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Reimar Seltmann - One of the best experts on this subject based on the ideXlab platform.
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the mesoproterozoic abra polymetallic sedimentary rock hosted Mineral Deposit edmund basin western australia
Ore Geology Reviews, 2016Co-Authors: Franco Pirajno, Terrence P Mernagh, David L Huston, Robert A Creaser, Reimar SeltmannAbstract:Abstract Abra is a blind, sedimentary rock-hosted polymetallic Fe–Pb–Zn–Ba–Cu ± Au ± Ag ± Bi ± W Deposit, discovered in 1981, located within the easterly trending Jillawarra rift sub-basin of the Mesoproterozoic Edmund Basin, Capricorn Orogen, Western Australia. The Edmund Basin contains a 4–10 km thick succession of siltstone, sandstone, dolomitic siltstone, and stromatolitic dolomite. The age of the Edmund Group is between 1.66 and 1.46 Ga. The Abra polymetallic Deposit is hosted in siltstone, dolostone, sandstone and conglomerate of the Irregully and Kiangi Creek Formations, but the Mineralised zones do not extend above an erosion surface marking the change from fluvial to marine facies in the lower part of the Kiangi Creek Formation. The Abra Deposit is characterised by a funnel-shaped brecciated zone, interpreted as a feeder pipe, overlain by stratiform–stratabound Mineralisation. The stratiform–stratabound Mineralisation includes a Red Zone and an underlying Black Zone. The Red Zone is characterised by banded jaspilite, hematite, galena, pyrite, quartz, barite, and siderite. The jaspilite and hematite cause the predominant red colouration. The Black Zone consists of veins and rhythmically banded sulphides, laminated and/or brecciated hematite, magnetite, Fe-rich carbonate and scheelite. In both zones, laminations and bands of sulphide Minerals, Fe oxides, barite and quartz commonly exhibit colloform textures. The feeder pipe (Stringer Zone) merges with Black Zone and consists of a stockwork of Fe-carbonate-quartz, barite, pyrite, magnetite and chalcopyrite, exhibiting fluidised and/or jigsaw textures. The Abra Mineral system is characterised by several overprinting phases of hydrothermal activity, from several stages of brecciation and fluidisation, barite and sulphide veining to barren low-temperature chalcedonic (epithermal regime) veining. Hydrothermal alteration Minerals include multi-stage quartz, chlorite, prehnite, Fe-rich carbonate and albite. Albite (Na metasomatism) is an early alteration phase, whereas Fe-rich carbonate is a late phase. Fluid inclusion studies indicate that the ore fluids had temperatures ranging from 162 to 250 °C, with salinities ranging from 5.8 to about 20 wt.% NaCl. In the course of our studies, microthermometric and Raman microprobe analyses were performed on fluid inclusions in carbonate, quartz and barite grains. Fluid inclusions in quartz show homogenisation temperatures ranging from 150 to 170 °C with calculated salinities of between 3.7 and 13.8 wt.% NaCl. The sulphur isotopic system shows δ 34 S values ranging from 19.4 to 26.6‰ for sulphides and from 37.4 to 41.9‰ for barite ( Vogt and Stumpfl, 1987; Austen, 2007 ). Sulphur isotope thermometry between sulphides and sulphide–barite pairs yields values ranging from 219 to 336 °C ( Austen, 2007 ). Galena samples were analysed for Pb isotope ratios, which have been compared with previous Pb isotopic data. The new Pb isotope systematics show model ages of 1650–1628 Ma, consistent with the formation of the host Edmund Basin. Re–Os dating of euhedral pyrite from the Black Zone yielded an age of ~ 1255 Ma. This age corresponds to the 1320–1170 Ma Mutherbukin tectonic event in the Gascoyne Complex. This event is manifested primarily along a WNW-trending structural corridor of amphibolite facies rocks, about 250 km to the northwest of the Abra area. It is possible that the Re–Os age represents a younger re-activation event of an earlier SEDEX style system with a possible age range of 1640–1590 Ma. A genetic model for Abra is proposed based on the above data. The model involves two end-members ore-forming stages: the first is the formation of the SEDEX style Mineral systems, followed by a second multi-phase stage during which there was repeated re-working of the Mineral system, guided by seismic activity along major regional faults.
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GIS package on Mineral Deposits database and thematic maps of Central Eurasia
Mineral Deposit Research: Meeting the Global Challenge, 2005Co-Authors: Reimar Seltmann, V. Shatov, G. Guriev, A. Yakubchuk, Alla DolgopolovaAbstract:The GIS (Geographic Information System) Central Asia is composed of spatially referenced geographical, geological, geophysical, geochemical and Mineral Deposit thematic layers, and their respective attribute data. It is issued to establish insights in the regions Mineral potential and its past and future mining activities. Subsequently, the information system is further exploited to derive new rules between the different attribute information in their relation to Mineral Deposit information and the special distribution of the Deposits.
K.e. Venance - One of the best experts on this subject based on the ideXlab platform.
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Trace element mobility in mine waters from granitic pegmatite U–Th–REE Deposits, Bancroft area, Ontario
Applied Geochemistry, 2016Co-Authors: Alexandre J. Desbarats, Jeanne B. Percival, K.e. VenanceAbstract:Abstract Small, low-grade, granitic pegmatite U–Th–REE Deposits are found throughout the Grenville geological province of eastern Canada. Groundwater quality at historical mining properties in the Bancroft area was investigated in order to better understand the mobility of trace elements that may pose health risks if there is renewed development of this class of Mineral Deposit. Groundwater samples were obtained from diamond drill holes, flowing adits and flooded mine shafts. Uranium occurs almost entirely in the dissolved (
Vladimi A Lisitsi - One of the best experts on this subject based on the ideXlab platform.
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spatial data analysis of Mineral Deposit point patterns applications to exploration targeting
Ore Geology Reviews, 2015Co-Authors: Vladimi A LisitsiAbstract:Abstract Systematic spatial analysis of Mineral Deposit point patterns can reveal significant spatial properties of Mineral systems, with major implications for regional Mineral prospectivity modelling. For valid results, a study area needs to be clearly defined, taking into account permissiveness of the geological units for a particular Mineral system and effects of cover. Standard statistical tests assuming an isometric contiguous study area with regionally homogeneous distribution of Deposits are likely to produce invalid results. Analysis of regional uniformity of spatial Deposit density is required for adequate design and interpretation of tests for clustering. Spatial distribution of orogenic gold Deposits in the Hodgkinson Province in Queensland and the Western Lachlan Orogen in Victoria (Australia) indicates the presence of significant regional linear metallogenic zones, probably controlled by deep crustal domain boundaries oblique and not related to any recognised major faults. Within the metallogenic zones in both regions, individual gold occurrences are strongly clustered into ore fields, but the distribution of ore fields is random.
Alexandre J. Desbarats - One of the best experts on this subject based on the ideXlab platform.
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Trace element mobility in mine waters from granitic pegmatite U–Th–REE Deposits, Bancroft area, Ontario
Applied Geochemistry, 2016Co-Authors: Alexandre J. Desbarats, Jeanne B. Percival, K.e. VenanceAbstract:Abstract Small, low-grade, granitic pegmatite U–Th–REE Deposits are found throughout the Grenville geological province of eastern Canada. Groundwater quality at historical mining properties in the Bancroft area was investigated in order to better understand the mobility of trace elements that may pose health risks if there is renewed development of this class of Mineral Deposit. Groundwater samples were obtained from diamond drill holes, flowing adits and flooded mine shafts. Uranium occurs almost entirely in the dissolved (
Georges Beaudoin - One of the best experts on this subject based on the ideXlab platform.
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Discriminant diagrams for iron oxide trace element fingerprinting of Mineral Deposit types
Mineralium Deposita, 2011Co-Authors: Céline Dupuis, Georges BeaudoinAbstract:Magnetite and hematite are common Minerals in a range of Mineral Deposit types. These Minerals form partial to complete solid solutions with magnetite, chromite, and spinel series, and ulvospinel as a result of divalent, trivalent, and tetravalent cation substitutions. Electron microprobe analyses of minor and trace elements in magnetite and hematite from a range of Mineral Deposit types (iron oxide-copper-gold (IOCG), Kiruna apatite–magnetite, banded iron formation (BIF), porphyry Cu, Fe-Cu skarn, Fe-Ti, V, Cr, Ni-Cu-PGE, Cu-Zn-Pb volcanogenic massive sulfide (VMS) and Archean Au-Cu porphyry and Opemiska Cu veins) show compositional differences that can be related to Deposit types, and are used to construct discriminant diagrams that separate different styles of Mineralization. The Ni + Cr vs. Si + Mg diagram can be used to isolate Ni-Cu-PGE, and Cr Deposits from other Deposit types. Similarly, the Al/(Zn + Ca) vs. Cu/(Si + Ca) diagram can be used to separate Cu-Zn-Pb VMS Deposits from other Deposit types. Samples plotting outside the Ni-Cu-PGE and Cu-Zn-Pb VMS fields are discriminated using the Ni/(Cr + Mn) vs. Ti + V or Ca + Al + Mn vs. Ti + V diagrams that discriminate for IOCG, Kiruna, porphyry Cu, BIF, skarn, Fe-Ti, and V Deposits.