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Mine Area (mine + area)

Distribution by Scientific Domains
Earth and Environmental Science75%

Selected Abstracts

The possible hydrologic effects of the proposed lignite open-cast mining in Drama lignite field, Greece

HYDROLOGICAL PROCESSES, Issue 11 2008
Sotiris Panilas
Abstract The present study investigates the possible hydrologic effects of the proposed lignite open-cast mining in Drama lignite field (north Greece). Recent years have seen a rapid increase in surface mining. This activity has generated a growing concern for the potential environmental impacts associated with large scale surface mining. In order to achieve a safe mine operation and allow extraction of lignite to considerable depths, extensive dewatering by pumping will be necessary, while at the same time it is desirable to avoid presence of overpumping conditions in the broader area. Based on stratigrafic, hydrologic and hydrogeologic data, a three-dimensional finite difference model was developed in order to simulate the dewatering process of the western part of the lignite open-cast mine in Drama and to predict both spatially and temporally the decline of ground water level down to the lignite surface. The dewatering of the part of the aquifer which underlies the mine area will influence the hydrological conditions of the broader region. The most important anticipated effects will be the abandonment of shallow wells as well as the decrease of ground water pumping rates of deep wells. Aquifer discharge towards the ditches of the study area will cease and there will be an inversion of ground water flow from the ditches towards the underlying aquifer. Dewatering activities will probably result in minor subsidence of the nearby peat deposits of Drama Philippi marshes. Moreover, sand pumping as well as the presence of gasses is likely to cause local subsidence phenomena, mainly in the pit slopes. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Yerranderie a Late Devonian Silver,Gold,Lead Intermediate Sulfidation Epithermal District, Eastern Lachlan Orogen, New South Wales, Australia

RESOURCE GEOLOGY, Issue 1 2007
Peter M. Downes
Abstract Felsic volcanic units of the Early Devonian Bindook Volcanic Complex host the Yerranderie epithermal silver,gold,lead district 94 km west,southwest of Sydney. Mineralization in the district forms part of a fault-controlled, intermediate sulfidation, epithermal silver,gold,base metal vein system that has significant mineral and alteration zonation. Stage 1 of the mineral paragenesis in the veins developed quartz and carbonate with early pyrite, whereas stage 2 is a crustiform banded quartz,pyrite,arsenopyrite assemblage. Stage 3, the main stage of sulfide deposition, comprises early sphalerite, followed by a tetrahedrite,tennantite,gold assemblage, then a galena,chalcopyrite,native silver,pyrite assemblage, and finally a pyrargyrite,polybasite,pearceite assemblage. Stage 4 involves the deposition of quartz veins with minor (late) pyrite and stage 5 is characterized by siderite that infilled remaining voids. Mineral zonation occurs along the Yerranderie Fault, with bornite being restricted to the Colon Peaks,Silver Peak mine area, whereas arsenopyrite, which is present in both the Colon Peaks,Silver Peak and Wollondilly mine areas, is absent in other lodes along the Yerranderie Fault. The Yerranderie Fault, which hosts the major lodes, is surrounded by a zoned alteration system. With increasing proximity to the fault the intensity of alteration increases and the alteration assemblage changes from an outer quartz,muscovite,illite,(ankerite) assemblage to a quartz,illite,(pyrite,carbonate) assemblage within meters of the fault. 40Ar/39Ar dating of muscovite from the alteration zone gave a 372.1 ± 1.9 Ma (Late Devonian) age, which is interpreted to be the timing of the quartz,sulfide vein formation. Sulfur isotope values for sulfides range from 0.1 to 6.2, with one outlier of ,5.6 ,34S,. The results indicate that the initial ore-forming fluids were reduced, and that sulfur was probably sourced from a magmatic reservoir, either as a direct magmatic contribution or indirectly through dissolution and recycling of sulfur from the host volcanic sequence. The sulfur isotope data suggest the system is isotopically zoned. [source]

Acid Mine Drainage and Heavy Metal Pollution from Solid Waste in the Tongling Mines, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2008
XU Xiaochun
Abstract: Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the differences of acid mine drainage (AMD) of the tailings and the waste rocks are discussed, and the modes of occurrence of heavy metal elements in the mine solid waste are also studied. The Fenghuangshan copper mine hardly produces AMD, whereas the Xinqiao pyrite mine does and there are also differences in the modes of occurrence of heavy metal elements in the tailings. For the former, toxic heavy metals such as Cu, Pb, Zn, Cd, As and Hg exist mostly in the slag mode, as compared to the latter, where the deoxidization mode has a much higher content, indicating that large amounts minerals in the waste rocks have begun to oxidize at the earth surface. AMD is proved to promote the migration and spread of the heavy metals in mining waste rocks and lead to environmental pollution of the surroundings of the mine area. [source]

Yerranderie a Late Devonian Silver,Gold,Lead Intermediate Sulfidation Epithermal District, Eastern Lachlan Orogen, New South Wales, Australia

RESOURCE GEOLOGY, Issue 1 2007
Peter M. Downes
Abstract Felsic volcanic units of the Early Devonian Bindook Volcanic Complex host the Yerranderie epithermal silver,gold,lead district 94 km west,southwest of Sydney. Mineralization in the district forms part of a fault-controlled, intermediate sulfidation, epithermal silver,gold,base metal vein system that has significant mineral and alteration zonation. Stage 1 of the mineral paragenesis in the veins developed quartz and carbonate with early pyrite, whereas stage 2 is a crustiform banded quartz,pyrite,arsenopyrite assemblage. Stage 3, the main stage of sulfide deposition, comprises early sphalerite, followed by a tetrahedrite,tennantite,gold assemblage, then a galena,chalcopyrite,native silver,pyrite assemblage, and finally a pyrargyrite,polybasite,pearceite assemblage. Stage 4 involves the deposition of quartz veins with minor (late) pyrite and stage 5 is characterized by siderite that infilled remaining voids. Mineral zonation occurs along the Yerranderie Fault, with bornite being restricted to the Colon Peaks,Silver Peak mine area, whereas arsenopyrite, which is present in both the Colon Peaks,Silver Peak and Wollondilly mine areas, is absent in other lodes along the Yerranderie Fault. The Yerranderie Fault, which hosts the major lodes, is surrounded by a zoned alteration system. With increasing proximity to the fault the intensity of alteration increases and the alteration assemblage changes from an outer quartz,muscovite,illite,(ankerite) assemblage to a quartz,illite,(pyrite,carbonate) assemblage within meters of the fault. 40Ar/39Ar dating of muscovite from the alteration zone gave a 372.1 ± 1.9 Ma (Late Devonian) age, which is interpreted to be the timing of the quartz,sulfide vein formation. Sulfur isotope values for sulfides range from 0.1 to 6.2, with one outlier of ,5.6 ,34S,. The results indicate that the initial ore-forming fluids were reduced, and that sulfur was probably sourced from a magmatic reservoir, either as a direct magmatic contribution or indirectly through dissolution and recycling of sulfur from the host volcanic sequence. The sulfur isotope data suggest the system is isotopically zoned. [source]