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A new type of gold mineralisation containing minor amounts of platinum and palladium has been found proximal to the secondary redox interface located below the Cu-Ag Kupferschiefer orebody of the Polkowice-Sieroszowice mine in the south-western part of the Lubin-Sieroszowice district, Poland. This deposit can be classified as redbed-type gold. Our study shows that gold, platinum and palladium occur in secondary red-coloured sections of the basal Zechstein sedimentary rocks and in the uppermost Weissliegendes sandstone. Noble metal mineralisation occurs within an average interval of 0.22 m, which lies directly below the copper ores. The average grade of the horizon is 2.25 ppm Au, 0.138 ppm Pt and 0.082 ppm Pd with a metal content of several tens of tonnes of gold. A transition zone has been recognised between the gold-bearing horizon and the copper deposit. This transition zone is characterised by the presence of low grades of copper (<0.2 wt%) and elevated gold contents (>0.5 ppm). Native gold accompanied by electrum, mercury-bearing gold, haematite, covellite, chalcocite, bornite and chalcopyrite has been identified in the gold-bearing horizon. In some sections, Pd-arsenides, tetra-auricupride, Co-arsenides, clausthalite, tennantite, digenite, yarrowite, spionkopite and galena have also been noted. 相似文献
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Dinh Chau Nguyen Phon Le Khanh Paweł Jodłowski Jadwiga Pieczonka Adam Piestrzyński Hao Duong Van Jakub Nowak 《Acta Geophysica》2016,64(6):2305-2321
The field radiometric and laboratory measurements were performed at the Sin Quyen copper deposit in North Vietnam. The field gamma-ray spectrometry indicated the concentration of uranium ranging from 5.5 to 87 ppm, thorium from 5.6 to 33.2 ppm, and potassium from 0.3 to 4.7%. The measured dose rates ranged from 115 to 582 nGy/h, the highest doses being at the copper ore. Concentrations in the solid samples were in the range of 20–1700 Bq/kg for uranium, 20–92.7 Bq/kg for thorium, and 7–1345 Bq/kg for potassium. The calculated doses were from 22 to 896 nGy/h; both measured and calculated dose rates are mostly related to uranium. Concentrations of radium in water samples were below 0.17 Bq/L. Uranium in water samples was significantly higher than the hydrogeological background; the maximum of 13 Bq/L was at the waste zone pool, but neither radium nor uranium were present in tap water. Radon concentration in the dwelling air was from 42 to 278 Bq/m3 for 222Rn and from 8 to 193 Bq/m3 for 220Rn. The estimated committed dose rates were principally related to 222Rn concentration and ranged from 1.1 to 8.1 mSv/y. 相似文献
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Tino Pieczonka Tobias Bolch Manfred Buchroithner 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(6):927-940
Multitemporal digital terrain models (DTM) are an important source for many purposes such as the detection of areas, which are susceptible to natural hazards such as landslides and glacial lake outburst floods, or for the examination of changes in glacier thickness. To exploit the potential of stereo satellite and aerial imagery for time series analysis, the employed methodology and software can be critical. A statistical analysis based on quartiles is presented to eliminate the influence of registration and elevation errors in DTMs. For our analysis, we used multi-temporal airborne and spaceborne stereoscopic images. The oldest images were recorded in the 1960s by the US American reconnaissance satellite Corona, while the most recent imagery are 2007 Cartosat-1 stereo scenes, along with one ASTER stereo pair. Complex panoramic distortion and limited spatial resolution resulted in the Corona and ASTER DTMs having the highest RMSEz. Due to differing acquisition techniques, applied software packages and temporal differences DTMs will never be identical. Therefore, we propose a relative vertical accuracy assessment with a master DTM. We chose the Cartosat-1 DTM as it showed the highest absolute accuracy. Inaccuracies between the master and the slave DTMs were adjusted by means of trend surfaces and outliers were successfully eliminated applying the interquartile range. 相似文献
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Bo Peng Adam Piestrzynski Jadwiga Pieczonka Meilian Xiao Yaozhu Wang Shurong Xie Xiaoyan Tang Changxun Yu Zhi Song 《Environmental Geology》2007,52(7):1277-1296
The mineralogy and geochemistry of the waste rocks distributed at Taojiang Mn-ore deposit, central Hunan province, China,
were studied using X-ray powder diffraction (XRD), electron microprobe analysis (EMPA) fitted with energy dispersive spectrometer
(EDS) and inductively coupled plasma mass spectrum (atomic emission spectra) ICP-MS (AES), with the aim of predicting the
environmental impacts of weathering of the waste rocks. The mineralogical results from microscope observation and XRD and
EMPA studies show that the waste rock is composed of black shale and minor Mn carbonates. The oxidation of sulfide minerals
such as galena, pyrite and chalcopyrite is accompanied by decomposition of Mn carbonates and K-feldspar during exposure to
atmospheric O2. The geochemical characteristics of major, rare earth elements (REE) and trace elements of the waste rocks also show that
the waste rock can be divided into black shale and Mn carbonate, and both of them are currently under chemical weathering.
The major alkalies and alkaline elements (Ca, Mg, Na, K, Rb, Sr and Cs) and major elements (Fe, S and P) and heavy metals
(Sc, V, Cr, Th, U, Sn, Co, Ni, Cu, Zn, Pb, Mo, Cd, Sb, an Tl) are being released during weathering. The mobility of alkalis
and alkaline elements Ca, Mg, Na, K, Rb, Sr and Cs is controlled by decomposition of Mn carbonates. The dispersion of Cr,
Sc and Th (U) might be related to weathering of K-feldspar, and the release of the heavy metals Co, Ni, Cu, Zn, Pb, Mo, Cd
Sb and Tl is dominated by the breaking of sulfide minerals. The REE of the waste rocks and surrounding soils and the spidery
distribution patterns of heavy metals in the waste rocks, the surrounding soils and the surface waters show that weathering
of the waste rocks and bedrock might be the sources of heavy metal contamination for the surrounding soils and surface water
system for the mining area. This is predicted by the mass-balance calculation by using Zr as an immobile element. Therefore,
it is urgently necessary take measures to treat the waste rocks distributed throughout the area for the local environmental
protection. 相似文献
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Underground prospecting within the Lubin-Sieroszowice mining area which took place during last 5 years,led to a discovery of a new type of Au,Pt and Pd mineralisation located0-0.5 m below the copper-silver orebody in the south-western part of the Polish Permian Basin.The gold-bearing zone lies mainly in the Weissliegendes sandstone (Iower Permian),but locally transgresses the stratigraphic sequence into the overlying kupferschiefer and Werra limestone (Zechstein). 相似文献
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