineralization are chlorite, epidote-clinozoisite, carbonate and titanite. Chlorite and epidote-clinozoisite are concentrated in the mineralized zone, whereas an earlier potassic alteration shows a weaker spatial correlation with the mineralization. The association of the mineralization with propylitic alteration leads us to believe the mineralization is shear related, although a deeper porphyritic system may be present at depth. Two populations of titanite at the Hopper property are recognized based on their shape, size and association with other minerals. The first population, defined by a length of 100 micrometers to 1 centimeter, euhedral boundaries, and planar contacts with other magmatic

Lead-isotopic, sulphur-isotopic, and trace-element studies of galena from the Silesian-Cracow Zn-Pb ores, polymetallic veins from the Gory Swietokrzyskie MTS, and the Myszkow porphyry copper deposit, Poland

USGS Publications Warehouse

Church, S.E.; Vaughn, R.B.; Gent, C.A.; Hopkins, R.T.

1996-01-01

Lead-isotopic data on galena samples collected from a paragenetically constrained suite of samples from the Silesian-Cracow ore district show no regional or paragenetically controlled lead-isotopic trends within the analytical reproducibility of the measurements. Furthermore, the new lead-isotopic data agree with previously reported lead-isotopic results (R. E. Zartman et al., 1979). Sulfur-isotopic analyses of ores from the Silesian-Cracow district as well as from vein ore from the Gory Swietokrzyskie Mts. and the Myszkow porphyry copper deposit, when coupled with trace-element data from the galena samples, clearly discriminate different hydrothermal ore-forming events. Lead-isotopic data from the Permian and Miocene evaporite deposits in Poland indicate that neither of these evaporite deposits were a source of metals for the Silesian-Cracow district ores. Furthermore, lead-isotopic data from these evaporite deposits and the shale residues from the Miocene halite samples indicate that the crustal evolution of lead in the central and western European platform in southern Poland followed normal crustal lead-isotopic growth, and that the isotopic composition of crustal lead had progressed beyond the lead-isotopic composition of lead in the Silesian-Cracow ores by Permian time. Thus, Mesozoic and Tertiary sedimentary flysch rocks can be eliminated as viable source rocks for the metals in the Silesian-Cracow Mississippi Valley-type (MVT) deposits. The uniformity of the isotopic composition of lead in the Silesian-Cracow ores, when coupled with the geologic evidence that mineralization must post-date Late Jurassic faulting (E. Gorecka, 1991), constrains the geochemical nature of the source region. The source of the metals is probably a well-mixed, multi-cycle molasse sequence of sedimentary rocks that contains little if any Precambrian metamorphic or granitic clasts (S. E. Church, R. B. Vaughn, 1992). If ore deposition was post Late Jurassic (about 150 m. y.) or later

A Study of Flood Evacuation Center Using GIS and Remote Sensing Technique

NASA Astrophysics Data System (ADS)

Mustaffa, A. A.; Rosli, M. F.; Abustan, M. S.; Adib, R.; Rosli, M. I.; Masiri, K.; Saifullizan, B.

2016-07-01

This research demonstrated the use of Remote Sensing technique and GIS to determine the suitability of an evacuation center. This study was conducted in Batu Pahat areas that always hit by a series of flood. The data of Digital Elevation Model (DEM) was obtained by ASTER database that has been used to delineate extract contour line and elevation. Landsat 8 image was used for classification purposes such as land use map. Remote Sensing incorporate with GIS techniques was used to determined the suitability location of the evacuation center from contour map of flood affected areas in Batu Pahat. GIS will calculate the elevation of the area and information about the country of the area, the road access and percentage of the affected area. The flood affected area map may provide the suitability of the flood evacuation center during the several levels of flood. The suitability of evacuation centers can be determined based on several criteria and the existing data of the evacuation center will be analysed. From the analysis among 16 evacuation center listed, there are only 8 evacuation center suitable for the usage during emergency situation. The suitability analysis was based on the location and the road access of the evacuation center toward the flood affected area. There are 10 new locations with suitable criteria of evacuation center proposed on the study area to facilitate the process of rescue and evacuating flood victims to much safer and suitable locations. The results of this study will help in decision making processes and indirectly will help organization such as fire-fighter and the Department of Social Welfare in their work. Thus, this study can contribute more towards the society.

Flood Water Level Mapping and Prediction Due to Dam Failures

NASA Astrophysics Data System (ADS)

Musa, S.; Adnan, M. S.; Ahmad, N. A.; Ayob, S.

2016-07-01

Sembrong dam has undergone overflow failure. Flooding has been reported to hit the town, covering an area of up to Parit Raja, located in the district of Batu Pahat. This study aims to identify the areas that will be affected by flood in the event of a dam failure in Sembrong Dam, Kluang, Johor at a maximum level. To grasp the extent, the flood inundation maps have been generated by using the InfoWorks ICM and GIS software. By using these maps, information such as the depth and extent of floods can be identified the main ares flooded. The flood map was created starting with the collection of relevant data such as measuring the depth of the river and a maximum flow rate for Sembrong Dam. The data were obtained from the Drainage and Irrigation Department Malaysia and the Department of Survey and Mapping and HLA Associates Sdn. Bhd. Then, the data were analyzed according to the established Info Works ICM method. The results found that the flooded area were listed at Sri Lalang, Parit Sagil, Parit Sonto, Sri Paya, Parit Raja, Parit Sempadan, Talang Bunut, Asam Bubok, Tanjung Sembrong, Sungai Rambut and Parit Haji Talib. Flood depth obtained for the related area started from 0.5 m up to 1.2 m. As a conclusion, the flood emanating from this study include the area around the town of Ayer Hitam up to Parit Raja approximately of more than 20 km distance. This may give bad implication to residents around these areas. In future studies, other rivers such as Sungai Batu Pahat should be considered for this study to predict and reduce the yearly flood victims for this area.

Structural controls on Eocene to Pliocene tectonic and metallogenic evolution of the southernmost Lesser Caucasus, Armenia: paleostress field reconstruction and fault-slip analysis

NASA Astrophysics Data System (ADS)

Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik

2017-04-01

The Cenozoic evolution of the central segment of the Tethyan belt is dominated by oblique convergence and final collision of Gondwana-derived terranes and the Arabian plate with Eurasia, which created a favorable setting for the formation of the highly mineralized Meghri-Ordubad pluton in the southernmost Lesser Caucasus. Regional strike-slip faults played an important role in the control of the porphyry Cu-Mo and epithermal systems hosted by the Meghri-Ordubad pluton. In this contribution we discuss the paleostress and the kinematic environment of the major strike-slip and oblique-slip ore-controlling faults throughout the Eocene subduction to Mio-Pliocene post-collisional tectonic evolution of the Meghri-Ordubad pluton based on detailed structural field mapping of the ore districts, stereonet compilation of ore-bearing fractures and vein orientations in the major porphyry and epithermal deposits, and the paleostress reconstructions. Paleostress reconstructions indicate that during the Eocene and Early Oligocene, the main paleostress axe orientations reveal a dominant NE-SW-oriented compression, which is compatible with the subduction geometry of the Neotethys along Eurasia. This tectonic setting was favorable for dextral displacements along the two major, regional NNW-oriented Khustup-Giratakh and Salvard-Ordubad strike-slip faults. This resulted in the formation of a NS-oriented transrotational basin, known as the Central magma and ore- controlling zone (Tayan, 1998). It caused a horizontal clockwise rotation of blocks. The EW-oriented faults separating the blocks formed as en-échelon antithetic faults (Voghji, Meghrasar, Bughakyar and Meghriget-Cav faults). The Central zone consists of a network of EW-oriented sinistral and NS-oriented subparallel strike-slip faults (Tashtun, Spetry, Tey, Meghriget and Terterasar faults). They are active since the Eocene and were reactivated during the entire tectonic evolution of the pluton, but with different behaviors

Petrologic, tectonic, and metallogenic evolution of the southern segment of the ancestral Cascades magmatic arc, California and Nevada

USGS Publications Warehouse

du Bray, Edward A.; John, David A.; Cousens, Brian L.

2013-01-01

Although rocks in the two arc segments have similar metal abundances, they are metallogenically distinct. Small porphyry copper deposits are characteristic of the northern segment whereas significant epithermal precious metal deposits are most commonly associated with the southern segment. These metallogenic differences are also fundamentally linked to the tectonic settings and crustal regimes within which these two arc segments evolved.

Landsat-D TM application to porphyry copper exploration

NASA Technical Reports Server (NTRS)

Abrams, M.; Brown, D.; Sadowski, R.; Lepley, L.

1982-01-01

For a number of years Landsat data have been used to locate areas of iron oxide occurrences which might be associated with hydrothermal alteration zones. However, the usefulness of the Landsat data was restricted because of certain limitations of the spectral information provided by Landsat. A new generation multispectral scanner will, therefore, be carried by the fourth Landsat, which is to be launched in July, 1982. This instrument, called the Thematic Mapper (TM), will have seven channels and provide data with 30 m spatial resolution. Two of the spectral channels (1.6 micron and 2.2 micron) should allow detection of hydrous minerals. Possible applications of Landsat-D TM data for copper exploration were studied on the basis of a comparison of Landsat data with simulated TM data acquired using an aircraft scanner instrument. Three porphyr copper deposits in Arizona were selected for the study. It is concluded that the new Landsat-D TM scanner will provide Exploration geologists with a new improved tool for surveying mineral resources on a global basis.

Pre-eruptive conditions of the Hideaway Park topaz rhyolite: Insights into metal source and evolution of magma parental to the Henderson porphyry molybdenum deposit, Colorado

USGS Publications Warehouse

Mercer, Celestine N.; Hofstra, Albert H.; Todorov, Todor I.; Roberge, Julie; Burgisser, Alain; Adams, David T.; Cosca, Michael A.

2015-01-01

The Hideaway Park tuff is the only preserved extrusive volcanic unit related to the Red Mountain intrusive complex, which produced the world-class Henderson porphyry Mo deposit. Located within the Colorado Mineral Belt, USA, Henderson is the second largest Climax-type Mo deposit in the world, and is therefore an excellent location to investigate magmatic processes leading to Climax-type Mo mineralization. We combine an extensive dataset of major element, volatile, and trace element abundances in quartz-hosted melt inclusions and pumice matrix glass with major element geochemistry from phenocrysts to reconstruct the pre-eruptive conditions and the source and evolution of metals within the magma. Melt inclusions are slightly peraluminous topaz rhyolitic in composition and are volatile-charged (≤6 wt % H2O, ≤600 ppm CO2, ∼0·3–1·0 wt % F, ∼2300–3500 ppm Cl) and metal-rich (∼7–24 ppm Mo, ∼4–14 ppm W, ∼21–52 ppm Pb, ∼28–2700 ppm Zn, <0·1–29 ppm Cu, ∼0·3–1·8 ppm Bi, ∼40–760 ppb Ag, ∼690–1400 ppm Mn). Melt inclusion and pumice matrix glass chemistry reveal that the Hideaway Park magma evolved by large degrees of fractional crystallization (≤60–70%) during quartz crystallization and melt inclusion entrapment at pressures of ≤300 MPa (≤8 km depth), with little to no crystallization upon shallow ascent and eruption. Filter pressing, crystal settling, magma recharge and mixing of less evolved rhyolite melt, and volatile exsolution were important processes during magma evolution; the low estimated viscosities (∼105–1010 Pa s) of these H2O- and F-rich melts probably enhanced these processes. A noteworthy discrepancy between the metal contents in the pumice matrix glass and in the melt inclusions suggests that after quartz crystallization ceased upon shallow magma ascent and eruption, the Hideaway Park magma exsolved an aqueous fluid into which Mo, Bi, Ag, Zn, Mn, Cs, and Y strongly

Late paleozoic base and precious metal deposits, East Tianshan, Xinjiang, China: Characteristics and geodynamic setting

USGS Publications Warehouse

Mao, J.; Goldfarb, R.J.; Wang, Y.; Hart, C.J.; Wang, Z.; Yang, J.

2005-01-01

The East Tianshan is a remote Gobi area located in eastern Xinjiang, northwestern China. In the past several years, a number of gold, porphyry copper, and Fe(-Cu) and Cu-Ag-Pb-Zn skarn deposits have been discovered there and are attracting exploration interest. The East Tianshan is located between the Junggar block to the north and early Paleozoic terranes of the Middle Tianshan to the south. It is part of a Hercynian orogen with three distinct E-W-trending tectonic belts: the Devonian-Early Carboniferous Tousuquan-Dananhu island arc on the north and the Carboniferous Aqishan - Yamansu rift basin to the south, which are separated by rocks of the Kanggurtag shear zone. The porphyry deposits, dated at 322 Ma, are related to the late evolutionary stages of a subduction-related oceanic or continental margin arc. In contrast, the skarn, gold, and magmatic Ni-Cu deposits are associated with post-collisional tectonics at ca. 290-270 Ma. These Late Carboniferous - Early Permian deposits are associated with large-scale emplacement and eruption of magmas possibly caused by lithosphere delamination and rifting within the East Tianshan.

Statistical methods of estimating mining costs

USGS Publications Warehouse

Long, K.R.

2011-01-01

Until it was defunded in 1995, the U.S. Bureau of Mines maintained a Cost Estimating System (CES) for prefeasibility-type economic evaluations of mineral deposits and estimating costs at producing and non-producing mines. This system had a significant role in mineral resource assessments to estimate costs of developing and operating known mineral deposits and predicted undiscovered deposits. For legal reasons, the U.S. Geological Survey cannot update and maintain CES. Instead, statistical tools are under development to estimate mining costs from basic properties of mineral deposits such as tonnage, grade, mineralogy, depth, strip ratio, distance from infrastructure, rock strength, and work index. The first step was to reestimate "Taylor's Rule" which relates operating rate to available ore tonnage. The second step was to estimate statistical models of capital and operating costs for open pit porphyry copper mines with flotation concentrators. For a sample of 27 proposed porphyry copper projects, capital costs can be estimated from three variables: mineral processing rate, strip ratio, and distance from nearest railroad before mine construction began. Of all the variables tested, operating costs were found to be significantly correlated only with strip ratio.

The application of PGNAA borehole logging for copper grade estimation at Chuquicamata mine.

PubMed

Charbucinski, J; Duran, O; Freraut, R; Heresi, N; Pineyro, I

2004-05-01

The field trials of a prompt gamma neutron activation (PGNAA) spectrometric logging method and instrumentation (SIROLOG) for copper grade estimation in production holes of a porphyry type copper ore mine, Chuquicamata in Chile, are described. Examples of data analysis, calibration procedures and copper grade profiles are provided. The field tests have proved the suitability of the PGNAA logging system for in situ quality control of copper ore.

Rhenium, Molybdenum, Tungsten - Prospects for Production and Industrial Applications

DTIC Science & Technology

1998-06-18

concentrates from unique complex copper -containing porphyry deposit of the Almalyk region. The ore containing over 10 associated valuable constituents is...L.I.Ruzin, M .F.Sherem etyev ............................................... 71 Recovery of rhenium as by-product of treatment of molybdenite and copper ...for processing copper -molybdenum ores from "Erdenet- Ovoo" deposit S.Davaanyam, I.Sh.Sataev, Zh.Baatarkhuu, A.M.Desyatov, M.I.Khersonsky

Three Sub-Saharan Minerals: US Interests and Responses.

DTIC Science & Technology

1983-03-01

Minnesota, 50 million ounces; Montana, 225 32 million ounces; and others (including copper porphyries ), 5 million ounces. Recycling. Although platinum and...domestic mines and resources are low-grade 18 ores of less than 35 percent metal content. Arizona , Arkansas, Colorado, Maine and Minnesota have...these manganese deposits also contain nickel, copper and cobalt. Because of the prohibitive research and initial operating costs, plus the risk of

Genesis of the Bangbule Pb-Zn-Cu polymetallic deposit in Tibet, western China: Evidence from zircon U-Pb geochronology and S-Pb isotopes

NASA Astrophysics Data System (ADS)

Kan, Tian; Zheng, Youye; Gao, Shunbao

2016-04-01

The Banbule Pb-Zn-Cu skarn deposit is located in the Longger-Gongbujiangda volcanic magma arc in the Gangdese-Nyainqentanglha Plate. It is the only lead-zinc polymetallic deposit discovered in the westernmost Nyainqentanglha metallogenic belt. The measured and indicated resources include 0.9 Mt of Pb+Zn (4.77% Pb and 4.74% Zn, respectively), 6499 t of Cu, and 178 t of Ag (18.75g/t Ag). The orebodies mainly occur as lenses, veins and irregular shapes in the contact zone between the quartz-porphyry and limestone of the Upper Permian Xiala Formation, or in the boundaries between limestone and sandstone. Pb-Zn-Cu mineralization in the Banbule deposit is closely associated with skarns. The ore minerals are dominated by galena, sphalerite, chalcopyrite, bornite, and magnetite, with subordinate pyrite, malachite, and azurite. The gangue minerals are mainly garnet, actinolite, diopside, quartz, and calcite. The ore-related quartz-porphyry displays LA-ICP-MS zircon U-Pb age of 77.31±0.74 Ma. The δ34S values of sulfides define a narrow range of -0.8 to 4.7‰ indicating a magmatic source for the ore-forming materials. Lead isotopic systematics yield 206Pb/204Pb of 18.698 to 18.752, 207Pb/204Pb of 15.696 to 15.760, and 208Pb/204Pb of 39.097 to 39.320. The data points are constrained around the growth curves of upper crust and orogenic belt according to the tectonic discrimination diagrams. The calculated Δβ - Δγ values plot within the magmatic field according to the discrimination diagram of Zhu et al. (1995). The S-Pb isotopic data suggest that Bangbule is a typical skarn deposit, and the Pb-Zn-Cu mineralization is genetically related to the quartz-porphyry in the mining district. The discovery of the Bangbule deposit indicates that there is metallogenic potential in the westernmost Nyainqentanglha belt, which is of great importance for the exploration work in this area.

Sulphur-Rich Melt At Upper Crustal Levels At Cerro La Torta, Central Andes: Evidence From Melt Inclusions Assemblages.

NASA Astrophysics Data System (ADS)

Cannatelli, C.; Godoy, B.; Alvear, B.; Moncada, D.

2016-12-01

Central Andes present some of the biggest and most important porphyry copper ore deposits in the world. Porphyry copper ore formation is related to precipitation of ore minerals from sulphur and chlorine-rich fluids. Genesis of these deposits occurred 4 km below surface, while mineralized fluids are released by magmatic melts located between 5 and 15 km depth (Sillitoe, 2010). Cerro La Torta is part of a cluster of <105 ka rhyodacitic domes related to the waning stage of the Altiplano-Puna Volcanic Complex at Central Andes (Tierney et al., 2016). These domes reflect a crystal-rich mush layer at the upper crust - named Altiplano-Puna Magma Body (APMB) - which is proposed to be a voluminous partially molten body locate at shallow depth (4-25 km), with a thickness up to 11 km (Ward et al., 2014). Cerro La Torta is a crystal-rich ( 40% vol.) dacitic flow with plagioclase, amphibole, biotite, and quartz phenocrysts on a glassy (up to 50% vol.) groundmass. During detailed petrographic observation, two types of Melt Inclusions Assemblages (MIAs) were observed in the plagioclase. Group I is found in the core of crystals, and contains sulphide, pyrite ± bubbles. Group II of bubble-bearing MIAs is observed at the rim of the phenocrysts, with no associated sulphide mineral present. Melt Inclusions size ranges from 10-40 µm, suggesting an intermediate cooling rate (Roedder 1979). Out hypothesis is that during cooling, Group I MIA is trapped as result of a metal sulfur-rich event, leading to the suggestion that sulphide-bearing MIAs from Cerro La Torta are the evidence of mineralized magmas ponding at shallow crustal levels. Furthermore, the presence of MIAs in the mush-type magmas related to the APMB implies that such systems are suitable to porphyry copper ore generation. Roedder, 1979. The Evolution of the Igneous Rocks. 15-57 Sillitoe, 2010. Econ. Geol. 105:3-41 Tierney et al., 2016. Geology 44:683-686. doi:10.1130/G37968.1Ward et al., 2014. Earth Planet Sci Letters 404:43-54

Fluid evolution in a volcanic-hosted epithermal carbonate-base metal-gold vein system: Alto de la Blenda, Farallón Negro, Argentina

NASA Astrophysics Data System (ADS)

Márquez-Zavalía, M. Florencia; Heinrich, Christoph A.

2016-10-01

Alto de la Blenda is a ˜6.6-Ma intermediate-sulphidation epithermal vein system in the Farallón Negro Volcanic Complex, which also hosts the 7.1-Ma porphyry-Cu-Au deposit of Bajo de la Alumbrera. The epithermal vein system is characterised by a large extent and continuity (2 km × 400 m open to depth × 6 m maximum width) and an average gold grade of ˜8 g/t. The vein is best developed within an intrusion of a fine-grained equigranular monzonite, interpreted as the central conduit of a stratovolcano whose extrusive activity ended prior to porphyry-Cu-Au emplacement at Bajo de la Alumbrera, which is in turn cut by minor epithermal veins. The Alto de la Blenda vein consists predominantly of variably Mn-rich carbonates and quartz, with a few percent of pyrite, sphalerite, galena and other sulphide and sulphosalt minerals. Four phases of vein opening, hydrothermal mineralisation and repeated brecciation can be correlated between different vein segments. Stages 2 and 3 contain the greatest fraction of sulphide and gold. They are separated by the emplacement of a polymictic breccia containing clasts of quartz feldspar porphyry as well as basement rocks. Fluid inclusions in quartz related to stages 2 to 4 are liquid rich with 2-4 wt% NaCl(eq). They homogenise between 160 and 300 °C, with very consistent values within each assemblage. Vapour inclusions are practically absent in the epithermal vein. Quartz fragments in the polymictic breccia contain inclusions of intermediate to vapour-like density and similar low salinity (˜3 wt% NaCl(eq)), besides rare brine inclusions containing halite. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of epithermal inclusions indicate high concentrations of K, Fe, As, Sb, Cs, and Pb that significantly vary within and through subsequent vein stages. Careful consideration of detection limits for individual inclusions shows high gold concentrations of ˜0.5 to 3 ppm dissolved in the ore fluid, which

Solid Waste Composition Study at Taman Universiti, Parit Raja, Batu Pahat

NASA Astrophysics Data System (ADS)

Kadir, A. A.; Sani, M. S. A. M.

2016-07-01

Solid waste management is recognised as one of the most challenging issues confronted by both the developed and developing countries. The problems rise due to growing population in current years which results in increased generation of waste with various compositions. The aim of this study was to determine the waste compositions at Taman Universiti. Taman Universiti is a mix residential and commercial area which a preferred residential location amongst students and lecturers due to its proximate location to UTHM main campus. The waste collection was carried out for 50 houses on a daily basis. The collection and sorting out method was conducted according to Malaysian Standard MS 2505:2012 and the data was collected and recorded The result showed that the average generation rate of household waste at Taman Universiti was 0.16kg/person/day and the moisture content was approximately ranging from 61%-68%. Household wastes collected were categorized and it consisted of food and organic, paper, rigid plastics, plastics film, baby diapers, glass, tetra pak, household hazardous waste, metal, rubber, textiles, garden waste and leather. The proportion of each wastes were approximately 64.67%, 9.36%, 9.22%, 5.33%, 3.51%, 2.53%, 1.37%, 1.05%, 0.84%, 0.85%, 0.80%, 0.27%, and 0.23%, respectively. Results from the analyses indicated that the food and organic waste are the major composition of household waste at Taman Universiti followed by the paper, rigid plastics, and plastic film. Meanwhile, the proportion of baby diapers, glass, tetra pak, household hazardous waste, metal, rubber, textiles, and garden decreasing accordingly. In addition, leather was recognized as the least category that contributed to the household waste.

Instructional Model of Natural Science in Junior High Schools, Batu-Malang

ERIC Educational Resources Information Center

Pantiwati, Yuni; Wahyuni, Sri; Permana, Fendy Hardian

2017-01-01

The instruction of Natural Science subject in junior high schools, as regulated by 2013 Curriculum, is to be taught in an integrated way, combining Biology, Physics, and Chemistry subjects. The assessment of which is called authentic assessment. This current study described the instructional system especially the assessment system of Natural…

Neponset River Basin Massachusetts, Flood Plain Management Study.

DTIC Science & Technology

1982-03-01

extensive water power. There are in the southern village, two rolling mills, for the manufacture of copper bolts and sheathing, on a large scale; two...furnaces for refining copper , and casting bells and brass cannon (operated by Paul Revere): forges and furnaces for the manufacture of iron wheels and...Dedha Granodiorite, Westwood Granite, Sharon Syenite, and Blue Rills Granite Porphyry . Crushed Stone. The Mattapan Volcanic Complex and Westwood

Factors Affecting the Supply of Strategic Raw Materials with Particular Reference to the Aerospace Manufacturing Industry

DTIC Science & Technology

1984-04-01

element, recovered from the working of many porphyry copper deposits. As copper capacity i» now far beyond requirements, molybdenum should not be in...Source» Cobalt is mostly recovered aa a by-product of copper and nickel mining but world production is highly localised. Total annual production is...aluminium alloy containing lithium, copper and magnesium is under test. Por corrosion resistance there can be an Interchange with niobium. However

New Technologies to Reclaim Arid Lands User’s Manual

DTIC Science & Technology

2002-10-01

Dean, K. C., R. Havens, and K. T. Harper. 1969. Chemical and Vegetative Stabilization of a Nevada Copper Porphyry Mill Tailing. RI 7261. U.S. Dept...Hutchinson from the University of Arizona’s Office of Arid Land Studies, Tucson, Arizona ; Dr. Kathryn Thomas with the University ofNorthern Arizona ...Flagstaff, Arizona ; Dr. Von Winkel formerly with Science Applications International (now with the Las Vegas Valley Water District); Dr. Steven Monsen

Utilization of Seismic and Infrasound Signals for Characterizing Mining Explosions

DTIC Science & Technology

2001-10-01

different types of mining operations exist, ranging from surface coal cast blasting to hard rock fragmentation blasting in porphyry copper mines. The study...both seismic and infrasound signals. The seismic coupling of large-scale cast blasts in Wyoming, copper fragmentation blasts in Arizona and New Mexico...mining explosions from the copper fragmentation blasts in SE Arizona were observed at Los Alamos. Detected events were among the largest of the blasts

Resource Management Technology: Los Alamos Technical Capabilities for Emergency Management,

DTIC Science & Technology

1983-07-18

synthetic fuels from coal (analogous to the Fischer-Tropsch process), olefin polymerization, and flue - gas desulfurization . In order to successfully...world. It has been a major research effort here for decades. Also, in the area of desulfurization of flue gases, Los Alamos scientists have been...Tectonic and Geochemical Controls on Copper-Molybdenum Porphyry Mineralization in the Southwestern United States (M. J. Aldrich and A. W. Laughlin) 1.0.6

Geology and mineral resources of the Port Moller region, western Alaska Peninsula, Aleutian arc: A section in USGS research on mineral resources - 1989: Program and abstracts

USGS Publications Warehouse

Wilson, Frederic H.; White, Willis H.; Detterman, Robert L.

1988-01-01

Geologic mapping of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles was begun under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP) in 1983 . Two important mineral deposits are located in the Port Moller quadrangle; the Pyramid prospect is the largest copper porphyry system in the Aleutian Arc, and the Apollo Mine is the only gold mine to reach production status in the Aleutian Arc.

Mineral resources of the Elkhorn Wilderness Study Area, Broadwater and Jefferson Counties, Montana

USGS Publications Warehouse

Greenwood, William R.; Ludington, Steve; Miller, William R.; Hanna, William F.; Wenrich, Karen J.; Suits, Vivian J.; McHugh, John B.

1990-01-01

The Elkhorn Wilderness Study Area in west-central Montana has a moderate to high potential for resources of porphyry-type copper and molybdenum in the western part of the area, and a moderate to high potential for resources of gold, silver, lead, and zinc in replacement and vein deposits in the eastern part of the area. No evidence of potential oil, gas, and geothermal resources was identified in this study.

Computer finds ore

NASA Astrophysics Data System (ADS)

Bell, Peter M.

Artificial intelligence techniques are being used for the first time to evaluate geophysical, geochemical, and geologic data and theory in order to locate ore deposits. After several years of development, an intelligent computer code has been formulated and applied to the Mount Tolman area in Washington state. In a project funded by the United States Geological Survey and the National Science Foundation a set of computer programs, under the general title Prospector, was used successfully to locate a previously unknown ore-grade porphyry molybdenum deposit in the vicinity of Mount Tolman (Science, Sept. 3, 1982).The general area of the deposit had been known to contain exposures of porphyry mineralization. Between 1964 and 1978, exploration surveys had been run by the Bear Creek Mining Company, and later exploration was done in the area by the Amax Corporation. Some of the geophysical data and geochemical and other prospecting surveys were incorporated into the programs, and mine exploration specialists contributed to a set of rules for Prospector. The rules were encoded as ‘inference networks’ to form the ‘expert system’ on which the artificial intelligence codes were based. The molybdenum ore deposit discovered by the test is large, located subsurface, and has an areal extent of more than 18 km2.

Low-fluorine Stockwork Molybdenite Deposits

USGS Publications Warehouse

Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

2009-01-01

Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

Selenium content in sulfide ores from the Chalkidiki peninsula, Greece.

PubMed

Nicolaidou, A E

1998-01-01

Selenium (Se) was assessed in galena, sphalerite, and pyrite samples. These are components of mixed sulfide ores from the Olympias and Madem Lakkos-Mavres Petres deposits and the Skouries porphyry-copper deposit. We used atomic absorption spectroscopy (AAS) with a hydride generator system. The highest concentration of Se (516 ppm) was found in the fine-grained galena at the -135 level of the Olympias deposits. In the Madem Lakkos-Mavres Petres deposit, the highest concentration of Se (33 ppm) was found in the pyrites of the level 30. The concentration of Se in the arsenopyrites and chalcopyrites is lower than the detection limit of the analytical method (< 100 ppb). The concentrated chalcopyrite from the porphyry copper deposit at Skouries exhibits a significant Se content (average 200 ppm) in contrast to the chalcopyrite from the Olympias and the Madem Lakkos-Mavres Petres. Variations in the Se content of the sulfide minerals studied could be caused by redox-pH and/or temperature conditions, as well as by the difference in crystal structure. The Se found in the areas studied may positively affect the environment. Sulfide minerals are oxidized by microorganisms, infiltrate in the soil-water in the form of selenate or selenite ion, and directly or indirectly influence the human organism.

Evidence for extreme partitioning of copper into a magmatic vapor phase.

PubMed

Lowenstern, J B; Mahood, G A; Rivers, M L; Sutton, S R

1991-06-07

The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits.

China Report, Economic Affairs, No. 397

DTIC Science & Technology

1983-11-10

porphyry copper have also been discovered, together with molybdenum, tungsten, gold, silver and iron. Tibet’s potential reserve of copper is...abroad aimed at using optical fibres instead of copper and aluminum wires for the relaying of information. According to statistics, the energy required...to produce this kind of fibre is only one-thousandth of the energy required to mine, smelt, and process the same length of copper wire. After the

Proceedings, Seminar on Probabilistic Methods in Geotechnical Engineering Held at Vicksburg, Mississippi on 21 September 1982.

DTIC Science & Technology

1983-09-01

al. (1981) was conducted on Copper City No. 2 tailings embankment damn near Miami, Arizona . Due to the extreme topographic relief in the area of the...mode of behavior and scale. ThiL dependency is summarized in the factor R. For example, circular shear instability as in a copper porphyry slope...OF THE PROBABILISTIC SLOPE STABILITY MODEL. . 32 6.1 DESCRIPTION OF COPPER CITY NUMBER 2 TAILINGS DAM . . 32 6.2 SUBSURFACE INVESTIGATION

Ground Based Free Electron Laser Technology Integration Experiment, White Sands Missile Range, New Mexico

DTIC Science & Technology

1987-01-01

The volcanic intrusive mass, known as the Cerro Colorado, is Eocene to early Miocene age, and has scattered peaks of basaltic porphyries that rise a...Orogrande site. Mining activities in this district produced primarily gold, silver, copper , lead, iron and turquoise. Production in this district peaked in...volumes. 17. U.S. Fish and Wildlife Service. 1984. Endangered species of Arizona and New Mexico. Region 2. Albuquerque, New Mexico. 18. U.S. Fish and

Cultural Resources Intensive Survey and Testing of Mississippi River Levee Berms, Crittenden and Desha Counties, Arkansas and Mississippi, Scott, Cape Girardeau and Pemiscot Counties, Missouri Item R-618 Knowlton; Desha County, Arkansas.

DTIC Science & Technology

1983-11-01

grave goods such as copper beads, pipes, raw, rare materials, and conch shells from the Gulf are common (Haag 1971:18). The Hopewellilan concept of...WILMSEN, E. N. 1970 Lithic Analysis and Cultural Inference: A Paleo-Indian Case. Anthropological Papers of the University of Arizona 16. 1973...ground celt of black porphyry (Figure C-3:d). It shows some chipping along one longitudinal side. This tool is 10 centimeters in length, 3.5 centimeters

The Ajo Mining District, Pima County, Arizona--Evidence for Middle Cenozoic Detachment Faulting, Plutonism, Volcanism, and Hydrothermal Alteration

USGS Publications Warehouse

Cox, Dennis P.; Force, Eric R.; Wilkinson, William H.; More, Syver W.; Rivera, John S.; Wooden, Joseph L.

2006-01-01

Introduction: The Ajo porphyry copper deposit and surrounding Upper Cretaceous rocks have been separated from their plutonic source and rotated by detachment faulting. Overlying middle Cenozoic sedimentary and volcanic rocks have been tilted and show evidence for two periods of rotation. Following these rotations, a granitic stock (23.7?0.2 Ma) intruded basement rocks west of the Ajo deposit. This stock was uplifted 2.5 km to expose deep-seated Na-Ca alteration.

A deposit model for Mississippi Valley-Type lead-zinc ores: Chapter A in Mineral deposit models for resource assessment

USGS Publications Warehouse

Leach, David L.; Taylor, Ryan D.; Fey, David L.; Diehl, Sharon F.; Saltus, Richard W.

2010-01-01

This report also describes the geoenvironmental characteristic of MVT deposits. The response of MVT ores in the supergene environment is buffered by their placement in carbonate host rocks which commonly results in near-neutral associated drainage water. The geoenvironmental features and anthropogenic mining effects presented in this report illustrates this important environmental aspect of MVT deposits which separates them from other deposit types (especially coal, VHMS, Cu-porphyry, SEDEX, acid-sulfate polymetallic vein).

The partitioning behavior of silver in a vapor brine rhyolite melt assemblage

NASA Astrophysics Data System (ADS)

Simon, Adam C.; Pettke, Thomas; Candela, Philip A.; Piccoli, Philip M.

2008-03-01

The partitioning of silver in a sulfur-free rhyolite melt-vapor-brine assemblage has been quantified at 800 °C, pressures of 100 and 140 MPa and f≈NNO (nickel-nickel oxide). Silver solubility (±2 σ) in rhyolite increases 5-fold from 105 ± 21 to 675 ± 98 μg/g as pressure increases from 100 to 140 MPa. Nernst-type partition coefficients (DAgi,j±2σ) describing the mass transfer of silver at 100 MPa between vapor and melt, brine and melt and vapor and brine are 32 ± 30, 1151 ± 238 and 0.026 ± 0.004, respectively. At 140 MPa, values for DAgi,j(±2σ) for vapor and melt, brine and melt, and vapor and brine are 32 ± 10, 413 ± 172 and 0.06 ± 0.03, respectively. Apparent equilibrium constant values (±2 σ) describing the exchange of silver and sodium between vapor and melt, KAg,Nav/m, at 100 and 140 MPa are 105 ± 68 and 14 ± 6. The average values (±2 σ) for silver and sodium exchange between brine and melt, KAg,Nab/m, at 100 and 140 MPa are 313 ± 288 and 65 ± 12. These data indicate that the mass transfer of silver from rhyolite melt to an exsolved volatile phase(s) is enhanced at 100 MPa relative to 140 MPa, suggesting that decompression increases the silver ore-generative potential of an evolving silicate magma. Model calculations using the new data suggest that the evolution of low-density, aqueous fluid (i.e., vapor) may be responsible for the the silver tonnage of many porphyry-type and perhaps epithermal-type ore deposits. For example, Halter et al. (Halter W. E., Pettke T. and Heinrich C. A. (2002) The origin of Cu/Au ratios in porphyry-type ore deposits. Science296, 1842-1844) used detailed silicate and sulfide melt inclusion and vapor and brine fluid inclusions analyses to estimate a melt volume on the order of 15 km 3 to satisfy the copper budget at the Bajo de la Alumbrera copper-, gold-, silver-ore deposit. Using their melt volume estimate with the data presented here, model calculations for a 15-km 3 felsic melt, saturated with pyrrhotite

Bus driving assistance system for town area by using ATmega328P microcontroller

NASA Astrophysics Data System (ADS)

Zakaria, Mohamad Fauzi; Soon, Tan Jiah; Rohani, Munzilah Md

2017-09-01

Recently, several bus accidents happened because of bus driver's behavior. In fact, there is no dedicated tool for assisting them to drive safely. This project gives solutions to this by assisting the driver, according to the speed and acceleration of the bus. These data are collected by using a motion processing unit (MPU-6050) and a global positioning system (GPS) and then indicate the driving mode status on the LEDs. All data and status are recorded in a secure digital (SD) card for the authority or the bus company to analyze the driving behavior of a bus driver. This system has been successfully developed and tested in two different areas which includes the UTHM main campus and the road from Parit Raja to Batu Pahat.

GEOLOGY, SULFUR ISOTOPES AND THE ORIGIN OF THE HEATH STEELE ORE DEPOSITS, NEWCASTLE, N.B., CANADA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dechow, E.

The Heath Steele mine is located 35 miles northwest of Newcastle, New Brunswick, Canada. Middle Ordovician Tetagouche Group rocks, consisting of siliceous and basic volcanic rocks, and fine-grained quartz sericite schists and porphyry, have been folded into a steeply plunging recumbent anticline. The ore deposits of zinc, lead, and copper are associated with minor folding and/or sheared dilatent zones at or near the contact between porphyry and fine-grained senicitic schist. Mineralogically the sulfide bodies consist of early, euhedral arsenopyrite, magnetite, and pyrite, followed by interstitial pyrrhotite, sphalerite, chalcopyrite and galena. Minor minerals are ternantite-tetrahedrite, bismuthinite, marcasite, hematite, and some graphite.more » Supergene minerals consist of chalcocite, covellite, and marcasite with a little native silver. Little hypogene replacement has taken place between the minerals, which show a "porphyritic" texture. Sulfur isotope ratios were determined for over 150 sulfide and sulfate specimens from five of the seven ore bodies, and from granite, acid and basic volcanics, porphyry, and sediments. The results indicate that there is no detectable fractionation either during hypogene mineralization or supergene enrichment. The spread (21.82 to 22.02) covered by the ratios is narrow, and suggestive of a well homogenized source of mineral solutions. The enrichment of S/sup 34/ in the ore sulfides and the presence of graphite, evident from mineralographic studies and mass spectrometric analysis, suggests reduction of original sulfates (known to be enriched in S/sup 34/) by organic carbon at temperatures in excess of 500 deg C. A calculation based on the isotopic exchange reaction between sulfide and sulfate under equilibrium conditions and the spread of the ratios indicates a temperature of 700 to 800 deg C for the source. Finally the ratios determined for sulfides in a gneissic granite close to Heath Steele have the same ratio as the ore

A geochemical study of the Sweet Home Mine, Colorado Mineral Belt, USA: hydrothermal fluid evolution above a hypothesized granite cupola

NASA Astrophysics Data System (ADS)

Lüders, Volker; Romer, Rolf L.; Gilg, H. Albert; Bodnar, Robert J.; Pettke, Thomas; Misantoni, Dean

2009-05-01

Deposition of quartz-molybdenite-pyrite-topaz-muscovite-fluorite and subsequent hübnerite and sulfide-fluorite-rhodochrosite mineralization at the Sweet Home Mine occurred coeval with the final stage of magmatic activity and ore formation at the nearby world-class Climax molybdenum deposit about 26 to 25 m.y. ago. The mineralization occurred at depths of about 3,000 m and is related to at least two major fluid systems: (1) one dominated by magmatic fluids, and (2) another dominated by meteoric water. The sulfur isotopic composition of pyrite, strontium isotopes and REY distribution in fluorite suggest that the early-stage quartz-molybdenite-pyrite-topaz-muscovite-fluorite mineral assemblage was deposited from magmatic fluids under a fluctuating pressure regime at temperatures of about 400°C as indicated by CO2-bearing, moderately saline (7.5-12.5 wt.% NaCl equiv.) fluid inclusions. LA-ICPMS analyses of fluid inclusions in quartz demonstrate that fluids from the Sweet Home Mine are enriched in incompatible elements but have considerably lower metal contents than those reported from porphyry-Cu-Au-Mo or Climax-type deposits. The ore-forming fluid exsolved from a highly differentiated magma possibly related to the deep-seated Alma Batholith or distal porphyry stock(s). Sulfide mineralization, marking the periphery of Climax-type porphyry systems, with fluorite and rhodochrosite as gangue minerals was deposited under a hydrostatic pressure regime from low-salinity ± CO2-bearing fluids with low metal content at temperatures below 400°C. The sulfide mineralization is characterized by mostly negative δ34S values for sphalerite, galena, chalcopyrite, and tetrahedrite, highly variable δ18O values for rhodochrosite, and low REE contents in fluorite. The Pb isotopic composition of galena as well as the highly variable 87Sr/86Sr ratios of fluorite, rhodochrosite, and apatite indicates that at least part of the Pb and Sr originated from a much more radiogenic source than

Voluminous and crystal-rich igneous rocks of the Permian Wurzen volcanic system, northern Saxony, Germany: physical volcanology and geochemical characterization

NASA Astrophysics Data System (ADS)

Repstock, Alexander; Breitkreuz, Christoph; Lapp, Manuel; Schulz, Bernhard

2018-06-01

The North Saxon Volcanic Complex (NSVC) is a nested caldera edifice dominated by the c. 295 Ma Rochlitz Volcanic System and the c. 289 Ma Wurzen Volcanic System (WVS). The climactic activity of the WVS resembled a VEI ≥ 7 fissure `supereruption' resulting in voluminous and crystal-rich caldera-fill ignimbrites (minimum volume c. 199 km3); caldera outflow facies is not known sofar. Precursory to the WVS `monotonous intermediates', rhyolitic and rhyodacitic volcanic activity led to deposition of the low-volume Wermsdorf and Cannewitz ignimbrites. Modal analysis of the WVS pyroclastic units reveals an inhomogeneous crystal population (≤ 58 vol%) comprising k-feldspar, plagioclase, quartz, ortho- and clinopyroxene and minor amounts of biotite. The Wurzen caldera fill ignimbrites feature three types of fiamme: (1) felsic fiamme; (2) mafic fiamme; and (3) granite-porphyry fiamme. This, the modal variation, and the common presence of clinopyroxene and biotite indicate a strong magma mingling component in the WVS—characteristics which have not been observed in the precursory, Wermsdorf and Cannewitz ignimbrites. The caldera fill ignimbrites feature a large compositional variation from (basaltic) trachyandesite to rhyolite caused by basaltic injection and magma mingling. It is proposed that magmatic underplating led to reheating crystal mush and finally to convection processes within the WVS magma chamber. The predominance of either pyroxene or biotite as mafic mineral in the (trachy-) dacitic to rhyolitic ignimbrites indicates eruption of crystal mush from different magma batches. Prominent negative Nb and Ta anomalies of the Wurzen caldera fill ignimbrites, porphyries, and mafic dykes indicate enhanced melt-crust interaction or contamination of mantle melt. In the aftermath of the WVS caldera eruption, basaltic, trachyandesitic, andesitic and rhyolitic melts ascended puncturing the Wurzen-α and β ignimbrites leading to an array of NW-SE-trending dykes, subvolcanic

Reconnaissance geology of the Precambrian rocks in the Ayn Qunay quadrangle, Kingdom of Saudi Arabia

USGS Publications Warehouse

Overstreet, William C.; Whitlow, Jesse William; Ankary, Abdullah O.

1972-01-01

The Aya Qunay quadrangle covers an area of 2833 sq km in central Saudi Arabia, Only the western edge of the quadrangle is underlain by Precambrian rocks, which were the subject of this investigation. Toward the east the Precambrian rocks are unconformably overlain by Permian and younger sedimentary rocks. The Permian rocks at the west edge of the Ayn Qunay quadrangle consist mainly of a granitic intrusive complex of batholithic dimensions. Parts of the eastern edge of the granitic complex are exposed just west of the overlying Khuff Formation of Permian age, where biotite-hornblende granite of the complex intrudes chlorite-sericite schist of the Precambrian Bi'r Khountina Group. The biotite-hornblende granite of the complex also intrudes plutons of diorite, gabbro, and pyroxenite and is itself intruded by granite porphyry, thereby indicating some difference in age between the granitic rocks in the complex. A sequence of metamorphosed volcanic rocks composed mainly of andesite, rhyolite, and kindred rocks, and called the Halaban Group, is older than the Bi'r Khountina Group. Relations between the Halaban and a gray hornblende-biotite granite gneiss are uncertain, but the gneiss may be older than the Halaban. The few observed contacts disclosed parallel foliation in the two units, but the foliation may have been imposed after the Halaban was deposited on the granite gneiss. Two major left-lateral faults extend west-northwest across the Precambrian rocks but are not in the Permian rocks. These faults parallel to the Najd fault zone found farther south. Seemingly they correlate in time with early movements on the Najd fault zone, but not with the latest. Saprolitic material-of variable thickness is present on the upper surface of the Precambrian rocks beneath the Khuff Formation at many places. Where the Khuff Formation has been removed by erosion, the saprolite is also stripped away. The weathering probably took place in pre-Khuff time. No ancient mines or prospects

Numerical Modeling of Multiphase Fluid Flow in Ore-Forming Hydrothermal Systems

NASA Astrophysics Data System (ADS)

Weis, P.; Driesner, T.; Coumou, D.; Heinrich, C. A.

2007-12-01

Two coexisting fluid phases - a variably saline liquid and a vapor phase - are ubiquitous in ore-forming and other hydrothermal systems. Understanding the dynamics of phase separation and the distinct physical and chemical evolution of the two fluids probably plays a key role in generating different ore deposit types, e.g. porphyry type, high and low sulfidation Cu-Mo-Au deposits. To this end, processes within hydrothermal systems have been studied with a refined numerical model describing fluid flow in transient porous media (CSP~5.0). The model is formulated on a mass, energy and momentum conserving finite-element-finite-volume (FEFV) scheme and is capable of simulating multiphase flow of NaCl-H20 fluids. Fluid properties are computed from an improved equation of state (SOWAT~2.0). It covers conditions with temperatures of up to 1000 degrees~C, pressures of up to 500 MPa, and fluid salinities of 0~to 100%~NaCl. In particular, the new set-up allows for a more accurate description of fluid phase separation during boiling of hydrothermal fluids into a vapor and a brine phase. The geometric flexibility of the FEFV-meshes allows for investigations of a large variety of geological settings, ranging from ore-forming processes in magmatic hydrothermal system to the dynamics of black smokers at mid-ocean ridges. Simulations demonstrated that hydrothermal convection patterns above cooling plutons are primarily controlled by the system-scale permeability structure. In porphyry systems, high fluid pressures develop in a stock rising from the magma chamber which can lead to rock failure and, eventually, an increase in permeability due to hydrofracturing. Comparisons of the thermal evolution as inferred from modeling studies with data from fluid inclusion studies of the Pb-Zn deposits of Madan, Bulgaria are in a strikingly good agreement. This indicates that cross-comparisons of field observations, analytical data and numerical simulations will become a powerful tool towards a

Geochronological framework of the early Paleozoic Bainaimiao Cu-Mo-Au deposit, NE China, and its tectonic implications

NASA Astrophysics Data System (ADS)

Zhou, Zhen-Hua; Mao, Jing-Wen; Ma, Xing-Hua; Che, He-Wei; Ou'yang, He-Gen; Gao, Xu

2017-08-01

The Bainaimiao Cu-Mo-Au deposit of NE China is an important ore deposit in the middle section of the northern margin of the North China Craton. The early Paleozoic Bainaimiao Group is the main ore-hosting rock. The mineralization at the deposit shows features of porphyry alteration and late-stage orogenesis and transformation. Zircon LA-ICP-MS U-Pb age data indicate that the ages of the Third and Fifth formations of the Bainaimiao Group are 492.7 ± 2.9 Ma (MSWD = 0.53) and 488.9 ± 3.1 Ma (MSWD = 0.92), respectively. The age of quartz diorite that intrudes the Bainaimiao Group is 459.3 ± 6.4 Ma (MSWD = 2.20). Molybdenite samples from massive Cu-Mo-bearing ores and quartz veins in the southern ore belt yield a Re-Os isochron age of 438.2 ± 2.7 Ma (MSWD = 0.16), which is consistent with the Re-Os isochron age of molybdenite in the northern ore belt, implying that the two ore belts belong to the same mineralization system. Muscovite from a post-magmatic Cu-Mo-bearing quartz-calcite vein yields an Ar-Ar isochron age of 422.5 ± 3.9 Ma (MSWD = 0.64) with an initial 40Ar/36Ar ratio of 286 ± 21. The well-defined plateau age of the muscovite is 422.4 ± 2.6 Ma (MSWD = 0.05), which represents the time of the post-magmatic orogenic transformation event. Based on our new age data and previous findings, we propose that the Bainaimiao Cu-Mo-Au deposit formed in an active continental margin setting and experienced four stages of ore mineralization: (1) a Late Cambrian-Middle Ordovician volcanic-sedimentary stage; (2) a Late Ordovician porphyry mineralization stage; (3) a Late Silurian regional metamorphism stage; and (4) an orogenic transformation stage. Subhedral and euhedral Paleoproterozoic (2402-1810 Ma) inherited zircons indicate that the Bainaimiao Group has a tectonic affinity with the North China Craton. The Central Asian Orogenic Belt, which is closely related to the complex closure of the Paleo-Asian Ocean, is favorable for prospecting for Paleozoic porphyry Cu

Tellurium, a guide to mineral deposits

USGS Publications Warehouse

Watterson, J.R.; Gott, G.B.; Neuerburg, G.J.; Lakin, H.W.; Cathrall, J.B.

1977-01-01

Te dispersion patterns are useful in exploring for different types of mineral deposits and in providing additional information about known ore deposits. The Te content of rocks is given for five mining districts in the western United States: Coeur d'Alene, Idaho; Robinson, near Ely, Nevada; Montezuma, Colorado; Crater Creek area, Colorado; Cripple Creek, Colorado. Many of the analyses were obtained by use of a new analytical method sensitive to 0.001 ppm Te. The principal ore deposits in the Coeur d'Alene district, Idaho, are Pb-Zn-Ag replacement veins in Precambrian rocks of the Belt Supergroup. Te dispersion patterns show the outlines of the original mineral belts, the effects of intrusive events, the location of ore deposits, the displacements caused by post-ore faulting, and the borders of the 780-km2 district. The disseminated porphyry Cu deposits of the Robinson mining district, Nevada, are associated with Cretaceous quartz monzonite stocks that have intruded Palaeozoic carbonate rocks. Te is present in rock samples in concentrations as high as 10,000 ppm and forms a halo around the areas containing the Cu deposits. The alteration zones in the porphyry Mo district near Montezuma, Colorado, are developed around several small Tertiary intrusions occurring along a regional shear zone. Te haloes reflect the locations of porphyry intrusives, individual deposits and their ore shoots, and the pattern and intensity of adjacent alteration. The Te content of soils over the Montezuma stock is higher than, and varies independently from, the Te content of adjacent outcrops. Soils generally contain more Te than adjacent outcropping rocks. Soil may collect gaseous Te compounds from mineral deposits. The Crater Creek area is a northwestern extension of the Summitville mining district, Colorado. Te dispersion patterns radiate out from exposed Cu-Pb-Zn veins, from an outcrop of molybdenite stockwork veins and from associated iron-stained altered rock. Te haloes intensify

Geologic setting and characteristic of mineral deposits in the central Wasatch Mountains, Utah

USGS Publications Warehouse

John, David A.

1997-01-01

Base- and precious-metal deposits in the central Wasatch Mountains southeast of Salt Lake City were mined for more than 100 years beginning in 1868. Deposits present in the Park City, Little Cottonwood, and Big Cottonwood mining districts include Ag-Pb-Zn ± Cu ± Au replacement and veins, a low-grade porphyry Cu-Au deposit, Cu-bearing skarns, a quartz monzonite-type (low F) porphyry Mo deposit, and high sulfidation (quartz-alunite) Au deposits. Most production came from polymetallic replacement and vein deposits in the Park City mining district, which has a recorded production of more than 1.4 million oz Au , 253 million oz Ag, 2.7 billion lbs Pb, 1.5 billion lbs Zn, and 129 million lbs Cu from 1872 to 1978. Production in the Little and Big Cottonwood districts, mostly from Pb-Ag replacement deposits, was much smaller. Most mineral deposits in the central Wasatch Mountains are genetically related to the Wasatch igneous belt, a series of high-K calc-alkaline stocks and cogenetic volcanic rocks that formed about 41(?) to 30 Ma. The mineral deposits mostly formed near the end of magmatic activity between about 36 to 31.4 Ma. A subeconomic porphyry Mo deposit in the Little Cottonwood stock is notably younger having formed about 26 to 23.5 Ma. The intrusive rocks were emplaced mostly along the westward extension of the west-trending Uinta arch during a period of NW-SE-directed extension, and much of the mineralization in the Park City district controlled by ENE-striking normal faults. About 15 degrees of eastward tilting of the central Wasatch Mountains during Late Cenozoic Basin and Range extension has resulted in progressively deeper levels of exposure from <1 km on the east to about 11 km on the west and in profound variations in the types of minerals deposits exposed in different parts of the range. Most deposits formed at paleodepths ≤5 km, and the most productive deposits in the Park City district formed at depths of 1 to 2 km. The prophyry Mo deposit in the

Identification and Description of Geophysical Techniques.

DTIC Science & Technology

1980-11-01

electrodes are used for voltage measurements with the potentiometer. Current elec- trodes may be stainless-steel or copper rods, buried copper screens, drill...steel in a borehole, or buried metal culverts. Potential elec- trodes may be stainless steel rods or porous containers filled with copper sulfate...Granite 28-2,700 Diorite 47 Gabbro 68-2,370 Porphyry 47 Diabase 78-1,050 Basalt 680 Olivine-Diabase 2,000 1. Peridotite 12,500 I (1)Adapted from C. A

Mineral Deposits and Mineral Potential of the Randsburg Wash Test Range.

DTIC Science & Technology

1983-12-01

prescreen samples to determine poten- tial worth by looking for lead, zinc, iron, silver K-alpha and K-beta excitation peaks, and arsenic and copper ...workings. The descrip- tion of the layout of the mining claims taken from the notice places 4G. Montague Butler. "Some Facts About Ore Deposits." Arizona ...intrusive is a porphyry with a white groundmass and quartz phenocrysts up to I millimeter across. Phenocrysts make up less than 10% of the rock. The

Solid Waste Composition and Quantification at Taman Melewar, Parit Raja, Batu Pahat

NASA Astrophysics Data System (ADS)

Kadir, A. A.; Abidin, S. S. S. Z.

2016-07-01

The poor management of solid waste is noticeable through the increasing of the solid waste each year and the difficulties in disposing the waste in the current available landfill. This study was undertaken to analyze the quantity and composition of waste generation in Taman melewar. Taman Melewar is a student residential area and this study is focusing on student's daily waste composition. The objective of this study was to identify the amount of solid waste generation, analyze and classify the composition of solid waste in Taman Melewar. The waste collection was conducted for 50 houses on a daily basis for two weeks. The average household waste generation rate was 0.082 kg/person/day. Organic waste was the major constituent of waste production. The average of organic waste represents about 72.4% followed by paper (9%), plastics film (5.5%), plastics rigid (4.7%), napkins (3.8%), tetrapek (1.3%), glass (1.1%), household hazardous waste (0.85%), textiles (0.52%), metal (0.51%) and rubber (0.34%). The moisture content was ranging from 27.67% to 28.68%. An evaluation was made based on student's behavior towards waste production and recycling. In conclusion, the results revealed that organic waste is the highest waste generated and recycling habits is also poor in Taman Melewar.

Identification of geostructures of continental crust, particularly as they relate to mineral-resource evaluation

NASA Technical Reports Server (NTRS)

Gryc, G. (Principal Investigator); Lathram, E. H.

1972-01-01

The authors have identified the following significant results. As a precursor to the ERTS-1 investigation, the spatial relationship of geostructures seen on Nimbus IDCS photographs to the distribution of mineralized areas in Alaska and western Canada was analyzed to determine the possible metallogenic significance of the geostructures. In Canada, mercury and porphyry molybdenum deposits are closely associated with strong northwest-trending fault systems; the development of mineralized regions seems related to major crustal zones or fractures trending southwestward across the Cordillera from the Precambrian shield. In Alaska, comparison of the northeast- and northwest-trending set of possible crustal structures shown on the Nimbus photo, with the distribution of known mineral deposits suggests a similar relationship. The mineralized region of massive sulfides in Prince William Sound and upper Copper River areas and of porphyry coppers in the Nabesna area forms a broad northeast-trending belt possibly related to the Minto Arch on the Shield. The belt of metalliferous deposits in the western Alaska Range follows a comparable northeast trend. Mercury deposits, suggested by many to be fault-controlled, together with most tin and tungsten deposits, occupy a northeast-trending belt between the Bristol Bay-Mackenzie Bay linear and extensions of a linear along the lower Yukon River. This belt intersects the northwest-trending Canadian belt of similar deposits in the Fairbanks area.

The Coast Artillery Journal. Volume 77, Number 6, November-December 1934

DTIC Science & Technology

1934-12-01

The Tsingtau peninsula, between Lau schan and Kiautschou Bays, is a rocky headland of granite and porphyry , but to the north of the Pai scha ho the...has un- dergone a rather complete overhaul since its first water trials, receiving a coat of anti-fouling paint, a copper ex- haust pipe and a bronze...and rate it as excellent. No filters or chlorinators are used. Every 48 hours five pounds of copper sulphate are placed in a perforated can in front

Patterns of reflected radiance associated with geobotanical anomalies

NASA Technical Reports Server (NTRS)

Birnie, R. W.; Stone, T. A.; Francica, J. R.

1985-01-01

This paper summarizes three remote sensing experiments in which changes in remotely measured reflected radiance patterns of vegetation correlated with changes in geology. In two cases using airborne spectroradiometer data, changes in the physical properties of a uniform species correlated with zones of porphyry copper mineralization. In another case using Landsat digital data, changes were detected in the distribution and density of a number of species and combined with soil brightness data to produce a composite index useful for distinguishing lithologies.

Molecular and Electronic Structure of Thin Films of Protoporphyrin(IX)Fe(III)C1

DTIC Science & Technology

1991-11-10

Union Carbide). Electrical contact to the back side of the HOPG sample was made with a copper wire and conductive epoxy (Epo-tek H20E, Epoxy Technology...analysis of the contrast in STM images of copper phthalocyanine [641 and by Zheng and Tsong in their analysis of resonant tunneling via tip-localized...Electroanal. Chem. 1980, 110, 369. 71. Makinen, M.W.; Churg A.K. Iron Porphyri ns-P art One; Lever, A.B.P.; Gray, H.B., Eds.; Physical Bioinorganic

Structural Engineering. Loads. Design Manual 2.2.

DTIC Science & Technology

1981-11-01

cast, rolled 534 Locust 46 Bronze, 7.9 to 14% Sn 509 Maple, hard 43 Bronze, aluminum 481 Maple, white 33 Copper , cast, rolled 556 Oak, chestnut 54... Copper ore, pyrites 262 Oak, live 59 Gold, cast, hammered 1205 Oak, red, black 41 Gold, bars, stacked 1133 Oak, white 46 Gold, coin in bags 1084 Pine...Phosphate rock, apatite 200 Glass, crystal 184 Porphyry 172 Hay and straw - bales 20 Pumice, natural 40 Leather 59 Quartz, flint 165 Paper 58 Sandstone

The importance of protected areas for the forest and endemic avifauna of Sulawesi (Indonesia).

PubMed

Lee, Tien Ming; Sodhi, Navjot S; Prawiradilaga, Dewi M

2007-09-01

Protected areas are critical for the conservation of residual tropical forest biodiversity, yet many of these are being deforested by humans both within and outside of their administrative boundaries. Therefore, it is critical to document the significance of protected areas for conserving tropical biodiversity, particularly in mega-diverse Southeast Asia. We evaluated the importance of protected areas (national parks [NP], nature reserves [NR], and wildlife reserves [WR]) in preserving avifaunal diversity, particularly the endemic and forest species, on the island of Sulawesi. This island has one of the highest numbers of endemic avifauna genera (12) globally and is also experiencing heavy deforestation. Rarefaction analyses and species estimators showed that parks and reserves consistently recorded higher number of forest, endemic, and endemic forest bird species, in addition to larger population densities, than in their surrounding human-modified areas across eight protected areas (Gunung Manembo-nembo WR, Tangkoko-Batu Angus and Dua Saudara NR, Gunung Ambang NR, Bogani Nani Wartabone NP, Gunung Tinombala NR, Gunung Sojol NR, Lore Lindu NP, and Rawa Aopa Watumohai NP). This implies that protecting natural forests must remain as one of the fundamental conservation strategies in Sulawesi. Two small reserves (Gunung Manembo-nembo WR and Tangkoko-Batu Angus and Dua Saudara NR), however, had high number of forest and endemic bird species both within and outside their boundaries, suggesting the importance of buffer areas for augmenting small reserves so as to improve their conservation value. Ordination analyses revealed the differential response of bird species to different environmental factors (e.g., native tree cover), highlighting the significance of forested habitats with dense native vegetation cover for effective conservation of forest dependent and endemic avifauna. In addition, the distinctiveness in bird species composition among protected areas highlights

Petrology, geochemistry and U-Pb geochronology of magmatic rocks from the high-sulfidation epithermal Au-Cu Chelopech deposit, Srednogorie zone, Bulgaria

NASA Astrophysics Data System (ADS)

Chambefort, Isabelle; Moritz, Robert; von Quadt, Albrecht

2007-10-01

Chelopech area and the about 92-Ma-old Elatsite porphyry-Cu deposit, suggest two different magma sources in the Chelopech-Elatsite magmatic area. Magmatic rocks associated with the Elatsite porphyry-Cu deposit and the dacitic dome-like body north of Chelopech are characterized by zircons with ɛHfT90 values of ˜5, which suggest an important input of mantle-derived magma. Some zircons display lower ɛHfT90 values, as low as -6, and correlate with increasing 206Pb/238U ages up to about 350 Ma, suggesting assimilation of basement rocks during magmatism. In contrast, zircon grains in andesitic rocks from Chelopech are characterized by homogeneous 176Hf/177Hf isotope ratios with ɛHfT90 values of ˜1 and suggest a homogeneous mixed crust-mantle magma source. We conclude that the Elatsite porphyry-Cu and the Chelopech high-sulfidation epithermal deposits were formed within a very short time span and could be partly contemporaneous. However, they are related to two distinct upper crustal magmatic reservoirs, and they cannot be considered as a genetically paired porphyry-Cu and high-sulfidation epithermal related to a single magmatic-hydrothermal system centered on the same intrusion.

The metal content of molybdenum-mineralizing fluids

NASA Astrophysics Data System (ADS)

Lerchbaumer, L.; Audétat, A.

2012-04-01

Molybdenum can be found in porphyry-type systems as well as in hydrothermal veins and breccias associated with granite systems. Up to now our knowledge on the metal content of fluids forming molybdenum ore deposits has been very limited. The only data available so far are from the porphyry Mo deposit at Questa, New Mexico, and from the Cave Peak porphyry Mo-Nb deposit in Texas. We have studied early, intermediate-density fluid inclusions in quartz crystals from miarolitic cavities in the Drammen and Glitrevann granites (Norway) and the Treasure Mountain Dome (Colorado/USA) to obtain more information about the bulk composition of magmatic-hydrothermal fluids exsolved from these plutons. The Treasure Mountain Dome contains weak Mo mineralization and is an apophysis of the Alma Batholith that produced also the famous Climax and Henderson porphyry Mo deposits; the Glitrevann granite hosts a sub-economic Mo stockwork, and the Drammen Granite contains numerous vein-type Mo mineralizations. As a preliminary result, based on analyses of fluid inclusions using optical microscopy, microthermometry, Raman spectroscopy, and LA-ICP-MS we conclude that the primordial fluid of the Drammen granite was of high acidity and carried certain amounts of metals at conditions of 650°C and 1.3-1.5 kbar. The total elemental budget is: 3 wt% Na, 1.8 wt% K, 0.5 wt% S, 0.4 wt% Fe, 0.3 wt% Cu, 0.2 wt% Mn, 40 ppm Mo, 800 ppm Zn, 600 ppm Rb, 300 ppm Cs, 180 ppm Pb, 150 ppm As, 40 ppm W, 15 ppm Bi, and minor amounts of Ag, Sn, and Ce. Striking is the fact, that all the metal concentrations show little variability except the one of Cu. In view of recent studies (Lerchbaumer & Audétat, 2011) showing that the Cu-values in quartz-hosted fluid inclusions are not always representative of the primary fluid and in fact can be too high, we want to check if this could be the case for the Cu-values measured in the samples from Norway and Colorado. The alteration of the original Cu-concentrations stems from

Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, Clark County, Nevada

USGS Publications Warehouse

Vikre, Peter G.; Browne, Quentin J.; Fleck, Robert J.; Hofstra, Albert H.; Wooden, Joseph L.

2011-01-01

in ore breccias and relatively low S and Pb isotope values (δ34S values vary from 0–~4‰; 206Pb/204Pb <18.5). Copper ± precious metal-PGE deposits (Cu, Co, Ag, Au, Pd, and Pt) consist of Cu carbonate minerals (after chalcocite and chalcopyrite) and fine-grained quartz that have replaced breccia clasts and margins of fissures in Paleozoic limestones and dolomites near porphyritic intrusions. Gold ± silver deposits occur along contacts and within small-volume stocks and dikes of feldspar porphyry, one textural variety of porphyritic intrusions. Lead isotope compositions of copper ± precious metal-PGE, gold ± silver, and lead-dominant carbonate replacement deposits are similar to those of Mojave crust plutons, indicating derivation of Pb from 1.7 Ga crystalline basement or from Late Proterozoic siliciclastic sedimentary rocks derived from 1.7 Ga crystalline basement.Four texturally and modally distinctive porphyritic intrusions are exposed largely in the central part of the district: feldspar quartz porphyry, plagioclase quartz porphyry, feldspar biotite quartz porphyry, and feldspar porphyry. Intrusions consist of 64 to 70 percent SiO2 and variable K2O/Na2O (0.14–5.33) that reflect proportions of K-feldspar and albite phenocrysts and megacrysts as well as partial alteration to K-mica; quartz and biotite phenocrysts are present in several subtypes. Albite may have formed during emplacement of magma in brine-saturated basinal strata, whereas hydrothermal alteration of matrix, phenocrystic, and megacrystic feldspar and biotite to K-mica, pyrite, and other hydrothermal minerals occurred during and after intrusion emplacement. Small volumes of garnet-diopside-quartz and retrograde epidote-mica-amphibole skarn have replaced carbonate rocks adjacent to one intrusion subtype (feldspar-quartz porphyry), but alteration of carbonate rocks at intrusion contacts elsewhere is inconspicuous.Uranium-lead ages of igneous zircons vary inconsistently from ~ 180 to 230 Ma and

The physical hydrology of magmatic-hydrothermal systems: High-resolution 18O records of magmatic-meteoric water interaction from the Yankee Lode tin deposit (Mole Granite, Australia)

NASA Astrophysics Data System (ADS)

Fekete, Szandra; Weis, Philipp; Driesner, Thomas; Heinrich, Christoph A.; Baumgartner, Lukas; Bouvier, Anne-Sophie

2016-04-01

apparent discrepancy can be explained by the presence of a fluid of meteoric origin that was isotopically equilibrated with a hot, but already solidified and fractured granitic intrusion under rock-dominated conditions prior their transfer to the cold ore deposition site (Heinrich, 1990). Conversely, in porphyry copper systems meteoric fluid incursion has been assumed to participate in formation of peripheral or post-mineralization processes (Bowman et al., 1987; Sillitoe, 2010; Williams-Jones and Migdisov, 2014). However, recent numerical simulations of porphyry copper systems identify a significant role of meteoric fluids for the enrichment process, providing a cooling mechanism for metal-rich fluids expelled from an upper crustal magma chamber (Weis et al. 2012, Weis 2015). Furthermore, new petrographic and fluid inclusion work of ore-mineralized quartz veins (Landtwing et al., 2010; Stefanova et al., 2014) indicates lower (˜ 450r{ }C) than magmatic fluid temperatures for copper precipitation. Given that the Yankee Lode study validated the capability of high resolution, in situ δ 18O analysis to trace meteoric water incursion, we will apply this method to hydrothermal quartz samples from two significant porphyry copper deposits (Bingham Canyon, USA and Elatsite, Bulgaria). By this we intend to better constrain a potential role of meteoric water incursion in porphyry copper ore precipitation. REFERENCES Audétat, A., Günther, D., Heinrich, C. A. 1998: Formation of a Magmatic-Hydrothermal Ore Deposit: Insights with LA-ICP-MS Analysis of Fluid Inclusions: Science, 279, 2091-2094. Audétat, A. 1999: The magmatic-hydrothermal evolution of the Sn/W-mineralized Mole Granite (Eastern Australia): PhD Thesis, 211. Bowman, J. R., Parry, W. T., Kropp, W. P., and Kruer, S. A., 1987: Chemical and isotopic evolution of hydrothermal solutions at Bingham, Utah: Economic Geology, 82, 395-428. Heinrich, C.A. 1990: The Chemistry of Hydrothermal Tin(-Tungsten) Ore Deposition: Economic

Coper Isotope Fractionation in Porphyry Copper Deposits: A Controlled Experiment

NASA Astrophysics Data System (ADS)

Ruiz, J.; Mathur, R.; Uhrie, J. L.; Hiskey, B.

2001-12-01

Previous studies have shown that copper is fractionated in the environment. However, the mechanisms for isotope fractionation and the role of organic and inorganic processes in the fractionation are not well understood. Here we used the well controlled experiments used by Phelps Dodge Corporation aimed at leaching copper from their ore deposits to constrain the mechanism of copper isotope fractionation in natural systems. The isotope data were collected on a Micromass Isoprobe. High temperature copper sulfides from ore deposits in Chile and Arizona yield delta 65Cu near 0 permil. The reproducibility of the data is better that 0.1 permil. Controlled experiments consisting of large columns of rocks were fed solutions containing bacteria such as Thiobacillus ferroxidans and Leptospirrilium ferroxidan. Solutions fom the columns were sampled for sixty days and analyzed for copper concentrations, oxidation potential, ferrous/ferric ratios and pH. The results indicate that the bacterially aided dissolution of copper fractionated copper. Preliminary experiments of copper dissolution not using bacteria show no isotope fractionation The original rock in the experiment has a delta 65Cu of -2.1. The first solutions that were collected from the columns had a delta 65Cu of -5.0 per mil. The liquid changed its isotopic composition from -50 to -10 during the sixty days of sampling. The greatest shift in the isotope ratios occurred the first 30 days when the copper recovered was less than 40% and the ferrous/ferric ratios were somewhat constant. At approximately 35 days after the start of the experiments, the copper recovery increases the ferrousferric ratio decreased and the copper isotope ratio of the fluids remained fairly constant. The data suggest that the bacteria are required to effectively fractionate copper isotopes in natural systems and that the mechanisms of bacterial aided copper dissolution may include a direct dissolution of the sulfides by the bacteria. Experiments underway with enzimes without the bacteria may confirm this hypothesis. The data obtained in these experiments will provide some constraints in the use of copper isotopes as proxy for life in the rock record.

MX Siting Investigation. Mineral Resources Survey, Seven Additional Valleys, Nevada/Utah Siting Area. Volume II.

DTIC Science & Technology

1981-06-23

Minerals Inc. Box 90 W. Grace #100 Reno NV 89509 Anaconda Copper Co. 555 17th Street Denver CO 80217 Argus Resources Inc. Box 56 Austin NV 93099 Armenian...Donald F. 7272 Lindale Drive Sacramento CA 95828 Combined Metals Red. 1865 S. Main St. Salt Lake City UT 84115 Conlan, Mary Helen N/A Copper Range Co...hApl. Co. Mineral Services co. N/A Miragliotta, Vito 1184 S. 1000 E. Clearfield UT 84015 Neeser, Earl Francis Box 495 Goldfield NV 89013 Nev. Porphyry

Self-ordering and complexity in epizonal mineral deposits

USGS Publications Warehouse

Henley, Richard W.; Berger, Byron R.

2000-01-01

Giant deposits are relatively rare and develop where efficient metal deposition is spatially focused by repetitive brittle failure in active fault arrays. Some brief case histories are provided for epithermal, replacement, and porphyry mineralization. These highlight how rock competency contrasts and feedback between processes, rather than any single component of a hydrothermal system, govern the size of individual deposits. In turn, the recognition of the probabilistic nature of mineralization provides a firmer foundation through which exploration investment and risk management decisions can be made.

Petrogenesis of Ore-Bearing and Ore-Barren Intermediate-Acid Intrusive Rocks from Jilongshan Au-Cu Skarn Deposit , the Middle-Lower Yangtze River Metallogenic Belt, Eastern China and their Geological Implications

NASA Astrophysics Data System (ADS)

Zhan, X.; Wei, J.; Chen, M.; Zhao, X.

2017-12-01

Jilongshan Au-Cu skarn deposit in Edong-Jiurui ore district , Middle-Lower Yangtze River Metallogenic Belt(MLYRB) , eastern China ,contains 44 t gold and 32 Mt of copper ores. The mineralization is dominated by massive skarn ores, most of which occurs along the contact zone between the lower Triassic dolomitic limestones and Jilongshan granodioritic intrusion. However, Baiguoshu pluton, no more than 1 km western, has been not found any mineralized occurrence with the same strata. The ore-bearing and ore-barren intrusive rocks are granodiorite porphyries, could not be identified by petrographic characters. Besides, Zircon U-Pb dating results demonstrate that Jilongshan and Baiguoshu intrusion emplaced at 140 ± 1Ma and 141 ± 1 Ma respectively, coeval with the Early Cretaceous magmatism in Edong-Jiurui area. Elements geochemistry present that they are both characterized by high Al2O3, rich Na2O (Na2O/K2O>1.0), enrichment of LILE (Rb, Ba, K, Sr) and depletion of HFSE (Nb, Ta), and weak negative Eu anomalies, which suggest they may be originated from partial melting of enriched mantle and associated with crust-mantle interaction ,evidenced by the Sr-Nd-Hf isotopic composition as well. Although the two are partly geochemically similar with each other, they have some obvious differences. The former have higher K2O and Y, Yb ,lower MgO, and Cr, Ni contents, and more obvious differentiation degree between light and heavy REEs with (La/Yb)N=10.55-15.95 than the latter with (La/Yb)N=8.67-10.47. It is indicated that the magmas of the Jilongshan intrusive rocks were probably derived from deeper source than that of the Baiguoshu, also supported by mineralogical data of biotite. In addition, Jilongshan intrusive rocks have a relatively higher initial Nd (ɛNd (t) = -8.2 - -9.4) and Sr ((87Sr/86Sr)i=0.70822-0.70897) isotopic composition than Baiguoshu (-9.2 - -9.7 and 0.70855-0.70881), as same as Lu-Hf isotopic composition. Therefore, combined with previous studies, we suggest

Solubility of gold in oxidized, sulfur-bearing fluids at 500-850 °C and 200-230 MPa: A synthetic fluid inclusion study

NASA Astrophysics Data System (ADS)

Guo, Haihao; Audétat, Andreas; Dolejš, David

2018-02-01

Although Au solubility in magmatic-hydrothermal fluids has been investigated by numerous previous studies, there is a dearth of data on oxidized (log fO2 > FMQ+2.5; FMQ - fayalite-magnetite-quartz buffer), sulfur-bearing fluids such as those that formed porphyry Cu-Au (-Mo) deposits. We performed experiments to constrain the effects of fluid salinity, HCl content, sulfur content, fO2 and temperature on Au solubility in such oxidized, sulfur-bearing fluids. For this purpose, small aliquots of fluids equilibrated with Au metal were trapped at high pressure and temperature in the form of synthetic fluid inclusions in quartz and were subsequently analyzed by LA-ICP-MS. Additionally, Raman spectra were collected from quartz-hosted fluid inclusions at up to 600 °C to help to identify the nature of dissolved gold and sulfur species. Gold solubility was found to be affected most strongly by the HCl content of the fluid, followed by fO2, fluid salinity and temperature. Compared to these factors the sulfur content of the fluid has relatively little influence. At 600 °C and 100 MPa, fluids with geologically realistic HCl contents (∼1.1 wt%) and salinities (7-50 wt% NaClequiv) dissolve ∼1000-3000 ppm Au at oxygen fugacities controlled by the magnetite-hematite buffer. At even more oxidized conditions (three log units above the hematite-magnetite fO2 buffer), HCl-, NaCl- and H2SO4-rich fluids can dissolve up to 5 wt% Au at 800 °C and 200 MPa. The observed Au solubility trends are controlled by HCl0 species in the Na-H-Cl-SO4 fluid and are quantitatively reproduced by existing thermodynamic data for Au-Cl complexes. In all experiments, AuCl0 and AuCl2- species are predicted to occur in comparable although variable concentrations, and account for more than 95% of Au solutes. Natural, high-temperature (>500 °C) brine inclusions from porphyry Cu-Au (-Mo) deposits contain significantly less Au than gold-saturated brines that were synthesized experimentally, implying that the

Early paleozoic granodioritic plutons in the Shedong W-Mo ore district, Guangxi, southern China: Products of re-melting of middle Proterozoic crust due to magma underplating

NASA Astrophysics Data System (ADS)

Jiang, Xingzhou; Kang, Zhiqiang; Xu, Jifeng; Feng, Zuohai; Pang, Chongjin; Fang, Guicong; Wu, Jiachang; Xiong, Songquan

2017-06-01

The Shedong W-Mo ore district in the south-central Dayaoshan Uplift of Guangxi, southern China hosts the Baoshan and Pingtoubei deposits, both of which occur in granodioritic plutons. Zircon U-Pb dating of granodiorites and its mafic microgranular enclaves (MMEs) in the Baoshan deposit yielded ages of 439.8 ± 3.2 and 441.1 ± 2.2 Ma, respectively. Granodiorites have moderate SiO2 (54.5-63.0 wt.%) and high Al2O3 (15.4-17.8 wt.%) contents, wide variations in major element ratios, significant rare earth element fractionation, and small negative Eu anomalies. They are rich in Th, U, Zr, and Hf, and depleted in Ba, Nb, and Ti. Their initial 87Sr/86Sr, εNd(t), and εHf(t) values are in the range of 0.7086-0.7091, -5.2 to -6.6 and -6.3 to +1.6, respectively. Rounded or lenticular MMEs have relatively low silica and high mafic components, depletion in Eu, Sr, and Zr, and marked negative Eu anomalies. Rb/Sr and Nb/Ta ratios, and εNd(t) and εHf(t) values of the MMEs are higher than those of host granodiorites, indicating a different magmatic source. Zircon U-Pb dating of the unexposed granodiorite porphyry in the Pingtoubei deposit yielded an age of 440.0 ± 1.7 Ma. The granodiorite porphyries have high SiO2 and low K2O, FeOT, and MgO contents, with similar trace element features to the granodiorites at the Baoshan deposit, although the former has small negative Eu anomalies. Its initial 87Sr/86Sr values range from 0.7162 to 0.7173, εNd(t) values from -8.7 to -12.3, and εHf(t) values from -7.8 to +1.3, indicative of a crustal source. Nd and Hf two-stage model ages of the granodiorites, MMEs, and granodiorite porphyries have a narrow range between 1.3 and 2.2 Ga. We propose that the granodiorites and MMEs at the Baoshan deposit were produced through re-melting of middle Proterozoic crust as a result of underplating of mantle-derived magmas in a transitional compression-to-extension tectonic setting. Mantle-derived magmas provided the heat and material for the formation

The tectonic evolution of the Irtysh tectonic belt: New zircon U-Pb ages of arc-related and collisional granitoids in the Kalaxiangar tectonic belt, NW China

NASA Astrophysics Data System (ADS)

Hong, Tao; Klemd, Reiner; Gao, Jun; Xiang, Peng; Xu, Xing-Wang; You, Jun; Wang, Xin-Shui; Wu, Chu; Li, Hao; Ke, Qiang

2017-02-01

Precise geochronological constraints of the Irtysh tectonic belt situated between the Saur Island Arc and the Altay Terrane are crucial to a better understanding of the tectonic evolution of the Central Asian Orogenic Belt (CAOB). Recently, we discovered repeatedly deformed arc-related and collisional granitoids in the Kalaxiangar tectonic belt (KTB), which is located in the eastern part of the Irtysh tectonic belt. In this study, we report new whole-rock geochemical, zircon U-Pb and Hf isotopic data of the arc-related and collisional granitoids. Our data reveal that 1) arc-related granodioritic porphyries formed at ca. 382-374 Ma. Recrystallized zircon grains from a (ultra-)mylonitic granodiorite of the Laoshankou zone in the southern KTB display a U-Pb age of ca. 360 Ma; 2) syn-collisional granodioritic porphyries, which distribute along faults and parallel to the cleavage, were emplaced at ca. 367-356 Ma, with εHf(t) values varying from + 7.8 to + 14.2 and Hf model ages from 873 to 459 Ma; 3) a post-collisional A-type granodioritic porphyry, which crosscuts the NW-NNW trending schistosity of the metasedimentary country rocks at a low angle, has an age of ca. 324-320 Ma, while the εHf(t) values range from + 7.6 to + 14.4 with Hf model ages from 850 to 416 Ma; 4) post-collisional strike-slip A-type granite dykes, exposed along strike-slip faults, gave ages between 287 and 279 Ma, whereas the εHf(t) values range from + 4.9 to + 12.7 and the Hf model ages from 995 to 500 Ma; and 5) A-type biotite granite dykes, which intruded along conjugate tension joints, have ages of 274-271 Ma, and εHf(t) values from + 1.5 to + 13.2 with Hf model ages from 1196 to 454 Ma. Consequently, we propose that the collision between the Saur Island Arc and the Altay Terrane occurred in the Early Carboniferous (ca. 367-356 Ma) and the subsequent post-collisional tectonic process continued to the Late Carboniferous (ca. 324-320 Ma). It is further suggested that the Irtysh tectonic belt

Dominant risk factors for malaria at Puskesmas Labuhan Ruku, Talawi Batu Bara, Indonesia

NASA Astrophysics Data System (ADS)

Eyanoer, P. C.

2018-03-01

Malaria is a disease which increases in number almost every year. Morbidity rate of malaria tends to decline from 4.1 to 0.85 per 1000 population at risk in 2005 to 2015. In North Sumatera alone three areas found with the highest incidences are District of Madina, Batubara, and Asahan. However such high number do not parallel with the utilization of health services in the area.This study is an analytic study withcase-controldesign to analyses the contribution of environmental and social factors that potentially cause malaria among people living in malaria-endemic areas. The recruited samples are 146 samples. All cases are registered patient at Puskesmas Labuhan Ruku while controls are from the neighboring area. The result showed that incidence of malaria is most affected by the habit of repellent used and being outside of the house in the evening.

Drinking Water Quality of Water Vending Machines in Parit Raja, Batu Pahat, Johor

NASA Astrophysics Data System (ADS)

Hashim, N. H.; Yusop, H. M.

2016-07-01

An increased in demand from the consumer due to their perceptions on tap water quality is identified as one of the major factor on why they are mentally prepared to pay for the price of the better quality drinking water. The thought that filtered water quality including that are commercially available in the market such as mineral and bottled drinking water and from the drinking water vending machine makes they highly confident on the level of hygiene, safety and the mineral content of this type of drinking water. This study was investigated the vended water quality from the drinking water vending machine in eight locations in Parit Raja are in terms of pH, total dissolve solids (TDS), turbidity, mineral content (chromium, arsenic, cadmium, lead and nickel), total organic carbon (TOC), pH, total colony-forming units (CFU) and total coliform. All experiments were conducted in one month duration in triplicate samples for each sampling event. The results indicated the TDS and all heavy metals in eight vended water machines in Parit Raja area were found to be below the Food Act 1983, Regulation 360C (Standard for Packaged Drinking Water and Vended water, 2012) and Malaysian Drinking Water Quality, Ministry of Health 1983. No coliform was presence in any of the vended water samples. pH was found to be slightly excess the limit provided while turbidity was found to be 45 to 95 times more higher than 0.1 NTU as required by the Malaysian Food Act Regulation. The data obtained in this study would suggest the important of routine maintenance and inspection of vended water provider in order to maintain a good quality, hygienic and safety level of vended water.

Geochemical evidence for a brooks range mineral belt, Alaska

USGS Publications Warehouse

Marsh, S.P.; Cathrall, J.B.

1981-01-01

Geochemical studies in the central Brooks Range, Alaska, delineate a regional, structurally controlled mineral belt in east-west-trending metamorphic rocks and adjacent metasedimentary rocks. The mineral belt extends eastward from the Ambler River quadrangle to the Chandalar and Philip Smith quadrangles, Alaska, from 147?? to 156??W. longitude, a distance of more than 375 km, and spans a width from 67?? to 69??N. latitude, a distance of more than 222 km. Within this belt are several occurrences of copper and molybdenum mineralization associated with meta-igneous, metasedimentary, and metavolcanic rocks; the geochemical study delineates target areas for additional occurrences. A total of 4677 stream-sediment and 2286 panned-concentrate samples were collected in the central Brooks Range, Alaska, from 1975 to 1979. The -80 mesh ( 2.86) nonmagnetic fraction of the panned concentrates from stream sediment were analyzed by semiquantitative spectrographic methods. Two geochemical suites were recognized in this investigation; a base-metal suite of copper-lead-zinc and a molybdenum suite of molybdenum-tin-tungsten. These suites suggest several types of mineralization within the metamorphic belt. Anomalies in molybdenum with associated Cu and W suggest a potential porphyry molybdenum system associated with meta-igneous rocks. This regional study indicates that areas of metaigneous rocks in the central metamorphic belt are target areas for potential mineralized porphyry systems and that areas of metavolcanic rocks are target areas for potential massive sulfide mineralization. ?? 1981.

The Chahnaly low sulfidation epithermal gold deposit, western Makran volcanic arc, southeastern Iran

USGS Publications Warehouse

Sholeh, Ali; Rastad, Ebrahim; Huston, David L.; Gemmell, J. Bruce; Taylor, Ryan D.

2016-01-01

The Chahnaly Au deposit formed during the early stages of magmatism. LA-ICP-MS zircon U-Pb geochronology of host andesite and 40Ar/39Ar dating of two samples of gold-associated adularia show that the ore-stage adularia (19.83 ± 0.10 and 19.2 ± 0.5 Ma) is younger, by as much as 1.5 million years, than the volcanic host rock (20.32 ± 0.4 Ma). Therefore, either hydrothermal activity continued well after volcanism or a second magmatic event rejuvenated hydrothermal activity. This second magmatic event may be related to eruption of porphyritic andesite at ~20.32 ± 0.40 Ma, which is within error of ~19.83 ± 0.10 Ma adularia. The new LA-ICP-MS zircon U-Pb host rock and vein adularia 40Ar/39Ar ages suggest that early Miocene magmatism and mineralization in the Bazman area is of a similar age to that of the Saindak porphyry and Tanjeel porphyry center of the giant Reko Diq deposit. This confirms the existence of early Miocene arc magmatism and mineralization along the Iranian part of the Makran volcanic arc. Ore, alteration mineralogy, and alteration patterns indicate that the Chahnaly deposit is a typical low-sulfidation epithermal Au deposit, located in a poorly explored part of the Makran volcanic arc in Iran.                   

A stable downward continuation of airborne magnetic data: A case study for mineral prospectivity mapping in Central Iran

NASA Astrophysics Data System (ADS)

Abedi, Maysam; Gholami, Ali; Norouzi, Gholam-Hossain

2013-03-01

Previous studies have shown that a well-known multi-criteria decision making (MCDM) technique called Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE II) to explore porphyry copper deposits can prioritize the ground-based exploratory evidential layers effectively. In this paper, the PROMETHEE II method is applied to airborne geophysical (potassium radiometry and magnetometry) data, geological layers (fault and host rock zones), and various extracted alteration layers from remote sensing images. The central Iranian volcanic-sedimentary belt is chosen for this study. A stable downward continuation method as an inverse problem in the Fourier domain using Tikhonov and edge-preserving regularizations is proposed to enhance magnetic data. Numerical analysis of synthetic models show that the reconstructed magnetic data at the ground surface exhibits significant enhancement compared to the airborne data. The reduced-to-pole (RTP) and the analytic signal filters are applied to the magnetic data to show better maps of the magnetic anomalies. Four remote sensing evidential layers including argillic, phyllic, propylitic and hydroxyl alterations are extracted from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images in order to map the altered areas associated with porphyry copper deposits. Principal component analysis (PCA) based on six Enhanced Thematic Mapper Plus (ETM+) images is implemented to map iron oxide layer. The final mineral prospectivity map based on desired geo-data set indicates adequately matching of high potential zones with previous working mines and copper deposits.

Kinetics of Electrocatalysis of Dibromoalkyl Reductions Using Electrodes with Covalently Immobilized Metallotetraphenylporphyrins.

DTIC Science & Technology

1981-01-29

Technical Report Using Electrodes with Covalently Immobilized Metal l otetraphenyl porphyri ns G. PERFORMING ORG. REPORT NUMBER 7. AU𔄁IOR(’.) 0...and CH2BrCHBrCH 3 at the surfaces of electrodes to which cobalt(II) or copper (II) tetra(p-aminophenyl)porphyrin has been covalently attached is strongly...27514 ABSTRACT The reduction of PhCHBrCH 2 Br, PhCHBrCHBrPh, and CH2BrCHBrCH3 at the surfaces of electrodes to which cobalt(lI) or copper (If) tetra(p

Field survey of the March 28, 2005 Nias-Simeulue earthquake and Tsunami

USGS Publications Warehouse

Borrero, J.C.; McAdoo, B.; Jaffe, B.; Dengler, L.; Gelfenbaum, G.; Higman, B.; Hidayat, R.; Moore, A.; Kongko, W.; ,; Peters, R.; Prasetya, G.; Titov, V.; Yulianto, E.

2011-01-01

On the evening of March 28, 2005 at 11:09 p.m. local time (16:09 UTC), a large earthquake occurred offshore of West Sumatra, Indonesia. With a moment magnitude (Mw) of 8.6, the event caused substantial shaking damage and land level changes between Simeulue Island in the north and the Batu Islands in the south. The earthquake also generated a tsunami, which was observed throughout the source region as well as on distant tide gauges. While the tsunami was not as extreme as the tsunami of December 26th, 2004, it did cause significant flooding and damage at some locations. The spatial and temporal proximity of the two events led to a unique set of observational data from the earthquake and tsunami as well as insights relevant to tsunami hazard planning and education efforts. ?? 2010 Springer Basel AG.

Nature, diversity of deposit types and metallogenic relations of South China

USGS Publications Warehouse

Zaw, K.; Peters, S.G.; Cromie, P.; Burrett, C.; Hou, Z.

2007-01-01

the 'Northern Golden Triangle' of China. These deposits are mostly epigenetic hydrothermal micron-disseminated gold deposits with associated As, Hg, Sb + Tl mineralisation similar to Carlin-type deposits in USA. The important deposits in the Southern Golden Triangle are Jinfeng (Lannigou), Zimudang, Getang, Yata and Banqi in Guizhou Province, and the Jinya and Gaolong deposits in Guangxi District. The most important deposits in the Northern Golden Triangle are the Dongbeizhai and Qiaoqiaoshang deposits. Many porphyry-related polymetallic copper-lead-zinc and gold skarn deposits occur in South China. These deposits are related to Indosinian (Triassic) and Yanshanian (Jurassic to Cretaceous) magmatism associated with collision of the South China and North China Cratons and westward subduction of the Palaeo-Pacific Plate. Most of these deposits are distributed along the Lower to Middle Yangtze River metallogenic belt. The most significant deposits are Tonglushan, Jilongshan, Fengshandong, Shitouzui and Jiguanzui. Au-(Ag-Mo)-rich porphyry-related Cu-Fe skarn deposits are also present (Chengmenshan and Wushan in Jiangxi Province and Xinqiao, Mashan-Tianmashan, Shizishan and Huangshilaoshan in Anhui Province). The South China fold belt extending from Fujian to Zhejiang Provinces is characterised by well-developed Yanshanian intrusive to subvolcanic rocks associated with porphyry to epithermal type mineralisation and mesothermal vein deposits. The largest porphyry copper deposit in China, Dexing, occurs in Jiangxi Province and is hosted by Yanshanian granodiorite. The high-sulphidation epithermal system occurs at the Zijinshan district in Fujian Province and epithermal to mesothermal vein-type deposits are also found in the Zhejiang Province (e.g., Zhilingtou). Part of Shandong Province is located at the northern margin of the South China Craton and the province has unique world class granite-hosted orogenic gold deposits. Occurrences of Pt-Pd-Ni-Cu-Co are found in Permian

Copper Diffusion in Silicate Melts and Melt Inclusion Study on Volatiles in The Lunar Interior

NASA Astrophysics Data System (ADS)

Ni, Peng

This thesis focuses on the application of diffusion kinetics to both terrestrial and lunar geochemistry. In Chapters II and III, diffusivities of Cu in silicate melts were experimentally determined and used to discuss the role of Cu diffusion in formation of Cu ore deposits and also Cu isotope fractionation in tektites. In Chapters IV and V, lunar olivine-hosted melt inclusions are studied to understand their volatile loss during homogenization in lab, to estimate cooling rate for lunar Apollo sample 74220, and to estimate volatile abundance in the lunar mantle. Magmatic sulfide deposits and porphyry-type Cu deposits are two major types of Cu deposits that supply the world's Cu. In particular, porphyry-type Cu deposits provide ˜57% of the world's total discovered Cu. Recent studies suggest a potential role of diffusive transport of metals (e.g. Cu, Au, PGE, Mo) in the formation of magmatic sulfide deposits and porphyry-type deposits. Diffusivities of Cu in silicate melts, however, are poorly determined. In Chapters II and III of this thesis, Cu diffusion in basaltic melt and rhyolitic melts are studied by diffusion couple and chalcocite "dissolution" methods. Our results indicate high diffusivities of Cu and a general equation for Cu diffusion in silicate melts is obtained. The high diffusivity of Cu indicate that partition of Cu between the silicate phase and the sulfide or fluid phase can be assumed to be in equilibrium during the formation of magmatic sulfide deposits or porphyry-type deposits. In addition, our Cu diffusion data helps explain why Cu isotopes are more fractionated than Zn isotopes in tektites. Volatile abundances in the lunar mantle have profound implications for the origin of the Moon, which was thought to be bone-dry till about a decade ago, when trace amounts of H2O were detected in various types of lunar samples. In particular, high H2O concentrations comparable to mid-ocean ridge basalts were reported in lunar melt inclusions. There are

The oxidation state, and sulfur and Cu contents of arc magmas: implications for metallogeny

NASA Astrophysics Data System (ADS)

Richards, Jeremy P.

2015-09-01

Global data for measured Fe2O3/FeO ratios and Cu contents in unaltered volcanic and intrusive arc rocks indicate that, on average, they are slightly more oxidized than other magmas derived from depleted upper mantle (such as MORB), but contain similar Cu contents across their compositional ranges. Although Cu scatters to elevated values in some intermediate composition samples, the bulk of the data show a steady but gentle trend to lower concentrations with differentiation, reaching modal values of 50-100 ppm in andesitic rocks. These data suggest that Cu is mildly compatible during partial melting and fractionation processes, likely reflecting minor degrees of sulfide saturation throughout the magmatic cycle. However, the volume of sulfides must be small such that significant proportions of the metal content remain in the magma during fractionation to intermediate compositions. Previous studies have shown that andesitic magmas containing 50 ppm Cu can readily form large porphyry-type Cu deposits upon emplacement in the upper crust. A review of the literature suggests that the elevated oxidation state in the asthenospheric mantle wedge source of arc magmas (ΔFMQ ≈ + 1 ± 1) derives from the subduction of seawater-altered and oxidized oceanic crust, and is transmitted into the mantle wedge via prograde metamorphic dehydration fluids carrying sulfate and other oxidizing components. Progressive hydration and oxidation of the mantle wedge may take up to 10 m.y. to reach a steady state from the onset of subduction, explaining the rarity of porphyry deposits in primitive island arcs, and the late formation of porphyries in continental arc magmatic cycles. Magmas generated from this metasomatized and moderately oxidized mantle source will be hydrous basalts containing high concentrations of sulfur, mainly dissolved as sulfate or sulfite. Some condensed sulfides (melt or minerals) may be present due to the high overall fS2, despite the moderately high oxidation state

Phanerozoic continental growth and gold metallogeny of Asia

USGS Publications Warehouse

Goldfarb, Richard J.; Taylor, Ryan D.; Collins, Gregory S.; Goryachev, Nicolay A.; Orlandini, Omero Felipe

2014-01-01

; and (8) Jurassic(?) ores on the margins of the Subumusu block in Myanmar and Malaysia. Circum-Pacific tectonism led to major orogenic gold province formation along the length of the eastern side of Asia between ca. 135 and 120 Ma, although such deposits are slightly older in South Korea and slightly younger in the Amur region of the Russian Southeast. Deformation related to collision of the Kolyma–Omolon microcontinent with the Pacific margin of the Siberia craton led to formation of 136–125 Ma ores of the Yana–Kolyma belt (Natalka, Sarylakh) and 125–119 Ma ores of the South Verkhoyansk synclinorium (Nezhdaninskoe). Giant ca. 125 Ma gold provinces developed in the Late Archean uplifted basement of the decratonized North China block, within its NE edge and into adjacent North Korea, in the Jiaodong Peninsula, and in the Qinling Mountains. The oldest gold-bearing magmatic–hydrothermal deposits of Asia include the ca. 485 Ma Duobaoshan porphyry within a part of the Tuva–Mongol arc, ca. 355 Ma low-sulfidation epithermal deposits (Kubaka) of the Omolon terrane accreted to eastern Russia, and porphyries (Bozshakol, Taldy Bulak) within Ordovican to Early Devonian oceanic arcs formed off the Kazakhstan microcontinent. The Late Devonian to Carboniferous was marked by widespread gold-rich porphyry development along the margins of the closing Ob–Zaisan, Junggar–Balkhash, and Turkestan basins (Amalyk, Oyu Tolgoi); most were formed in continental arcs, although the giant Oyu Tolgoi porphyry was part of a near-shore oceanic arc. Permian subduction-related deformation along the east side of the Indochina block led to ca. 300 Ma gold-bearing skarn and disseminated gold ore formation in the Truong Son fold belt of Laos, and along the west side to ca. 250 Ma gold-bearing skarns and epithermal deposits in the Loei fold belt of Laos and Thailand. In the Mesozoic Transbaikal region, extension along the basin margins subsequent to Mongol–Okhotsk closure was

Geology and lithogeochemistry of the Ren gold prospect, Elko County, Nevada - the role of rock sampling in exploration for deep Carlin-type deposits

USGS Publications Warehouse

Albino, G.V.

1994-01-01

The Ren gold prospect, Elko County, Nevada, is in the northern part of the Carlin trend, two kilometers northwest of the recently-discovered, high-grade Purple Vein deposit. The Ren area is underlain mainly by Paleozoic sedimentary rocks, consisting of limestone, calcareous siltstone, and mudstone of the eastern (carbonate) assemblage, overlain in thrust contact by chert, quartzite, and mudstone of the western (siliceous) assemblage. Cretaceous(?) granodiorite porphyry and hornblende porphyry dikes have intruded the sedimentary rocks along north-striking faults. Three stages of mineralization include a pre- or syntectonic base metal-barite assemblage, a middle stage of Ag- and Sb-rich jasperoid, and a late Au-rich stage responsible for the potentially economic mineralization at the prospect. The latter two stages of alteration and mineralization were focused along steep east-dipping faults and dikes, and the nearly flat-lying contact between lower massive limestone and laminated calcareous siltstone. Mineralization is present between 380 and 500 m below the surface. Alteration includes decalcification and weak silicification in siltstone, and formation of massive jasperoid in the upper part of the limestone unit. Alteration of dikes is mainly sericite-quartz-pyrite, with late pyrite-quartz-kaolinite. The element suite characteristic of Au-stage mineralization includes Au, As, and Hg with minor Ag and Hg; Ag and Sb are most enriched in the earlier jasperoid event. Haloes of As and Hg extend at least 80 m above the Au mineralization, but no anomalies are present at the surface. Gold anomalies are more widespread, and extend to shallower depths, but are less coherent. ?? 1994.

Natural factors and mining activity bearings on the water quality of the Choapa basin, North Central Chile: insights on the role of mafic volcanic rocks in the buffering of the acid drainage process.

PubMed

Parra, Amparo; Oyarzún, Jorge; Maturana, Hugo; Kretschmer, Nicole; Meza, Francisco; Oyarzún, Ricardo

2011-10-01

This contribution analyzes water chemical data for the Choapa basin, North Central Chile, for the period 1980-2004. The parameters considered are As, Cu Fe, pH, EC, SO₄⁻², Cl⁻¹, and HCO[Formula: see text], from samples taken in nine monitoring stations throughout the basin. Results show rather moderate contents of As, Cu, and Fe, with the exception of the Cuncumén River and the Aucó creek, explained by the influence of the huge porphyry copper deposit of Los Pelambres and by the presence of mining operations, respectively. When compared against results obtained in previous researches at the neighboring Elqui river basin, which host the El Indio Au-Cu-As district, a much reduced grade of pollution is recognized for the Choapa basin. Considering the effect of acid rock drainage (ARD)-related Cu contents on the fine fraction of the sediments of both river basins, the differences recorded are even more striking. Although the Los Pelambres porphyry copper deposit, on the headwaters of the Choapa river basin, is between one and two orders of magnitude bigger than El Indio, stream water and sediments of the former exhibit significantly lower copper contents than those of the latter. A main factor which may explain these results is the smaller degree of H( + )-metasomatism on the host rocks of the Los Pelambres deposit, where mafic andesitic volcanic rocks presenting propylitic hydrothermal alteration are dominant. This fact contrast with the highly altered host rocks of El Indio district, where most of them have lost their potential to neutralize ARD.

Planning of dairy farm and dairy plant based ecotourism

NASA Astrophysics Data System (ADS)

Sarnyoto, A. S.; Tama, I. P.; Tantrika, C. F. M.

2017-06-01

One of a dairy production company producing pasteurized milk and yoghurt drink, whose brand has widely known in East Java, has a factory plant in Batu City, one of tourism destinations in Indonesia. Behind the factory plant, there is a vacant land with an estimated total area of 2.3 ha and a vacant cowshed which had not been used for cattle ranching. Because of that, the company planned to develop the vacant land as a dairy farm and plant based ecotourism. In addition, dairy farm and dairy plant based tourism attractions are still rarely found in Batu. Thus, the first aim of this study was to analyse the potencies of the company that related to future plans of ecotourism built. The second aim was to set up the strategies that can be done in order to actualize the ecotourism project. The next aim was to plan the ecotourism, especially the facilities planning and the facilities arrangement on the vacant land. Strategic management approach was used to analyse the potencies and to determine the strategies. To select the proper facilities, tourists were asked to give appraisal by using questionnaire. Appraisal result was mapped onto four quadrants spatial map to see advantages and shortcomings of each facility along with choosing the right facilities to be built. Those facilities and tourist activities were compared with ecotourism criteria to make sure that the facilities were appropriate to provide not only entertainment but also ecotourism function. To arrange the chosen facilities, the step in Systematic Layout Planning were conducted to generate a propose layout of facilities arrangement. Based on potencies analysis, in Internal-External matrix, the company current position was on quadrant 2 (grow and build), with the most appropriate strategy was intensive or integrative. The proposed strategies were to build the new infrastructure, to renovate cowshed, and to add new tourism facilities on the land. There were 11 selected facilities based on MDS. Moreover, based

A Seismic Gap Study in the western offshore of Sumatra, Indonesia

NASA Astrophysics Data System (ADS)

Haridhi, H.; Rizal, S.; Ridha, M.; Lee, C. S.

2012-04-01

The extremely destructive earthquake in December 26 2004 and by the resulting tsunami was the worst natural disaster in recorded human history. However, the tsunami earthquakes continue to strike the west coast of Sumatra in the last 8 years. There were at least 12 events, the earthquake Magnitude between M = 7 to 8.9. In 2010, after 6 years of the 2004 event, an earthquake of a magnitude 7.8 resulted a destructive tsunami was also happened near Mentawai Island at West coast of West Sumatra Province. Here we present local earthquake data from local seismic network along the Sumatra region that provided by the Meteorology Climatology Geophysical Agencies of Indonesia (MCGAI). The data processing itself was started with building a minimum 1D P-wave velocity model, by using joint inversion of picked P-wave travel time; then we determined the correct relocation of the initial hypocenter provided by MCGAI. To see the spatial overview of the historical seismicity along the Sumatra subduction zone, we use IRIS-NEIC catalogue between 2004 and 2010. The result shows that there is a possible of seismic gap in the border of central - southern domain of Sumatra region. This region included in the Northern Sumatra Province near Batu Island. The historical earthquake along the Sumatra trench since 17th century showed that the last big rapture in this border of central - southern domain was occurred in 1797 by the magnitude of 8.8. In the other hand, the free-air gravity anomaly shows high values correspond to the N-S oceanic fracture zone. All the high values were found near the trench of Sumatra subduction zone and gradually lower values through the south. Regarding to the locked patches, the area below Batu Island was less coupled proposed as the result of the subducted Investigator Fracture Zone (IFZ). Through this evidence, in near future we try to investigate the P-wave velocity structure by using seismic tomographic technique. In particular, most of the events were

Geologic interpretation of geophysical data for the Wadi al Jarir and Al Jurdhawiyah quadrangles, sheets 25/42 C and D, Kingdom of Saudi Arabia

USGS Publications Warehouse

Kleinkopf, M. Dean; Cole, James C.

1983-01-01

Correlation of aeromagnetic data and mineral deposit information provide justification for some prospecting guides. Small granodiorite-porphyry plutons with distinct edge anomalies in Murdama metasediments commonly are associated with copper-gold-bearing quartz veins. Vein orientations in these and most other known deposits in the northeastern Shield cannot be sensibly related to the stress field of the Najd fault system, and are believed to predate the Najd or to have been governed by local factors. Small, weakly magnetic targets such as the Bald al Jimalah West tungsten deposit are not indicated by the regional magnetic data.

Osmium isotope constraints on ore metal recycling in subduction zones

PubMed

McInnes; McBride; Evans; Lambert; Andrew

1999-10-15

Veined peridotite xenoliths from the mantle beneath the giant Ladolam gold deposit on Lihir Island, Papua New Guinea, are 2 to 800 times more enriched in copper, gold, platinum, and palladium than surrounding depleted arc mantle. Gold ores have osmium isotope compositions similar to those of the underlying subduction-modified mantle peridotite source region, indicating that the primary origin of the metals was the mantle. Because the mantle is relatively depleted in gold, copper, and palladium, tectonic processes that enhance the advective transport and concentration of these fluid soluble metals may be a prerequisite for generating porphyry-epithermal copper-gold deposits.

Eareckson AFS, Alaska (Formerly Shemya AFB, Alaska): 1993 Installation Restoration Program Basewide and Limited Source Investigation, Work Plan

DTIC Science & Technology

1993-12-01

porphyry intrusives that crop out along the northeast and southeast shores and locally inland. Bedrock lithology is only rarely described in the borehole...kg). Groundwater samples contained arsenic (62.8 mg/L to 66.9 mg/L), chromium (19.2 mg/L to 80 mg/L), copper (52.9 mg/L to 255 mg/L), zinc (163 mg/L...0.17 mg/L; nitrate/nitrite ranging from 0.038 mg/L to 1.41 mg/L; copper at 9.6 pg/I; zinc at 13.3 pg/L; and bis (2-ethylhexyl) phthalate at 1 /ig/L

Stratigraphic setting and mineralogy of the Arctic volcanogenic massive sulfide prospect, Ambler district, Alaska.

USGS Publications Warehouse

Schmidt, J.M.

1986-01-01

The Arctic prospect, south central Brooks Range, is among the 30 largest of 508 volcanic-hosted massive sulphide deposits in the world. The massive sulphide lenses are interlayered with graphitic schist between metamorphosed rhyolite porphyries in Middle Devonian to early Mississippian metamorphosed volcanic, volcaniclastic and sedimentary rocks. Hydrothermal alteration is of three types: chloritic, phyllic s.l., and pyrite-phengite, each type strata-distinctively and respectively below, in, and above the sulphides. Maximum alteration conforms with metal zoning in the sulfides to suggest predominantly northwestward dispersal from a linear vent area in the elongate basin containing the deposit.-G.J.N.

Reconnaissance geochemical survey of the At Taif-Al Bahah region, southern Hijaz, Kingdom of Saudi Arabia

USGS Publications Warehouse

Du Bray, E.A.; Doebrich, J.L.

1982-01-01

An area south of At Taif containing significant tungsten was confirmed and found to be larger than initially determined. A possible porphyry copper pluton was discovered 50 km south-southeast of At Taif. Thirty kilometers south of At Taif, a low-grade tin anomaly associated with an S-type granite was identified. In addition, the sampling identified seven anomalous areas attributable to rock geochemically atypical of the study region. Finally, although samples from the A1 Lith-Hajrah area collected for an earlier study were found to contain anomalous concentrations of tungsten, samples collected there during this study do not support those findings.

Effect of different drying methods on concentrations of several phytochemicals in herbal preparation of 8 medicinal plants leaves.

PubMed

Mahanom, H; Azizah, A; Dzulkifly, M

1999-12-01

The effect of oven drying at 50ᵒC ± 1ᵒC for 9 hour, 70ᵒC ± 1ᵒC for 5 hour and freeze drying on retention of chlorophyll, riboflavin, niacin, ascorbic acid and carotenoids in herbal preparation consisting of 8 medicinal plants was evaluated. The medicinal plants selected were leaves of Apium graveolens (saderi), Averrhoa bilimbi (belimbing buluh), Centella asiatica (pegaga), Mentha arvensis (pudina), Psidium guajava (jambu batu), Sauropus androgynous (cekor manis), Solanum nigrum (terung meranti) and Polygonum minus (kesum ). Results revealed that both type and conditions of the drying treatments affected retention of all phytochemicals analysed. Herbal preparation developed using oven drying was found to have inferior phytochemicals content compared to that obtained by freeze dryer. Nevertheless, the herbal preparation developed using all treatments still retain appreciable amount of phytochemicals studied, especially carotenoids, ascorbic acid, niacin and riboflavin and thus have potential for commercial purposes.

Production of haploids from anther culture of banana [Musa balbisiana (BB)].

PubMed

Assani, A; Bakry, F; Kerbellec, F; Haïcour, R; Wenzel, G; Foroughi-Wehr, B

2003-02-01

We report here, for the first time, the production of haploid plants of banana Musa balbisiana (BB). Callus was induced from anthers in which the majority of the microspores were at the uninucleate stage. The frequency of callus induction was 77%. Callus proliferation usually preceded embryo formation. About 8% of the anthers developed androgenic embryos. Of the 147 plantlets obtained, 41 were haploids (n=x=11). The frequency of haploid production depended on genotypes used: 18 haploid plants were produced from genotype Pisang klutuk, 12 from Pisang batu, seven from Pisang klutuk wulung and four from Tani. The frequency of regeneration was 1.1%, which was based on the total number of anthers cultured. Diploid plants (2n=2x=22) were also observed in the regenerated plants. The haploid banana plants that were developed will be important material for the improvement of banana through breeding programmes.

Copper and Gold Partitioning Between Brine and Vapor as a Function of Reduced Sulfur

NASA Astrophysics Data System (ADS)

Ehlich, J. J.; Frank, M. R.; Bodnar, R. J.

2017-12-01

This study examined Cu and Au partitioning between sulfur-rich vapors (v) and brines (b) at conditions representative of porphyry ore deposits. Experiments were conducted at 700 °C and 100 MPa, with oxygen fugacity, f(O2), buffered by either Ni-NiO or MnO-Mn3O4. Sulfur fugacity, f(S2), was buffered by pyrrhotite + chalcopyrite or bornite + pyrrhotite + chalcopyrite mineral assemblages between log -5.6 and log 0.6. The fugacities of H2S and SO2 were calculated using the known values of fO2 and fS2. In each experiment, a gold capsule was loaded with a sulfide assemblage, a quartz core to trap fluid inclusions, and a 5 wt.% NaCl-equivalent aqueous solution containing NaCl, KCl and HCl with molar NaCl:KCl and NaCl:HCl ratios of 1 and 100, respectively. Coexisting low salinity (v) and high salinity (b) inclusions were trapped in the quartz and their salinities were estimated using microthermometry, and verified against expected salinities from the NaCl-H2O system. Na, K, Fe, Cu, and Au concentrations from 73 b and 39 v fluid inclusions were determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Nernst-style partition coefficients between b and v for a given element (Dxb/v) were determined as a function of O2, S2, H2S, and SO2 fugacities. DCub/v ranged from 2.8 to 6.6 and increased with increasing f(O2), decreased with increasing f(S2), and decreased with increasing f(H2S). Gold partition coefficients ranged from 4.6 to 8.5, with DAub/v increasing with increasing f(O2), decreasing with increasing f(S2), and decreasing with increasing f(H2S). The absolute concentrations of Cu and Au increased in both the b and v phases with increasing f(H2S), but the increase was proportionally greater in v than b. Cu and Au partitioned into b relative to v at all conditions, but Dxb/v decreased slightly with decreasing O2 or increasing S2 fugacity. Dxb/v for Cu and Au appear most strongly linked to H2S, consistently decreasing with increasing f(H2S

Geological model of supercritical geothermal reservoir related to subduction system

NASA Astrophysics Data System (ADS)

Tsuchiya, Noriyoshi

2017-04-01

Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 �

Effects Of Hydrothermal Alteration On Magnetic Properties And Magnetic Signatures - Implications For Predictive Magnetic Exploration Models

NASA Astrophysics Data System (ADS)

Clark, D.

2012-12-01

Magnetics is the most widely used geophysical method in hard rock exploration and magnetic surveys are an integral part of exploration programs for many types of mineral deposit, including porphyry Cu, intrusive-related gold, volcanic-hosted epithermal Au, IOCG, VMS, and Ni sulfide deposits. However, the magnetic signatures of ore deposits and their associated mineralized systems are extremely variable and exploration that is based simply on searching for signatures that resemble those of known deposits and systems is rarely successful. Predictive magnetic exploration models are based upon well-established geological models, combined with magnetic property measurements and geological information from well-studied deposits, and guided by magnetic petrological understanding of the processes that create, destroy and modify magnetic minerals in rocks. These models are designed to guide exploration by predicting magnetic signatures that are appropriate to specific geological settings, taking into account factors such as tectonic province; protolith composition; post-formation tilting/faulting/ burial/ exhumation and partial erosion; and metamorphism. Patterns of zoned hydrothermal alteration are important indicators of potentially mineralized systems and, if properly interpreted, can provided vectors to ore. Magnetic signatures associated with these patterns at a range of scales can provide valuable information on prospectivity and can guide drilling, provided they are correctly interpreted in geological terms. This presentation reviews effects of the important types of hydrothermal alteration on magnetic properties within mineralized systems, with particular reference to porphyry copper and IOCG deposits. For example, an unmodified gold-rich porphyry copper system, emplaced into mafic-intermediate volcanic host rocks (such as Bajo de la Alumbrera, Argentina) exhibits an inner potassic zone that is strongly mineralized and magnetite-rich, which is surrounded by an outer

Tellurium

USGS Publications Warehouse

Goldfarb, Richard J.; Berger, Byron R.; George, Micheal W.; Seal, Robert R.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Tellurium (Te) is a very rare element that averages only 3 parts per billion in Earth’s upper crust. It shows a close association with gold and may be present in orebodies of most gold deposit types at levels of tens to hundreds of parts per million. In large-tonnage mineral deposits, such as porphyry copper and seafloor volcanogenic massive sulfide deposits, sulfide minerals may contain hundreds of parts per million tellurium, although the orebodies likely have overall concentrations of 0.1 to 1.0 parts per million tellurium. Tellurium is presently recovered as a primary ore from only two districts in the world; these are the gold-tellurium epithermal vein deposits located adjacent to one another at Dashuigou and Majiagou (Sichuan Province) in southwestern China, and the epithermal-like mineralization at the Kankberg deposit in the Skellefteå VMS district of Västerbotten County, Sweden. Combined, these two groups of deposits account for about 15 percent (about 70 metric tons) of the annual global production of between 450 and 470 metric tons of tellurium. Most of the world’s tellurium, however, is produced as a byproduct of the mining of porphyry copper deposits. These deposits typically yield concentrations of 1 to 4 percent tellurium in the anode slimes recovered during copper refining. Present production of tellurium from the United States is solely from the anode slimes at ASARCO LLC’s copper refinery in Amarillo, Texas, and may total about 50 metric tons per year. The main uses of tellurium are in photovoltaic solar cells and as an additive to copper, lead, and steel alloys in various types of machinery. The environmental data available regarding the mining of tellurium are limited; most concerns to date have focused on the more-abundant metals present in the large-tonnage deposits from which tellurium is recovered as a byproduct. Global reserves of tellurium are estimated to be 24,000 metric tons, based on the amount of tellurium likely contained in

Mapping known and potential mineral occurrences and host rocks in the Bonnifield Mining District using minimal cloud- and snow-cover ASTER data: Chapter E in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

Hubbard, Bernard E.; Dusel-Bacon, Cynthia; Rowan, Lawrence C.; Eppinger, Robert G.; Gough, Larry P.; Day, Warren C.

2007-01-01

On July 8, 2003, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor acquired satellite imagery of a 60-kilometer-wide swath covering a portion of the Bonnifield mining district within the southernmost part of the Tintina Gold Province, Alaska, under unusually favorable conditions of minimal cloud and snow cover. Although rocks from more than eight different lithotectonic terranes are exposed within the extended swath of data, we focus on volcanogenic massive sulfides (VMS) and porphyry deposits within the Yukon-Tanana terrane (YTT), the largest Mesozoic accretionary terrane exposed between the Denali fault system to the south of Fairbanks and the Tintina fault system to the north of Fairbanks. Comparison of thermal-infrared region (TIR) decorrelation stretch data to available geologic maps indicates that rocks from the YTT contain a wide range of rock types ranging in composition from mafic metavolcanic rocks to felsic rock types such as metarhyolites, pelitic schists, and quartzites. The nine-band ASTER visible-near-infrared region--short-wave infrared region (VNIR-SWIR) reflectance data and spectral matched-filter processing were used to map hydrothermal alteration patterns associated with VMS and porphyry deposit types. In particular, smectite, kaolinite, opaline silica, jarosite and (or) other ferric iron minerals defined narrow (less than 250-meter diameter) zonal patterns around Red Mountain and other potential VMS targets. Using ASTER we identified some of the known mineral deposits in the region, as well as mineralogically similar targets that may represent potential undiscovered deposits. Some known deposits were not identified and may have been obscured by vegetation or snow cover or were too small to be resolved.

Geology and geochemistry of the Mammoth breccia pipe, Copper Creek mining district, southeastern Arizona: Evidence for a magmatic-hydrothermal origin

USGS Publications Warehouse

Anderson, E.D.; Atkinson, William W.; Marsh, T.; Iriondo, A.

2009-01-01

The Copper Creek mining district, southeastern Arizona, contains more than 500 mineralized breccia pipes, buried porphyry-style, copper-bearing stockworks, and distal lead-silver veins. The breccia pipes are hosted by the Copper Creek Granodiorite and the Glory Hole volcanic rocks. The unexposed Mammoth breccia pipe, solely recognized by drilling, has a vertical extent of 800 m and a maximum width of 180 m. The pipe consists of angular clasts of granodiorite cemented by quartz, chalcopyrite, bornite, anhydrite, and calcite. Biotite 40Ar/ 39Ar dates suggest a minimum age of 61.5??0.7 Ma for the host Copper Creek Granodiorite and 40Ar/39Ar dates on hydrothermal sericite indicate an age of 61.0??0.5 Ma for copper mineralization. Fluid inclusion studies suggest that a supercritical fluid with a salinity of approximately 10 wt.% NaCl equiv. condensed to a dilute aqueous vapor (1-2.8 wt.% NaCl equiv.) and a hypersaline brine (33.4-35.1 wt.% NaCl equiv.). Minimum trapping temperatures are 375??C and trapping depths are estimated at 2 km. Sulfur isotope fractionation of cogenetic anhydrite and chalcopyrite yields a temperature of mineralization of 469??25??C. Calculated oxygen and hydrogen isotope values for fluids in equilibrium with quartz and sericite range from 10.2??? to 13.4??? and -60??? to -39???, respectively, suggesting that the mineralizing fluid was dominantly magmatic. Evidence from the stable isotope and fluid inclusion analyses suggests that the fluids responsible for Cu mineralization within the Mammoth breccia pipe exsolved from a gray porphyry phase found at the base of the breccia pipe. ?? Springer-Verlag 2008.

Molybdenite in the Montezuma District of central Colorado

USGS Publications Warehouse

Neuerburg, George J.; Botinelly, Theodore; Watterson, John R.

1974-01-01

The Montezuma mining district, in the Colorado mineral belt, is defined by an assemblage of porphyry, ore, and altered rocks that originated in the venting of a Tertiary batholith through weak structures in Precambrian rocks. The ore consists of silver-lead-zinc veins clustered on the propylitic fringe of a geometrically complex system of altered rocks, which is centered on the intersection of the Oligocene Montezuma stock with the Montezuma shear zone of Precambrian ancestry. Alteration chemistry conforms to the standard porphyry-metal model but is developed around several small intrusives strung out along the shear zone and is expressed as a mottled pattern, rather than as the usual thick concentric zones centered on one large plug. The distribution of trace amounts of molybdenite is consistent with the postulate of molybdenite deposits in the district, but the mottled alteration pattern may signify small and scattered, possibly very deep, deposits. Disseminated molybdenite is essentially coextensive with altered rock and increases slightly in quantity toward the inner alteration zones. Two groups of molybdenite veins, associated with phyllic and potassic alteration, represent possible diffuse halos of molybdenite deposits. One group of veins resembles the Climax and Henderson deposits but was seen only in a small and isolated area of outcrops. The second group of molybdenite veins is in a bismuth-rich part of the Montezuma stock and underlies an area of bismuth veins; this group records the passage of contact metasomatic ore fluids. Another bismuth-rich area is in the southeast corner of the stock in a region of bismuth veins and may indicate a third group of molybdenite veins.

The return of "Gasoline station-park" status into green-open space in DKI Jakarta Province

NASA Astrophysics Data System (ADS)

Kautsar, L. H. R.; Waryono, T.; Sobirin

2017-07-01

The development of gasoline stations in 1970 increased drastically due to the Government support through DKT Jaya Official Note (DKT Jakarta), resulting in a great number of the parks (green open space or RTH - Ruang Terbuka Hijau) converted into a gasoline station. Currently, to meet the RTH target (13.94 % RTH based RTRW [(Rencana Tata Ruang Wilayah) DKT Jakarta 2010], the policy was changed by Decree No.728 year 2009 and Governor Tnstruction No.75 year 2009. Land function of 27 gasoline stations unit must be returned. This study is to determine the appropriateness of gasoline Station-Park conversion into RTH based site and situation approach. The scope of this study was limited only to gasoline stations not converted into RTH. The methodology was the combination of AHP (Analytical Hierarchy Process) and ranking method. Site variables were meant for prone to flooding, the width of land for gasoline station, land status. Situation variables were meant for other public space, availability of other gasoline stations, gasoline stations service, road segments, and the proportions of built space. Analysis study used quantitative descriptive analysis. The results were three of the five gasoline stations were congruence to be converted into a green open space (RTH).

The Use of UAV in Housing Renovation Identification: A Case Study at Taman Manis 2

NASA Astrophysics Data System (ADS)

Mustaffa, A. A.; Hasmori, M. F.; Sarif, A. S.; Ahmad, N. F.; Zainun, N. Y.

2018-04-01

Housing industry in Malaysia is growing rapidly due to the increase in population and the arising of economic level of Malaysian people. Most residential houses are built according to the standard residential design that may lead to house renovation by the buyers after purchasing the house. A method of using Unmanned Aerial Vehicle (UAV) monitoring was used to obtain information of the renovated houses directly on-site at Taman Manis 2, Parit Raja, Batu Pahat. Through comparison of image captured by the UAV with the original house plans, we found out that a total of 160 units out of 336 units of houses undergo a renovation process. Surprisingly, 41 units have been renovated illegally which has 40% to 96% of renovation rate. The acquired data were analyzed and can be concluded that the method of using UAVs to obtain information is highly recommended. The study is expected to help Municipal Council to detect improper & illegal renovation by the residents in a residential area.

Landscape Management of Public Open Space in Bogor Heritage City

NASA Astrophysics Data System (ADS)

Pusparini, F. D.; Nurhayati; Arifin, H. S.

2017-10-01

Public open space landscape plays important role in Bogor Heritage City. Although these spaces can carry various kind of public activities and enhance environment quality, they are fragile to disturbance and changing due to city development. Therefore, as an effort to maintain public open space landscape in 8 zones within Heritage City of Bogor, management of public open space landscape is necessary. Syntesys of public open space landscape management had held by using Analytical Hierarchy Process (AHP). The AHP result showed public open space landscape in Palace and Botanical Garden of Bogor zone (20%) is in high priority to be maintained. The other zone are Situ Gede (16,9%), Plan Karsten (12,3%), European Settlement (12%), Suryakencana (11,2%), Batu Tulis (10,2%), Empang (9.2%) and West Development (8,2%). Ecological function (34,8%) becomes the most important function to be maintained (34.8%) then social culture (31.2%), economic (17%), and aesthetics (17%).

Study of Car Acceleration and Deceleration Characteristics at Dangerous Route FT050

NASA Astrophysics Data System (ADS)

Omar, N.; Prasetijo, J.; Daniel, B. D.; Abdullah, M. A. E.; Ismail, I.

2018-04-01

Individual vehicle acceleration and deceleration are important to generate vehicles speed profile. This study covered acceleration and deceleration characteristics of passenger car in Federal Route FT050 Jalan Batu Pahat-Ayer Hitam that was the top ranking dangerous road. Global Positioning System was used to record 10 cars speed to develop speed profile with clustering zone. At the acceleration manoeuver, the acceleration rate becomes lower as the drivers get near to desired speed. While, at deceleration manoeuver, vehicles with high speed needs more time to stop compare to low speed vehicle. This is because, the drivers need to accelerate more from zero speed to achieve desired speed and drivers need more distance and time to stop their vehicles. However, it was found out that 30% to 50% are driving in dangerous condition that was proven in clustering acceleration and deceleration speed profile. As conclusion, this excessive drivers are the factor that creating high risk in rear-end collision that inline FT050 as dangerous road in Malaysia

Effects of Hydrological Parameters on Palm Oil Fresh Fruit Bunch Yield)

NASA Astrophysics Data System (ADS)

Nda, M.; Adnan, M. S.; Suhadak, M. A.; Zakaria, M. S.; Lopa, R. T.

2018-04-01

Climate change effects and variability have been studied by many researchers in diverse geophysical fields. Malaysia produces large volume of palm oil, the effects of climate change on hydrological parameters (rainfall and precipitation) could have adverse effects on palm oil fresh fruit bunch (FFB) production with implications at both local and international market. It is important to understand the effects of climate change on crop yield to adopt new cultivation techniques and guaranteeing food security globally. Based on this background, the paper’s objective is to investigate the effects of rainfall and temperature pattern on crop yield (FFB) within five years period (2013 - 2017) at Batu Pahat District. The Man - Kendall rank technique (trend test) and statistical analyses (correlation and regression) were applied to the dataset used for the study. The results reveal that there are variabilities in rainfall and temperature from one month to the other and the statistical analysis reveals that the hydrological parameters have an insignificant effect on crop yield.

ARNOLD MESA ROADLESS AREA, ARIZONA.

USGS Publications Warehouse

Wolfe, Edward W.; McColly, Robert A.

1984-01-01

Geologic geochemical, and aeromagnetic investigations and a survey of mines and prospects in the Arnold Mesa Roadless Area, Arizona, provide little evidence for the occurrence of mineral or energy resources. Buried Proterozoic basement rocks are possible hosts of porphyry-type copper and massive sulfide deposits but the thick cover of Paleozoic sedimentary rocks and upper Cenozoic volcanic rocks precluded assessment of this possibility. Chemistry and temperature of spring and well waters suggest that a geothermal resource may exist near the eastern margin of the roadless area, but the anomaly has not been tested by drilling and this resource remains unverified. No other energy resources were identified.

Detection of alteration associated with a porphyry copper deposit in southern Arizona

NASA Technical Reports Server (NTRS)

Abrams, M. J.; Siegal, B. S.

1977-01-01

Computer processing of Landsat MSS data was performed using contrast stretching and band-to-band ratioing. A false color ratio composite picture showed color anomalies which coincided with known areas of alteration on and about Red Mountain. A helicopter survey of the study area was undertaken using a portable field reflectance spectrometer. One hundred fifty-six spectra were obtained in the 0.4 to 2.5 micrometer wavelength region. The spectra were digitized, and contour maps for 24 wavelength intervals were produced; no spectral anomalies were evident for the known altered areas. A contour map produced from the 1.6 and 2.2 micrometer ratio generally delineated the alteration areas. The 1.3, 1.6, and 2.2 micrometer wavelength data were canonically transformed using a transformation empirically derived from discriminant function analysis of altered and unaltered materials for the Goldfield, Nevada region, and a contour map was produced for the first canonical variable. The known areas of alteration were clearly defined on the contour map.

Recognition of the geologic framework of porphyry deposits on ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Wilson, J. C. (Principal Investigator); Camp, L. W.

1973-01-01

The author has identified the following significant results. Preliminary analysis of a mosaic composing 20 individual ERTS-1 frames that covers most of Nevada and western Utah reveals both new and old structural features. Three separate provinces, the Basin and Range, the southern extension of the Columbia River Plateau volcanics, and the western edge of the Colorado Plateau are easily distinguishable. A west-northwest cross or transverse structural trend, the Las Vegas Shear zone, is present in the region running from the Sierra Nevada to Lake Mead. The Sevier, Hurricane and Grand Wash faults that define the Wasateh-Jerome structural zone, can be traced further on the ERTS-1 imagery than on existing tectonic maps. By use of a stereo viewer on the side-lap coverage of ERTS-1 imagery, it is possible in some instances to determine the direction of sedimentary beds, enabling anticlines and synclines to be mapped. Other geologic features, faults, direction of throw on faults, recent basalt flow contacts with older rhyolitic tuffs, volcanic cones, and subsidences can also be mapped.

Rhenium in ores of the Mikheevskoe porphyry Cu-Mo deposit, South Urals

NASA Astrophysics Data System (ADS)

Plotinskaya, O. Yu.; Grabezhev, A. I.; Seltmann, R.

2015-03-01

The distribution of Re in ores of the Mikheevskoe Mo-Cu deposit in the South Urals is studied. It is established that the grade of Re in the ores usually does not exceed 0.5 g/t. A positive correlation between concentrations of Re and Mo (correlation coefficient 0.94), and Re and Cu (correlation coefficient 0.52) is found. EMPA of individual flakes of molybdenite showed that a Re content higher than the detection limit has been measured in most flakes studied, as a rule as high as 0.4-0.5 wt %, but occasionally reaching 1.34 wt %. Re within flakes of molybdenite is irregularly distributed. Patchy, linear, and concentric-zoned patterns of zones with elevated Re content (usually 0.5-1 wt % Re, sometimes higher) are found against the lower content (up to 0.2 wt % Re) that is regularly distributed within the flake. Later hydrothermal processes and mechanical deformation of flakes result in epigenetic Re redistribution in molybdenite that leads to homogenization of molybdenite composition and smoothing of primary pattern, or removal of Re from molybdenite.

Intrusive rocks northeast of Steamboat Springs, Park Range, Colorado, with a section on geochronology

USGS Publications Warehouse

Snyder, George L.; Hedge, Carl E.

1978-01-01

Major Precambrian and minor Tertiary intrusive rocks northeast of Steamboat Springs in the Park Range between 40?30' and 40?45' N. lat. are described and compared with related rocks elsewhere in Colorado and Wyoming. The Precambrian intrusives were emplaced in a sequence of high-grade interlayered felsic gneisses, amphibolites, and pelitic schists of sedimentary and volcanic origin. These rocks are cut by a major northeast-trending Precambrian shear zone where mainly left lateral movement of 1/ 2 to 1 mile is certain. Cumulative movement of many miles is possible. The Precambrian intrusives consist of a batholith, the Mount Ethel pluton, a smaller Buffalo Pass pluton, and small dikes or lenses of fine-grained porphyry, pegmatites, and ultramafics. The Mount Ethel pluton is an oval shaped body 7 miles wide by about 40 miles long (shown by geophysical data to extend beneath younger sediments in North Park). Outer batholithic contacts are sharp and dip steeply outward at about 85?. Five mappable internal variants consist, in order of decreasing age, of granodiorite, quartz monzonite porphyry of Rocky Peak, quartz monzonite of Roxy Ann Lake, granite and quartz monzonite, and. leucogranite. Internal contacts between these plutonic variants are sharp, and evidence of liquid-solid relationships abounds; despite this, all rocks except the granodiorite contribute to an Rb-Sr whole-rock isochron indicating emplacement about 1.4 b.y. (billion years) ago. The most important variants volumetrically are: the quartz monzonite porphyry of Rocky Peak, which forms an irregular 2-mile-thick carapace or mapped band around the west edge of the pluton and is lithologically similar to nearby Sherman Granite, and the quartz monzonite of Roxy Ann Lake, which forms most of the rest of the pluton and is lithologically similar to Silver Plume Granite. An apparent Sherman -Silver Plume dichotomy with similar rock types and similar relative ages is noted throughout Colorado plutons of that age

Self-Ordering and Complexity in Epizonal Mineral Deposits

NASA Astrophysics Data System (ADS)

Henley, Richard W.; Berger, Byron R.

Epizonal base and precious metal deposits makeup a range of familiar deposit styles including porphyry copper-gold, epithermal veins and stockworks, carbonate-replacement deposits, and polymetallic volcanic rock-hosted (VHMS) deposits. They occur along convergent plate margins and are invariably associated directly with active faults and volcanism. They are complex in form, variable in their characteristics at all scales, and highly localized in the earth's crust. More than a century of detailed research has provided an extensive base of observational data characterizing these deposits, from their regional setting to the fluid and isotope chemistry of mineral deposition. This has led to a broad understanding of the large-scale hydrothermal systems within which they form. Low salinity vapor, released by magma crystallization and dispersed into vigorously convecting groundwater systems, is recognized as a principal source of metals and the gases that control redox conditions within systems. The temperature and pressure of the ambient fluid anywhere within these systems is close to its vapor-liquid phase boundary, and mineral deposition is a consequence of short timescale perturbations generated by localized release of crustal stress. However, a review of occurrence data raises questions about ore formation that are not addressed by traditional genetic models. For example, what are the origins of banding in epithermal veins, and what controls the frequency of oscillatory lamination? What controls where the phenomenon of mineralization occurs, and why are some porphyry deposits, for example, so much larger than others? The distinctive, self-organized characteristics of epizonal deposits are shown to be the result of repetitive coupling of fracture dilation consequent on brittle failure, phase separation ("boiling"), and heat transfer between fluid and host rock. Process coupling substantially increases solute concentrations and triggers fast, far

Role of Mineral Deposits in Global Geochemical Cycles

NASA Astrophysics Data System (ADS)

Kesler, S.; Wilkinson, B.

2009-12-01

Mineral deposits represent the most extreme degree of natural concentration for most elements and their formation and destruction are important parts of global geochemical cycles. Quantitative estimates of the role that mineral deposits play in these geochemical cycles has been limited, however, by the lack of information on actual amounts of elements that are concentrated in these deposits, and their rates of formation and destruction at geologic time scales. Recent use of a “tectonic diffusion” model for porphyry copper deposits, the most important source of world copper, in conjunction with estimates of their copper content (Kesler and Wilkinson, 2008), allows an assessment of the role of copper deposits in Earth’s global copper cycles. These results indicate that ~4.5*10^8 Gg of Cu have been concentrated in porphyry copper deposits through Phanerozoic time, that deposits containing ~2.8*10^8 Gg of Cu have been removed by uplift and erosion over the same time period, and that deposits containing ~1.7*10^8 Gg remain in Earth’s crust. If styles of formation and destruction of other copper-bearing mineral deposits are similar, then all crustal deposits contain ~3*10^8 Gg of copper. This constitutes about 0.03% of the copper that resides in crustal rocks and provides a first-ever estimate of the rate at which natural geochemical cycles produce the extreme concentrations that constitute mineral deposits. Another ~8*10^8 Gg of copper have been destroyed during the uplift and erosion of mineral deposits over Phanerozoic time, a flux amounting to an annual contribution of about 1.5 Gg of copper to the near-surface environment. This amount is similar in magnitude to copper released by volcanic outgassing, but only ~2.5% of the 56 Gg of copper estimated to be released annually by weathering of average crustal rocks (Rauch and Graedel, 2007). The amount of copper removed from mineral deposits by mining, 1.1*10^4 Gg/year, is much larger than any natural

Late Paleozoic tectonic evolution and concentrated mineralization in Balkhash and West Junggar, western part of the Central Asian Orogenic Belt

NASA Astrophysics Data System (ADS)

Dong, Shuwen; Chen, Xuanhua; Chen, Zhengle

2016-04-01

The Central Asia Orogenic Belt (CAOB) is an important area with significant growth of the crust and metallogeny in the Late Paleozoic. The Balkhash-Junggar tectono-metallogenic belt consists of the Balkhash, the West Junggar, and the East Junggar tectono-metallogenic belts in western part of the Central Asian Orogenic Belt (CAOB). According to the structural geological relationship, the East Junggar, the West Junggar, and the Balkhash belts are considered to be once a continuous E-W-trending tectono-metallogenic belt in Late Carboniferous. The West Junggar belt is featured with NE-trending left-lateral strike-slip faulting tectonic system (WJTS), while the left-lateral strike-slip faults are E-W-trending in the Balkhash belt. The WJTS consists of the Darabut, the Mayile, and the Baerluke faults, and the blocks among them. All these left-lateral strike-slip faults are forming due to the transition of tectonic settings from syn-collisional orogeny to post-collisional extension during the closure of the ocean (the Junggar Sea) in Late Carboniferous, with significant intrusion of batholiths and crust growth occurred in this period. These faults are truncated by the right-lateral strike-slip faults, such as the Chingiz-Junggar fault, and the Central Balkhash fault in Mesozoic. The Balkhash-Junggar tectono-metallogenic belt is important for the occurrence of many well-known super-large and large porphyry Cu-Mo deposits (such as the Kounrad, the Aktogai, the Borly, and the Baogutu deposits), large skarn Cu deposits (in the Sayak ore-filed), large rare metal deposits (such as the East Kounrad, the Zhanet, and the Akshatau deposits), and large gold deposits (such as the Hatu deposit). Zircon U-Pb ages, Re-Os isotopic dating of molybdenites, 40Ar/39Ar thermochronology of hornblendes, muscovites, biotites, and K-feldspars, and zircon and apatite fission track (FT) and (U-Th)/He dating and thermal history modeling, provide a multidisciplinary approach to constrain the whole

Gold deposits of the Carolina Slate Belt, southeastern United States--Age and origin of the major gold producers

USGS Publications Warehouse

Foley, Nora K.; Ayuso, Robert A.

2012-01-01

Gold- and iron sulfide-bearing deposits of the southeastern United States have distinctive mineralogical and geochemical features that provide a basis for constructing models of ore genesis for exploration and assessment of gold resources. The largest (historic) deposits, in approximate million ounces of gold (Moz Au), include those in the Haile (~ 4.2 Moz Au), Ridgeway (~1.5 Moz Au), Brewer (~0.25 Moz Au), and Barite Hill (0.6 Moz Au) mines. Host rocks are Late Proterozoic to early Paleozoic (~553 million years old) metaigneous and metasedimentary rocks of the Carolina Slate Belt that share a geologic affinity with the classic Avalonian tectonic zone. The inferred syngenetic and epithermal-subvolcanic quartz-porphyry settings occur stratigraphically between sequences of metavolcanic rocks of the Persimmon Fork and Uwharrie Formations and overlying volcanic and epiclastic rocks of the Tillery and Richtex Formations (and regional equivalents). The Carolina Slate Belt is highly prospective for many types of gold ore hosted within quartz-sericite-pyrite altered volcanic rocks, juvenile metasedimentary rocks, and in associated shear zones. For example, sheared and deformed auriferous volcanogenic massive sulfide deposits at Barite Hill, South Carolina, and in the Gold Hill trend, North Carolina, are hosted primarily by laminated mudstone and felsic volcanic to volcaniclastic rocks. The high-sulfidation epithermal style of gold mineralization at Brewer and low-sulfidation gold ores of the Champion pit at Haile occur in breccias associated with subvolcanic quartz porphyry and within crystal-rich tuffs, ash flows, and subvolcanic rhyolite. The Ridgeway and Haile deposits are primarily epithermal replacements and feeder zones within (now) metamorphosed crystal-rich tuffs, volcaniclastic sediments, and siltstones originally deposited in a marine volcanic-arc basinal setting. Recent discoveries in the region include (1) extensions of known deposits, such as at Haile where

Geochronology, fluid inclusions and isotopic characteristics of the Chaganbulagen Pb-Zn-Ag deposit, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Li, Tiegang; Wu, Guang; Liu, Jun; Wang, Guorui; Hu, Yanqing; Zhang, Yunfu; Luo, Dafeng; Mao, Zhihao; Xu, Bei

2016-09-01

The large Chaganbulagen Pb-Zn-Ag deposit is located in the Derbugan metallogenic belt of the northern Great Xing'an Range. The vein-style orebodies of the deposit occur in the NWW-trending fault zones. The ore-forming process at the deposit can be divided into three stages: an early quartz-pyrite-arsenopyrite-pyrrhotite-sphalerite-galena-chalcopyrite stage, a middle quartz-carbonate-pyrite-sphalerite-galena-silver-bearing minerals stage, and a late quartz-carbonate-pyrite stage. The sericite sample yielded a 40Ar -39Ar plateau age of 138 ± 1 Ma and an isochron age of 137 ± 3 Ma, and the zircon LA-ICP-MS U-Pb age of monzogranite porphyry was 143 ± 2 Ma, indicating that the ages of mineralization and monzogranite porphyry in the Chaganbulagen deposit should be the Early Cretaceous, and that the mineralization should be slightly later than the intrusion of monzogranite porphyry. There are only liquid inclusions in quartz veins of the Chaganbulagen deposit. Homogenization temperatures, densities, and salinities of the fluid inclusions from the early stage are 261-340 °C, 0.65-0.81 g/cm3, and 0.7-6.3 wt.% NaCl eqv., respectively. Fluid inclusions of the middle stage have homogenization temperatures, densities, and salinities of 209-265 °C, 0.75-0.86 g/cm3, and 0.5-5.7 wt.% NaCl eqv., respectively. For fluid inclusions of the late stage, their homogenization temperatures, densities, and salinities are 173-219 °C, 0.85-0.91 g/cm3, and 0.4-2.7 wt.% NaCl eqv., respectively. The ore-forming fluids of the deposit are generally characterized by moderate temperature and low salinity and density, and belong to an H2O-NaCl ± CO2 ± CH4 system. The δ18Owater values calculated for ore-bearing quartz vary from - 17.9‰ to - 10.8‰, and the δDV-SMOW values from bulk extraction of fluid inclusion waters vary from - 166‰ to - 127‰, suggesting that the ore-forming fluids consist dominantly of meteoric water. The δ34SV-CDT values range from 1.4‰ to 4.1‰. The 206Pb/204

Trace element geochemistry of zircons from mineralizing and non-mineralizing igneous rocks related to gold ores at Yanacocha, Peru

NASA Astrophysics Data System (ADS)

Koleszar, A. M.; Dilles, J. H.; Kent, A. J.; Wooden, J. L.

2012-12-01

Zircons record important details about the evolution of magmatic systems, are relatively insensitive to alteration, and have been used to investigate the geochemistry, temperature, and oxidation state of volcanic and plutonic system. We examine zircons that span 6-7 m.y. of calc-alkaline volcanic activity in the Yanacocha district of northern Peru, where dacitic intrusions are associated with high-sulfidation gold deposits. The 14.5-8.4 Ma Yanacocha Volcanics include cogenetic lavas and pyroclastic rocks and are underlain by the andesites and dacites of the Calipuy Group, the oldest Cenozoic rocks in the region. We present data for magmatic zircons from the Cerro Fraile dacitic pyroclastics (15.5-15.1 Ma) of the Calipuy Group, and multiple eruptive units within the younger Yanacocha Volcanics: the Atazaico Andesite (14.5-13.3 Ma), the Quilish Dacite (~14-12 Ma), the Azufre Andesite (12.1-11.6 Ma), the San Jose Ignimbrite (11.5-11.2 Ma), and the Coriwachay Dacite (11.1-8.4 Ma). Epithermal high sulfidation (alunite-bearing) gold deposits are associated with the dacite intrusions of the Coriwachay and Quilish Dacites. Zircons from the non-mineralizing rocks typically have lower Hf concentrations and record Ti-in-zircon temperatures that are ~100°C hotter than zircons from the mineralizing intrusions. Temperatures recorded by zircons from the mineralizing intrusions are remarkably similar to those of the underlying Cerro Fraile dacite pyroclastics, but the zircons discussed here generally record SHRIMP-RG 206Pb/238U ages within error of previously published Ar-Ar eruption ages (eliminating antecrystic or xenocrystic origins). These observations suggest that zircons in the mineralizing intrusions form after greater extents of crystallization (and thus record elevated Hf concentrations and lower temperatures) than do zircons in the non-mineralized deposits. Unlike zircons from mineralized units associated with the porphyry Cu(Mo) deposits in Yerington, Nevada, which

Unravelling the depositional origins and diagenetic alteration of carbonate breccias

NASA Astrophysics Data System (ADS)

Madden, Robert H. C.; Wilson, Moyra E. J.; Mihaljević, Morana; Pandolfi, John M.; Welsh, Kevin

2017-07-01

Carbonate breccias dissociated from their platform top counterparts are little studied despite their potential to reveal the nature of past shallow-water carbonate systems and the sequential alteration of such systems. A petrographic and stable isotopic study allowed evaluation of the sedimentological and diagenetic variability of the Cenozoic Batu Gading Limestone breccia of Borneo. Sixteen lithofacies representing six facies groups have been identified mainly from the breccia clasts on the basis of shared textural and compositional features. Clasts of the breccia are representative of shallow carbonate platform top and associated flank to basinal deposits. Dominant inputs are from rocky (karstic) shorelines or localised seagrass environments, coral patch reef and larger foraminiferal-rich deposits. Early, pre-brecciation alteration (including micritisation, rare dissolution of bioclasts, minor syntaxial overgrowth cementation, pervasive neomorphism and calcitisation of bioclasts and matrix) was mainly associated with marine fluids in a near surface to shallow burial environment. The final stages of pre-brecciation diagenesis include mechanical compaction and cementation of open porosity in a shallow to moderate depth burial environment. Post-brecciation diagenesis took place at increasingly moderate to deep burial depths under the influence of dominantly marine burial fluids. Extensive compaction, circum-clast dissolution seams and stylolites have resulted in a tightly fitted breccia fabric, with some development of fractures and calcite cements. A degree of facies-specific controls are evident for the pre-brecciation diagenesis. Pervasive mineralogical stabilisation and cementation have, however, led to a broad similarity of diagenetic features in the breccia clasts thereby effectively preserving depositional features of near-original platform top and margin environments. There is little intra-clast alteration overprint associated with subsequent clast reworking

Timing of multiple hydrothermal events in the iron oxide-copper-gold deposits of the Southern Copper Belt, Carajás Province, Brazil

NASA Astrophysics Data System (ADS)

Moreto, Carolina P. N.; Monteiro, Lena V. S.; Xavier, Roberto P.; Creaser, Robert A.; DuFrane, S. Andrew; Melo, Gustavo H. C.; Delinardo da Silva, Marco A.; Tassinari, Colombo C. G.; Sato, Kei

2015-06-01

The Southern Copper Belt, Carajás Province, Brazil, hosts several iron oxide-copper-gold (IOCG) deposits, including Sossego, Cristalino, Alvo 118, Bacuri, Bacaba, Castanha, and Visconde. Mapping and U-Pb sensitive high-resolution ion microprobe (SHRIMP) IIe zircon geochronology allowed the characterization of the host rocks, situated within regional WNW-ESE shear zones. They encompass Mesoarchean (3.08-2.85 Ga) TTG orthogneiss, granites, and remains of greenstone belts, Neoarchean (ca. 2.74 Ga) granite, shallow-emplaced porphyries, and granophyric granite coeval with gabbro, and Paleoproterozoic (1.88 Ga) porphyry dykes. Extensive hydrothermal zones include albite-scapolite, biotite-scapolite-tourmaline-magnetite alteration, and proximal potassium feldspar, chlorite-epidote and chalcopyrite formation. U-Pb laser ablation multicollector inductively coupled mass spectrometry (LA-MC-ICP-MS) analysis of ore-related monazite and Re-Os NTIMS analysis of molybdenite suggest multiple Neoarchean (2.76 and 2.72-2.68 Ga) and Paleoproterozoic (2.06 Ga) hydrothermal events at the Bacaba and Bacuri deposits. These results, combined with available geochronological data from the literature, indicate recurrence of hydrothermal systems in the Southern Copper Belt, including 1.90-1.88-Ga ore formation in the Sossego-Curral ore bodies and the Alvo 118 deposit. Although early hydrothermal evolution at 2.76 Ga points to fluid migration coeval with the Carajás Basin formation, the main episode of IOCG genesis (2.72-2.68 Ga) is related to basin inversion coupled with Neoarchean (ca. 2.7 Ga) felsic magmatism. The data suggest that the IOCG deposits in the Southern Copper Belt and those in the Northern Copper Belt (2.57-Ga Salobo and Igarapé Bahia-Alemão deposits) do not share a common metallogenic evolution. Therefore, the association of all IOCG deposits of the Carajás Province with a single extensive hydrothermal system is precluded.

Mineral deposit densities for estimating mineral resources

USGS Publications Warehouse

Singer, Donald A.

2008-01-01

Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits, the density of deposits (deposits/area) in well-explored control areas can serve to represent the number of deposits. Empirical evidence presented here indicates that the processes affecting the number and quantity of resources in geological settings are very general across many types of mineral deposits. For podiform chromite, porphyry copper, and volcanogenic massive sulfide deposit types, the size of tract that geologically could contain the deposits is an excellent predictor of the total number of deposits. The number of mineral deposits is also proportional to the type’s size. The total amount of mineralized rock is also proportional to size of the permissive area and the median deposit type’s size. Regressions using these variables provide a means to estimate the density of deposits and the total amount of mineralization. These powerful estimators are based on analysis of ten different types of mineral deposits (Climax Mo, Cuban Mn, Cyprus massive sulfide, Franciscan Mn, kuroko massive sulfide, low-sulfide quartz-Au vein, placer Au, podiform Cr, porphyry Cu, and W vein) from 108 permissive control tracts around the world therefore generalizing across deposit types. Despite the diverse and complex geological settings of deposit types studied here, the relationships observed indicate universal controls on the accumulation and preservation of mineral resources that operate across all scales. The strength of the relationships (R 2=0.91 for density and 0.95 for mineralized rock) argues for their broad use. Deposit densities can now be used to provide a guideline for expert judgment or used directly for estimating the number of most kinds of mineral deposits.

Groundwater resources of the East Mountain area, Bernalillo, Sandoval, Santa Fe, and Torrance Counties, New Mexico, 2005

USGS Publications Warehouse

Bartolino, James R.; Anderholm, Scott K.; Myers, Nathan C.

2010-01-01

The groundwater resources of about 400 square miles of the East Mountain area of Bernalillo, Sandoval, Santa Fe, and Torrance Counties in central New Mexico were evaluated by using groundwater levels and water-quality analyses, and updated geologic mapping. Substantial development in the study area (population increased by 11,000, or 50 percent, from 1990 through 2000) has raised concerns about the effects of growth on water resources. The last comprehensive examination of the water resources of the study area was done in 1980-this study examines a slightly different area and incorporates data collected in the intervening 25 years. The East Mountain area is geologically and hydrologically complex-in addition to the geologic units, such features as the Sandia Mountains, Tijeras and Gutierrez Faults, Tijeras syncline and anticline, and the Estancia Basin affect the movement, availability, and water quality of the groundwater system. The stratigraphic units were separated into eight hydrostratigraphic units, each having distinct hydraulic and chemical properties. Overall, the major hydrostratigraphic units are the Madera-Sandia and Abo-Yeso; however, other units are the primary source of supply in some areas. Despite the eight previously defined hydrostratigraphic units, water-level contours were drawn on the generalized regional potentiometric map assuming all hydrostratigraphic units are connected and function as a single aquifer system. Groundwater originates as infiltration of precipitation in upland areas (Sandia, Manzano, and Manzanita Mountains, and the Ortiz Porphyry Belt) and moves downgradient into the Tijeras Graben, Tijeras Canyon, San Pedro synclinorium, and the Hagan, Estancia, and Espanola Basins. The study area was divided into eight groundwater areas defined on the basis of geologic, hydrologic, and geochemical information-Tijeras Canyon, Cedar Crest, Tijeras Graben, Estancia Basin, San Pedro Creek, Ortiz Porphyry Belt, Hagan Basin, and Upper Sandia

Earth Observations taken by the Expedition 16 Crew

NASA Image and Video Library

2008-03-05

ISS016-E-031056 (3 March 2008) --- Cananea Copper Mine, Sonora, Mexico is featured in this image photographed by an Expedition 16 crewmember on the International Space Station. One of the largest open-pit copper mines in the world, the Cananea mine produced over 164,000 tons of copper in 2006. The mine is located approximately 40 kilometers south of the border between the USA (Arizona) and Mexico (Sonora). Copper and gold ores at Cananea are found in a porphyry copper deposit, a geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. A porphyry - an igneous rock with large crystals in a fine-grained matrix -- is formed as the magma cools and crystallizes. While crystallization is occurring, hot fluids can circulate through the magma and surrounding rocks via fractures. This hydrothermal alteration of the rocks typically forms copper-bearing and other minerals. Much of the Cananea mine's ore is concentrated in breccia pipes -- mineralized rod or chimney-shaped bodies that contain broken rock fragments. The active, two-kilometers-in-diameter Colorada Pit (top right) is recognizable in this image by the concentric steps or benches cut around its perimeter. These benches allow for access into the pit for extraction of ore and waste materials. Water (black) is visible filling the bottom of the pit, and several other basins in the surrounding area. The city of Cananea -- marked by its street grid -- is located to the northeast of the mine workings. A leachate reservoir is located to the east of the mine (lower left) for removal and evaporation of water pumped from the mine workings -- the bluish-white coloration of deposits near the reservoir suggests the high mineral content of the leachate. A worker strike halted mine operations in 2007.

Age constraints on the hydrothermal history of the Prominent Hill iron oxide copper-gold deposit, South Australia

NASA Astrophysics Data System (ADS)

Bowden, Bryan; Fraser, Geoff; Davidson, Garry J.; Meffre, Sebastien; Skirrow, Roger; Bull, Stuart; Thompson, Jay

2017-08-01

The Mesoproterozoic Prominent Hill iron-oxide copper-gold deposit lies on the fault-bound southern edge of the Mt Woods Domain, Gawler Craton, South Australia. Chalcocite-bornite-chalcopyrite ores occur in a hematitic breccia complex that has similarities to the Olympic Dam deposit, but were emplaced in a shallow water clastic-carbonate package overlying a thick andesite-dacite pile. The sequence has been overturned against the major, steep, east-west, Hangingwall Fault, beyond which lies the clastic to potentially evaporitic Blue Duck Metasediments. Immediately north of the deposit, these metasediments have been intruded by dacite porphyry and granitoid and metasomatised to form magnetite-calc-silicate skarn ± pyrite-chalcopyrite. The hematitic breccia complex is strongly sericitised and silicified, has a large sericite ± chlorite halo, and was intruded by dykes during and after sericitisation. This paper evaluates the age of sericite formation in the mineralised breccias and provides constraints on the timing of granitoid intrusion and skarn formation in the terrain adjoining the mineralisation. The breccia complex contains fragments of granitoid and porphyry that are found here to be part of the Gawler Range Volcanics/Hiltaba Suite magmatic event at 1600-1570 Ma. This indicates that some breccia formation post-dated granitoid intrusion. Monazite and apatite in Fe-P-REE-albite metasomatised granitoid, paragenetically linked with magnetite skarn formation north of the Hangingwall Fault, grew soon after granitoid intrusion, although the apatite experienced U-Pb-LREE loss during later fluid-mineral interaction; this accounts for its calculated age of 1544 ± 39 Ma. To the south of the fault, within the breccia, 40Ar-39Ar ages yield a minimum age of sericitisation (+Cu+Fe+REE) of dykes and volcanics of ˜1575 Ma, firmly placing Prominent Hill ore formation as part of the Gawler Range Volcanics/Hiltaba Suite magmatic event within the Olympic Cu-Au province of the

Mineral Deposit Data for Epigenetic Base- and Precious-metal and Uranium-thorium Deposits in South-central and Southwestern Montana and Southern and Central Idaho

USGS Publications Warehouse

Klein, T.L.

2004-01-01

Metal deposits spatially associated with the Cretaceous Boulder and Idaho batholiths of southwestern Montana and southern and central Idaho have been exploited since the early 1860s. Au was first discovered in placer deposits; exploitation of vein deposits in bedrock soon followed. In 1865, high-grade Ag vein deposits were discovered and remained economically important until the 1890s. Early high-grade deposits of Au, Ag and Pb were found in the weathered portions of the veins systems. As mining progressed to deeper levels, Ag and Pb grades diminished. Exploration for and development of these vein deposits in this area have continued until the present. A majority of these base- and precious-metal vein deposits are classified as polymetallic veins (PMV) and polymetallic carbonate-replacement (PMR) deposits in this compilation. Porphyry Cu and Mo, epithermal (Au, Ag, Hg and Sb), base- and precious-metal and W skarn, W vein, and U and Th vein deposits are also common in this area. The world-class Butte Cu porphyry and the Butte high-sulfidation Cu vein deposits are in this study area. PMV and PMR deposits are the most numerous in the region and constitute about 85% of the deposit records compiled. Several types of syngenetic/diagenetic sulfide mineral deposits in rocks of the Belt Supergroup or their equivalents are common in the region and they have been the source of a substantial metal production over the last century. These syngenetic deposits and their metamorphosed/structurally remobilized equivalents were not included in this database; therefore, deposits in the Idaho portion of the Coeur d'Alene district and the Idaho Cobalt belt, for example, have not been included because many of them are believed to be of this type.

Spatial database for a global assessment of undiscovered copper resources: Chapter Z in Global mineral resource assessment

USGS Publications Warehouse

Dicken, Connie L.; Dunlap, Pamela; Parks, Heather L.; Hammarstrom, Jane M.; Zientek, Michael L.; Zientek, Michael L.; Hammarstrom, Jane M.; Johnson, Kathleen M.

2016-07-13

As part of the first-ever U.S. Geological Survey global assessment of undiscovered copper resources, data common to several regional spatial databases published by the U.S. Geological Survey, including one report from Finland and one from Greenland, were standardized, updated, and compiled into a global copper resource database. This integrated collection of spatial databases provides location, geologic and mineral resource data, and source references for deposits, significant prospects, and areas permissive for undiscovered deposits of both porphyry copper and sediment-hosted copper. The copper resource database allows for efficient modeling on a global scale in a geographic information system (GIS) and is provided in an Esri ArcGIS file geodatabase format.

Typing mineral deposits using their associated rocks, grades and tonnages using a probabilistic neural network

USGS Publications Warehouse

Singer, D.A.

2006-01-01

A probabilistic neural network is employed to classify 1610 mineral deposits into 18 types using tonnage, average Cu, Mo, Ag, Au, Zn, and Pb grades, and six generalized rock types. The purpose is to examine whether neural networks might serve for integrating geoscience information available in large mineral databases to classify sites by deposit type. Successful classifications of 805 deposits not used in training - 87% with grouped porphyry copper deposits - and the nature of misclassifications demonstrate the power of probabilistic neural networks and the value of quantitative mineral-deposit models. The results also suggest that neural networks can classify deposits as well as experienced economic geologists. ?? International Association for Mathematical Geology 2006.

Deterioration Types of Stones Used in Suleymaniye Mosque (Istanbul, Turkey)

NASA Astrophysics Data System (ADS)

Alptekin Bilen, Candan; Erisis, Sinem; Er, Selman; Yilmaz, Murat; Angi, Serkan; Tugrul, Atiye

2016-10-01

Suleymaniye Mosque located in the historic peninsula of Istanbul, is one of the most important monument of classical Ottoman Architecture. Different types of natural stones having varied lithological characteristics were used in the mosque. Chemical composition, mineralogical, petrographic characteristics and external conditions such as atmospheric effects, earthquake and human impacts have deteriorated these stones over time. The aim of this study is to investigate different natural stones and their deterioration types used in Suleymaniye Mosque. According to the results obtained, generally different types of granites, marbles, limestones, pudding stones, porphyry, serpentinite were used in Suleymaniye Mosque. Detachment, material loss, biological colonization, discoloration and deposits have been determined as a deterioration types on these stones.

Mineral resource potential map of the Gila-San Francisco Wilderness Study Area, Graham and Greenlee counties, Arizona

USGS Publications Warehouse

Richter, Donlad H.; Klein, Douglas P.; Lawrence, Viki A.; Lane, Michael

1982-01-01

The mineral resource potential of the Gila-San Francisco Wilderness Study Area (AZ-040-022/023/024) is low (fig. 2). Although favorable geologic environments for placer gold deposits and manganese vein deposits are present in the study area, the probability of discovering economically exploitable deposits of these metals is low, and not encouraging. Even more speculative is the study area's porphyry copper potential which is based solely on the possibility of favorable host terranes underlying the study area at depth. The study area does contain substantial deposits of pumice, but their economic significance is probably minor. A part of the study area has been previously designated a Known Geothermal Resource Area (KGRA).

Environmental geochemical studies of selected mineral deposits in Wrangell-St. Elias National Park and Preserve, Alaska

USGS Publications Warehouse

Eppinger, Robert G.; Briggs, Paul H.; Rosenkrans, Danny; Ballestrazze, Vanessa

2000-01-01

Environmental geochemical investigations at Wrangell-St. Elias National Park and Preserve, Alaska, between 1994 and 1997 included studies of the Kennecott stratabound copper mines and mill area; historic mines and mill in the Bremner District, gold placer mines at Gold Hill; the undisturbed porphyry, Cu-Mo deposits at Orange Hill and Bond Creek, and the historic mines and mill at Nabesna, The study was in cooperation with the National Park Service and focused on sample media including surface water, bedload sediment, rock, mine waste, and mill tailings samples. Results demonstrate that bedrock geology and mineral deposit type must be considered when environmental geochemical effects of historic or active mine areas are evaluated.

GOAT ROCKS WILDERNESS AND ADJACENT ROADLESS AREAS, WASHINGTON.

USGS Publications Warehouse

Church, S.E.; Close, T.J.

1984-01-01

The Goat Rocks Wilderness and adjacent roadless areas are a rugged, highly forested, scenic area located on the crest of the Cascade Range in south-central Washington. Several mineral claims have been staked in the area. Mineral surveys were conducted. Geochemical, geophysical, and geologic investigations indicate that three areas have probable mineral-resource potential for base metals in porphyry-type deposits. Available data are not adequate to permit definition of the potential for oil and gas. There is little likelihood for the occurrence of other kinds of energy resources in the area. Evaluation of resource potential in the three areas identified as having probable mineral-resource potential could be improved by more detailed geochemical studies and geologic mapping.

Application of thematic mapper-type data over a porphyry-molybdenum deposit in Colorado

NASA Technical Reports Server (NTRS)

Rickman, D. L.; Sadowski, R. M.

1983-01-01

The objective of the study was to evaluate the utility of thematic mapper data as a source of geologically useful information for mountainous areas of varying vegetation density. Much of the processing was done in an a priori manner without prior ground-based information. This approach resulted in a successfull mapping of the alteration associated with the Mt. Emmons molybdenum ore body as well as several other hydrothermal systems. Supervised classification produced a vegetation map at least as accurate as the mapping done for the environmental impact statement. Principal components were used to map zones of general, subtle alteration and to separate hematitically stained rock from staining associated with hydrothermal activity. Decorrelation color composites were found to be useful field mapping aids, easily delineating many lithologies and vegetation classes of interest. The factors restricting the interpretability and computer manipulation of the data are examined.

The Impact of Soft Factors on Quality Improvement in Manufacturing Industry

NASA Astrophysics Data System (ADS)

Chan, Shiau Wei; Fauzi Ahmad, Md; Kong, Mei Wan

2017-08-01

Nowadays, soft factors have become the key factors of success in quality improvement of an organisation. Many organisations have neglected the importance of soft factors, this may influence the organisational performance. Hence, the purpose of this research is to examine the impact of soft factors on quality improvement in manufacturing industries. Six hypotheses were examined while considering six dimensions of soft factors including management commitment, customer focus, supplier relationship, employee involvement, training and education, and reward and recognition that have a positive impact on quality improvement. In this study, eighty one managers from the quality department were randomly selected in the manufacturing industry in Batu Pahat, Johor. The questionnaires were distributed to them. The researcher analysed the quantitatively collected data using descriptive analysis and correlation analysis. The findings of this study revealed that all soft factors are correlated to the quality improvement in an organisation with a high significant value but the regression analysis shows that the supplier relationship and employee involvement has more significant impact on quality improvement as compared to other soft factors which contributes of this study.

Subsurface Investigation using 2D Resistivity and Ground Penetrating Radar at Teluk Kumbar, Penang

NASA Astrophysics Data System (ADS)

Teoh, YJ; Bruka, MA; Idris, NM; Ismail, NA; Muztaza, NM

2018-04-01

The objective of this study is to determine the structure and condition of the subsurface by using 2D resistivity and Ground Penetrating Radar (GPR) methods. The study was conducted at SK Sungai Batu, Teluk Kumbar, Penang Island. For 2D resistivity method, Wenner-Schlumberger array was used while for GPR, 250 MHz antenna was used at the site. The survey consists of 200m length survey line. GPR result shows that there is high intensity of EM. 2D resistivity result shows that the low resistivity region (200 Ωm to 340 Ωm) appears to be at the centre of the survey line from depth 7 m to 13 m. Meanwhile, the higher resistivity region (4000 Ωm to 6000 Ωm) may indicate the bedrock structure of the subsurface, which is the granitic rock. This region is bedrock which rested at depth 14 m and below. In conclusion, data obtained from GPR and 2D resistivity methods can be easily correlated to determine the features of the subsurface.

Application of geophysical techniques for 3D geohazard mapping to delineate cavities and potential sinkholes in the northern part of Kuala Lumpur, Malaysia.

PubMed

Bakhshipour, Zeinab; Huat, Bujang B K; Ibrahim, Shaharin; Asadi, Afshin; Kura, Nura Umar

2013-01-01

This work describes the application of the electrical resistivity (ER) method to delineating subsurface structures and cavities in Kuala Lumpur Limestone within the Batu Cave area of Selangor Darul Ehsan, Malaysia. In all, 17 ER profiles were measured by using a Wenner electrode configuration with 2 m spacing. The field survey was accompanied by laboratory work, which involves taking resistivity measurements of rock, soil, and water samples taken from the field to obtain the formation factor. The relationship between resistivity and the formation factor and porosity for all the samples was established. The porosity values were plotted and contoured. A 2-dimensional and 3-dimensional representation of the subsurface topography of the area was prepared through use of commercial computer software. The results show the presence of cavities and sinkholes in some parts of the study area. This work could help engineers and environmental managers by providing the information necessary to produce a sustainable management plan in order to prevent catastrophic collapses of structures and other related geohazard problems.

Genetic distance estimates and variable factors distinguishing between goat Kacang, Muara and Samosir

NASA Astrophysics Data System (ADS)

Hamdan; Saputra, H.; Mirwandhono, E.; Hasnudi; Sembiring, I.; Umar, S.; Ginting, N.; Alwiyah

2018-02-01

The purpose of this research was to look the genetic distance and factors distinguishing variable betwen types of goats in North Sumatera. This research have been conducted in PayaBakung, Hamparan Perak and Klambir Lima village, Deli Serdang district, Batu Binumbun, Aritonang, HutaGinjang village, Muarasubdistrict, North Tapanuli district and ParbabaDolok, Siopat Sosor, Sinabulan village, Ronggur Nihuta Pangururan village, Sitonggi-tonggi village in the subdistrict RonggurNihuta, Samosir district of the month of July 2016. The data was analyzed using descriptive, discriminants, canonical, Principal Component Analysis, Distance genetic and Tree Phylogenetic. The result showed that the nearest genetic distance goat found in Kacang and Samosir (1.973), and the farthest genetic distnace find in Samosir and Muara (8.671). The variables made it difference was goat race Base Rim Horn (0.856) and Long Horn (0.878). Genetic distance values most far between Muaragoat with Samosir goat was (8.671). The conclude that the crossing superior result, must be cross between two goat types with value genetics most distance. It will have a better chance heterosis in cross result.

BBIS: Beacon Bus Information System

NASA Astrophysics Data System (ADS)

Kasim, Shahreen; Hafit, Hanayanti; Pei Juin, Kong; Afizah Afif, Zehan; Hashim, Rathiah; Ruslai, Husni; Jahidin, Kamaruzzaman; Syafwan Arshad, Mohammad

2016-11-01

Lack of bus information for example bus timetable, status of the bus and messy advertisement on bulletin board at the bus stop will give negative impact to tourist. Therefore, a real-time update bus information bulletin board provides all information needed so that passengers can save their bus information searching time. Supported with Android or iOS, Beacon Bus Information System (BBIS) provides bus information between Batu Pahat and Kluang area. BBIS is a system that implements physical web technology and interaction on demand. It built on Backend-as-a-Service, a cloud solution and Firebase non relational database as data persistence backend and syncs between user client in the real-time. People walk through bus stop with smart device and do not require any application. Bluetooth Beacon is used to achieve smart device's best performance of data sharing. Intellij IDEA 15 is one of the tools that that used to develop the BBIS system. Multi-language included front end and backend supported Integration development environment (IDE) helped to speed up integration process.

Application of Geophysical Techniques for 3D Geohazard Mapping to Delineate Cavities and Potential Sinkholes in the Northern Part of Kuala Lumpur, Malaysia

PubMed Central

Bakhshipour, Zeinab; Huat, Bujang B. K.; Ibrahim, Shaharin; Asadi, Afshin

2013-01-01

This work describes the application of the electrical resistivity (ER) method to delineating subsurface structures and cavities in Kuala Lumpur Limestone within the Batu Cave area of Selangor Darul Ehsan, Malaysia. In all, 17 ER profiles were measured by using a Wenner electrode configuration with 2 m spacing. The field survey was accompanied by laboratory work, which involves taking resistivity measurements of rock, soil, and water samples taken from the field to obtain the formation factor. The relationship between resistivity and the formation factor and porosity for all the samples was established. The porosity values were plotted and contoured. A 2-dimensional and 3-dimensional representation of the subsurface topography of the area was prepared through use of commercial computer software. The results show the presence of cavities and sinkholes in some parts of the study area. This work could help engineers and environmental managers by providing the information necessary to produce a sustainable management plan in order to prevent catastrophic collapses of structures and other related geohazard problems. PMID:24501583

Geology of the Jabal Riah area, Kingdom of Saudi Arabia

USGS Publications Warehouse

Wells, J.D.

1982-01-01

The Jabal Riah area is in the southern part of the Jibal al Hamdah quadrangle (lat 19?00'00'' to 19?07'S0'' N., long 45?37'30'' to 43?45'00' E.) in the southeastern Precambrian Shield, Asir Province, Kingdom of Saudi Arabia. The Jabal Mahanid group of ancient gold mines, which is part of the Jabal Ishmas-Wadi Tathlith gold belt, is in the west-central part of the area. Rocks in the Jabal Riah area consist of Precambrian layered metasedimentary and metavolcanic rocks intruded by Precambrian igneous rocks. The metamorphic rocks are, from oldest to youngest, interlayered hornblende and biotite schist, quartz-biotite schist, hornblende schist, serpentinite, and chlorite schist. The igneous rocks are, from oldest to youngest, diorite-gabbro including dikes, granodiorite, monzogranite-granodiorite, leucocratic quartz porphyry, rhyolite, and aplite and pegmatite dikes. A large area of jasper replaces serpentinite. On the valley floors, recent alluvium and pediment deposits overlie the bedrock. The structure of the area is dominated by a dome centered over the eastern border of the area; leucocratic quartz porphyry forms the core of the dome. Minor folds and faults are present. The Jabal Mahanid group of ancient gold mines is on a northwest-trending vein system, and major ancient mine areas are found where the system splits or changes direction. The veins consist of zones of brecciated and crushed rock, which are generally less than 0.5 m wide but may be as wide as 1 m. These zones contain quartz and calcite stringers and commonly are along hornblende schist-serpentinite contacts; however, they also cut both units. Most aplite, pegmatite, and quartz dikes in the area are thin and discontinuous and are intruded along the vein trend. Similar veins, at the same stratigraphic interval, have been found beyond the northeastern part of the map area. The veins contain detectable gold and silver (median gold, approximately 0.14 ppm; median silver, approximately 1 ppm). Gold and

Multiple Sulfate Isotopic Evidence on the Formation of Oxide Copper Ore at Spence, Atacama Desert, Northern Chile

NASA Astrophysics Data System (ADS)

Sun, T.; Bao, H.; Reich, M.; Palacios, C.

2007-12-01

In the Atacama Desert of northern Chile, one of the world's richest metallogenic provinces, porphyry copper deposits are characterized by the unique occurrence of atacamite in their oxidized zones. The origin and formation of the oxide zone of these copper deposits is, however, controversial. It was proposed that Cl-rich deep formation water pumping-up events along faults by earthquakes, after onset of the hyperaridity, were required (Cameron et al., 2007). Their model would imply that supplies of saline deep formation water from fractures to the surface should have left behind a homogeneous or fracture-controlled salt profile from surface down to the oxide zone. While no excluding the deep formation water model in other deposit, here we propose that, in our sampling region, the alternative saline source, which is critical for atacamite formation, could be locally evaporated groundwater, Cl-rich salts leached from arid surface by meteoric water, or brines from eastern salar basins at a time when the climate in northern Chile was changing from arid to hyperarid. At this climate transition, arid- requiring minerals such as atacamite in the oxide zone were formed and, more importantly, preserved upon evaporation beneath the surface alluvial deposits. Since salt accumulation at the surface remain active during hyperarid condition, our model would predict that water-soluble salt profile from surface to the oxide zone should have a characteristic pattern: salts with an atmospheric component on the surface gradually transitioning to salts of the oxide ore zone on the bottom and a mixing zone in between. To test these two alternative models, we focus on sulfate salts, one of the common water-soluble salts in arid environments. An added advantage is that sulfate accumulated on desert surface has a secondary atmospheric component that bears a unique triple oxygen isotope signature, easily distinguishable from sulfate formed by the oxidation of sulfide minerals at the oxide