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Ajouter le résultat dans votre panierFormation and evolution of the centennial unconformity-related uranium deposit in the south-central Athabasca basin, Canada / P. Alexandre in Economic geology, Vol. 107 N° 3 (Mai 2012)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 385-400
Titre : Formation and evolution of the centennial unconformity-related uranium deposit in the south-central Athabasca basin, Canada Type de document : texte imprimé Auteurs : P. Alexandre, Auteur ; K. Kyser, Auteur ; D. Jiricka, Auteur Année de publication : 2012 Article en page(s) : pp. 385-400 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Uranium deposit Athabasca basin Canada Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Centennial U deposit is situated in the south-central Athabasca Basin (Canada) and straddles the unconformity between early Paleoproterozoic to Archean metasedimentary and metavolcanic rocks and granitoids, and the clastic sediments of the Paleoproterozoic Athabasca Group. Although it has most characteristics of an unconformity-related uranium deposit, the Centennial deposit is atypical in that it is not directly associated with an electromagnetic conductor (there is a paucity of graphite in the basement) or with a major reverse fault zone; it is distal from a major fluid conduit (ca. 300 to 400 m from the Dufferin Lake Fault), has low Ni, Cu, Co, Zn, and Pb contents, and contains an unusually large amount (up to 5%) of secondary uranyl minerals. Additionally, a network of diabase dikes and sills is observed at Centennial, seemingly intruding the main U mineralization of massive uraninite, based on the relatively sharp contacts between the diabase dike and the high-grade U mineralization.
The pre-U alteration assemblage at Centennial includes kaolinite, illite, and sudoite, which have been formed by fluids with isotopic and chemical compositions that are comparable with those from other sandstone-hosted unconformity-type U deposits in the Athabasca Basin. Pre-U illite-related fluids have δ18O of ca. 3‰ and δD of ca. −40‰, whereas pre-U chlorite-related fluids have δ18O between 1.7 and 4.3‰ and δD between −18 and 1‰.
Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U/Pb dating of the various U phases indicates that initial mineralization, represented by disseminated uraninite found directly to the north-northeast of the Centennial deposit, occurred at ca. 1.6 Ga. The main U mineralization, represented by massive and strongly altered uraninite, followed at an unknown time. A minor (<5%) unaltered uraninite formed from the local remobilization of the main massive uraninite at ca. 380 Ma. The main uranyl mineral, uranophane, formed last, at ca. 2 Ma. The recurrence of local U remobilization might have been facilitated by the persisting high permeability of the sandstones in the area due to the nearby Dufferin Lake Fault and to the emplacement of the diabase dikes.
The usefulness of Pb isotopes for exploration is demonstrated at the Centennial deposit, with strongly radiogenic Pb isotope signatures close to the deposit and a common Pb signature observed at a distance of a few km from the deposit.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/385.abstract [article] Formation and evolution of the centennial unconformity-related uranium deposit in the south-central Athabasca basin, Canada [texte imprimé] / P. Alexandre, Auteur ; K. Kyser, Auteur ; D. Jiricka, Auteur . - 2012 . - pp. 385-400.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 385-400
Mots-clés : Uranium deposit Athabasca basin Canada Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Centennial U deposit is situated in the south-central Athabasca Basin (Canada) and straddles the unconformity between early Paleoproterozoic to Archean metasedimentary and metavolcanic rocks and granitoids, and the clastic sediments of the Paleoproterozoic Athabasca Group. Although it has most characteristics of an unconformity-related uranium deposit, the Centennial deposit is atypical in that it is not directly associated with an electromagnetic conductor (there is a paucity of graphite in the basement) or with a major reverse fault zone; it is distal from a major fluid conduit (ca. 300 to 400 m from the Dufferin Lake Fault), has low Ni, Cu, Co, Zn, and Pb contents, and contains an unusually large amount (up to 5%) of secondary uranyl minerals. Additionally, a network of diabase dikes and sills is observed at Centennial, seemingly intruding the main U mineralization of massive uraninite, based on the relatively sharp contacts between the diabase dike and the high-grade U mineralization.
The pre-U alteration assemblage at Centennial includes kaolinite, illite, and sudoite, which have been formed by fluids with isotopic and chemical compositions that are comparable with those from other sandstone-hosted unconformity-type U deposits in the Athabasca Basin. Pre-U illite-related fluids have δ18O of ca. 3‰ and δD of ca. −40‰, whereas pre-U chlorite-related fluids have δ18O between 1.7 and 4.3‰ and δD between −18 and 1‰.
Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U/Pb dating of the various U phases indicates that initial mineralization, represented by disseminated uraninite found directly to the north-northeast of the Centennial deposit, occurred at ca. 1.6 Ga. The main U mineralization, represented by massive and strongly altered uraninite, followed at an unknown time. A minor (<5%) unaltered uraninite formed from the local remobilization of the main massive uraninite at ca. 380 Ma. The main uranyl mineral, uranophane, formed last, at ca. 2 Ma. The recurrence of local U remobilization might have been facilitated by the persisting high permeability of the sandstones in the area due to the nearby Dufferin Lake Fault and to the emplacement of the diabase dikes.
The usefulness of Pb isotopes for exploration is demonstrated at the Centennial deposit, with strongly radiogenic Pb isotope signatures close to the deposit and a common Pb signature observed at a distance of a few km from the deposit.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/385.abstract
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 401-425
Titre : Basin evolution and unconformity-related uranium mineralization : the Camie river U prospect, paleoproterozoic Otish basin, Quebec Type de document : texte imprimé Auteurs : S. R. Beyer, Auteur ; K. Kyser, Auteur ; E. E. Hiatt, Auteur Année de publication : 2012 Article en page(s) : pp. 401-425 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Paleoproterozoic Otish basin Uranium deposits Camie river uranium prospects Quebec Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Paleoproterozoic Otish Basin, Quebec, hosts several uranium prospects that until recently remained underexplored and poorly understood. In this study, the Camie River U prospect, which shows similar characteristics to high-grade unconformity-related U deposits, is the focus of an integrated basin analysis in the western Otish Basin.
Conglomerate and sandstone of the Indicator Formation, which were deposited in at least six depositional sequences, were affected by insignificant early diagenetic compaction and cementation. This allowed the formation of regional peak diagenetic aquifers, which became muscovite altered due to interaction with fluids having δ18O and δ2H values similar to those of seawater-influenced basinal brines at 250°C.
U mineralization at Camie River occurred at 1721 ±20 Ma based on a 207Pb/206Pb date obtained by laser ablation of uraninite, which coincides with a phase of the Otish Gabbro intrusion that has been dated at ca. 1730 Ma. The intrusive event promoted circulation of U-bearing basinal brines, triggering U mineralization at several locations in the western Otish Basin. Interaction of basinal brines with the Otish Gabbro produced coarse-grained chlorite, tourmaline, and phengitic muscovite, which decreased the fluid-conducting capabilities of diagenetic aquifers and resulted in fault zone- and fracture-dominated fluid flow.
Subsequent fluid alteration events produced limited U remobilization, sulfides, sudoite, and siderite between ca. 1670 and 1410 Ma based on mineral paragenesis and 40Ar/39Ar dates of muscovite. Metamorphic fluids having high δ18O values and temperatures around 300°C accompanied 1.2 to 1.0 Ga Grenville orogenesis and subgreenschist-grade metamorphism in the Otish Basin but were present at low water/rock ratios at Camie River and therefore produced little alteration. Post-Grenville uplift of the Otish Basin likely produced late, low-temperature alteration minerals that have been influenced by recent meteoric water, suggesting that the fault zones and fractures the minerals occupy remain as preferential fluid-flow pathways to the present day.
Radiogenic Pb and the characteristic trace elements Mo + W + Nb have also preferentially dispersed from the mineralization along fault zones, fractures, and depositional sequence boundaries, and can be used to explore for Camie River-style U mineralization.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/401.short [article] Basin evolution and unconformity-related uranium mineralization : the Camie river U prospect, paleoproterozoic Otish basin, Quebec [texte imprimé] / S. R. Beyer, Auteur ; K. Kyser, Auteur ; E. E. Hiatt, Auteur . - 2012 . - pp. 401-425.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 401-425
Mots-clés : Paleoproterozoic Otish basin Uranium deposits Camie river uranium prospects Quebec Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Paleoproterozoic Otish Basin, Quebec, hosts several uranium prospects that until recently remained underexplored and poorly understood. In this study, the Camie River U prospect, which shows similar characteristics to high-grade unconformity-related U deposits, is the focus of an integrated basin analysis in the western Otish Basin.
Conglomerate and sandstone of the Indicator Formation, which were deposited in at least six depositional sequences, were affected by insignificant early diagenetic compaction and cementation. This allowed the formation of regional peak diagenetic aquifers, which became muscovite altered due to interaction with fluids having δ18O and δ2H values similar to those of seawater-influenced basinal brines at 250°C.
U mineralization at Camie River occurred at 1721 ±20 Ma based on a 207Pb/206Pb date obtained by laser ablation of uraninite, which coincides with a phase of the Otish Gabbro intrusion that has been dated at ca. 1730 Ma. The intrusive event promoted circulation of U-bearing basinal brines, triggering U mineralization at several locations in the western Otish Basin. Interaction of basinal brines with the Otish Gabbro produced coarse-grained chlorite, tourmaline, and phengitic muscovite, which decreased the fluid-conducting capabilities of diagenetic aquifers and resulted in fault zone- and fracture-dominated fluid flow.
Subsequent fluid alteration events produced limited U remobilization, sulfides, sudoite, and siderite between ca. 1670 and 1410 Ma based on mineral paragenesis and 40Ar/39Ar dates of muscovite. Metamorphic fluids having high δ18O values and temperatures around 300°C accompanied 1.2 to 1.0 Ga Grenville orogenesis and subgreenschist-grade metamorphism in the Otish Basin but were present at low water/rock ratios at Camie River and therefore produced little alteration. Post-Grenville uplift of the Otish Basin likely produced late, low-temperature alteration minerals that have been influenced by recent meteoric water, suggesting that the fault zones and fractures the minerals occupy remain as preferential fluid-flow pathways to the present day.
Radiogenic Pb and the characteristic trace elements Mo + W + Nb have also preferentially dispersed from the mineralization along fault zones, fractures, and depositional sequence boundaries, and can be used to explore for Camie River-style U mineralization.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/401.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 427-457
Titre : Hydrologic, magmatic, and tectonic controls on hydrothermal flow, Taupo volcanic zone, New Zealand : implications for the formation of epithermal Vein deposits Type de document : texte imprimé Auteurs : Julie V. Rowland, Auteur ; Stuart F. Simmons, Auteur Année de publication : 2012 Article en page(s) : pp. 427-457 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Geothermal activity of Taupo volcanic zone Gold deposits Silver deposits Magmatism Volcanism New-Zeland Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : Geologic controls on development of high-flux hydrothermal conduits that promote epithermal ore formation are evaluated at large and small scales for geothermal systems of the Taupo Volcanic Zone, New Zealand. Most geothermal systems occur within a rifted volcanic arc (~150 km long) dominated by silicic volcanism, and they occur in association with major faults near caldera structures or within accommodation zones that transfer extension between rift segments. The geothermal systems are hosted in a thick sequence (1–>3 km) of young volcanic deposits that rest unconformably on weakly metamorphosed Mesozoic argillite and graywacke. Flow regimes and permeability controls in one extinct (Ohakuri) and six active (Broadlands-Ohaaki, Waiotapu, Rotokawa, Waimangu, Te Kopia, and Orakeikorako) geothermal systems show that in general, hydrothermal fluid flow is controlled by (1) heat from magmatic intrusions which drives convective circulation; (2) intergranular host-rock porosity and permeability; (3) fault-fracture network permeability produced by tectonism, volcanism, and/or diking; (4) pipelike vertical conduits produced by volcanic and hydrothermal eruptions; and (5) hydrothermal alteration and mineral deposition that may cause heterogeneity in the porosity and permeability of a fluid reservoir. Such controls influence fluid flow within three distinctive depth zones: (1) a feed zone (>2,000 m depth), (2) an epithermal mineralization zone (<200–2,000 m depth), and (3) a discharge zone (0–200 m depth). Within the deepest part of the feed zone, hydrothermal fluid flow is influenced by magmatic intrusions guided by faults, which localize convection cells, and the brittle-ductile transition at the base of the seismogenic zone, which limits downflow of meteoric water. Hydraulic connectivity through low-permeability Mesozoic rocks is favored along NNE- to ENE- and WNW- to NNW-striking structures given the NW-SE direction of maximum extension (~10 mm/yr). In the epithermal mineralization zone, high-flux structures extend upward from the feed zone and transmit fluids to shallow depths, analogous to a geothermal production well. The host stratigraphic interval is dominated by porous pyroclastic deposits and distributed flow can be widespread until the intergranular permeability is reduced by hydrothermal alteration or where dense, low-porosity, high-tensile strength rocks exist. Distributed fluid-flow accounts for large volumes of hydrothermal alteration extending 10 to >100 km3 that encloses geothermal reservoirs and high-flux fluid conduits. Fracture-dominated flow becomes important with decreasing porosity induced by hydrothermal alteration. In the discharge zone, the reduction in confining pressure, combined with mineral deposition and alteration, hydrothermal eruptions, and interplay of hot and cold waters create complex, but strongly localized flow paths that feed hot springs.
The permeability structure conducive to epithermal vein formation is analogous to a geothermal well: short in horizontal dimension (10s–100s m) but long in vertical dimension (>1,500 m) and possibly pipelike in shape. Episodic high-flux occurs over time scales of tens to thousands of years to accumulate sufficient amounts of gold and silver to form orebodies. During these episodes when faults and fractures are dilated, development of an upward-expanding column of boiling fluid promotes rapid ascent and high mass flow but also promotes silica and calcite precipitation, which can quickly reduce hydrothermal flow. Seismic activity and/or dike intrusion create and reactivate these high-flux pathways through extension and extensional shearing, caused by low differential stresses. The Taupo Volcanic Zone is highly prospective for epithermal-style mineralization, but the predominance of weak porous host rocks at shallow depths is prone to disseminated-style mineralization (e.g., Ohakuri). Structurally controlled mineralization forms in volcanic rocks where they have been embrittled by silicification through seismicity and fault displacement, caldera-forming eruptions, and dike intrusion.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/427.short [article] Hydrologic, magmatic, and tectonic controls on hydrothermal flow, Taupo volcanic zone, New Zealand : implications for the formation of epithermal Vein deposits [texte imprimé] / Julie V. Rowland, Auteur ; Stuart F. Simmons, Auteur . - 2012 . - pp. 427-457.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 427-457
Mots-clés : Geothermal activity of Taupo volcanic zone Gold deposits Silver deposits Magmatism Volcanism New-Zeland Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : Geologic controls on development of high-flux hydrothermal conduits that promote epithermal ore formation are evaluated at large and small scales for geothermal systems of the Taupo Volcanic Zone, New Zealand. Most geothermal systems occur within a rifted volcanic arc (~150 km long) dominated by silicic volcanism, and they occur in association with major faults near caldera structures or within accommodation zones that transfer extension between rift segments. The geothermal systems are hosted in a thick sequence (1–>3 km) of young volcanic deposits that rest unconformably on weakly metamorphosed Mesozoic argillite and graywacke. Flow regimes and permeability controls in one extinct (Ohakuri) and six active (Broadlands-Ohaaki, Waiotapu, Rotokawa, Waimangu, Te Kopia, and Orakeikorako) geothermal systems show that in general, hydrothermal fluid flow is controlled by (1) heat from magmatic intrusions which drives convective circulation; (2) intergranular host-rock porosity and permeability; (3) fault-fracture network permeability produced by tectonism, volcanism, and/or diking; (4) pipelike vertical conduits produced by volcanic and hydrothermal eruptions; and (5) hydrothermal alteration and mineral deposition that may cause heterogeneity in the porosity and permeability of a fluid reservoir. Such controls influence fluid flow within three distinctive depth zones: (1) a feed zone (>2,000 m depth), (2) an epithermal mineralization zone (<200–2,000 m depth), and (3) a discharge zone (0–200 m depth). Within the deepest part of the feed zone, hydrothermal fluid flow is influenced by magmatic intrusions guided by faults, which localize convection cells, and the brittle-ductile transition at the base of the seismogenic zone, which limits downflow of meteoric water. Hydraulic connectivity through low-permeability Mesozoic rocks is favored along NNE- to ENE- and WNW- to NNW-striking structures given the NW-SE direction of maximum extension (~10 mm/yr). In the epithermal mineralization zone, high-flux structures extend upward from the feed zone and transmit fluids to shallow depths, analogous to a geothermal production well. The host stratigraphic interval is dominated by porous pyroclastic deposits and distributed flow can be widespread until the intergranular permeability is reduced by hydrothermal alteration or where dense, low-porosity, high-tensile strength rocks exist. Distributed fluid-flow accounts for large volumes of hydrothermal alteration extending 10 to >100 km3 that encloses geothermal reservoirs and high-flux fluid conduits. Fracture-dominated flow becomes important with decreasing porosity induced by hydrothermal alteration. In the discharge zone, the reduction in confining pressure, combined with mineral deposition and alteration, hydrothermal eruptions, and interplay of hot and cold waters create complex, but strongly localized flow paths that feed hot springs.
The permeability structure conducive to epithermal vein formation is analogous to a geothermal well: short in horizontal dimension (10s–100s m) but long in vertical dimension (>1,500 m) and possibly pipelike in shape. Episodic high-flux occurs over time scales of tens to thousands of years to accumulate sufficient amounts of gold and silver to form orebodies. During these episodes when faults and fractures are dilated, development of an upward-expanding column of boiling fluid promotes rapid ascent and high mass flow but also promotes silica and calcite precipitation, which can quickly reduce hydrothermal flow. Seismic activity and/or dike intrusion create and reactivate these high-flux pathways through extension and extensional shearing, caused by low differential stresses. The Taupo Volcanic Zone is highly prospective for epithermal-style mineralization, but the predominance of weak porous host rocks at shallow depths is prone to disseminated-style mineralization (e.g., Ohakuri). Structurally controlled mineralization forms in volcanic rocks where they have been embrittled by silicification through seismicity and fault displacement, caldera-forming eruptions, and dike intrusion.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/427.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 459-480
Titre : Paragenesis, stable isotopes, and molybdenite Re-Os isotope age of the lala iron-copper deposit, southwest China Type de document : texte imprimé Auteurs : Wei Terry Chen, Auteur ; Mei-Fu Zhou, Auteur Année de publication : 2012 Article en page(s) : pp. 459-480 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Fe-Cu deposit Stable isotope geochemistry IOCG metallogenic province China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Lala Fe-Cu deposit in the Kangdian iron oxide copper-gold (IOCG) metallogenic province, SW China, is hosted in the Paleoproterozoic Hekou Group. This volcanic-sedimentary sequence has undergone upper greenschist-lower amphibolite facies metamorphism at ~850 Ma. The deposit contains more than 200 million metric tons (Mt) of Fe-Cu ores with an average grade of 13 wt % Fe and 0.92 wt % Cu. Orebodies are roughly strata bound but occur along foliation, lithologic contacts, and shear zones. The paragenetic sequence of the Lala deposit includes metamorphosed (I, II, and III) and unmetamorphosed (IV and V) stages. Stage I is characterized by extensively pervasive Na alteration, forming abundant albite but minor scapolite. Stage II occurs as massive and banded replacements, consists of Ti-V–poor magnetite and apatite with minor disseminated sulfide minerals, and was associated with pervasive K-Fe alterations forming K-feldspar, chlorite, and actinolite. Stage III occurs predominantly as bands and disseminations confined along foliations with minor veinlets cross-cutting hosting rocks. This stage is characterized by abundant Fe-Cu-Mo sulfides intergrown with angular magnetite and minor titanite and allanite and is associated with alteration of carbonate, quartz, fluorite, and mica. Stage IV has an assemblage dominated by chalcopyrite with variable pyrite and bornite, occurring as veins of sulfides + quartz + calcite + biotite ± muscovite ± fluorite. Stage V occurs chiefly as veins of hematite ± calcite ± quartz and also results in extensive hematization.
Stages II and III have fluids with high δ18O (7.2–11.7‰) and δ34S values (0–4‰), indicative of a magmatic-hydrothermal origin. However, the stage III fluids have δ34C values (~0.5‰) close to the least altered marble (0–2‰) of the hosting rocks, indicating a possible contribution of strata-sourced carbon. The stage IV fluids have δ34C values similar to and δ18O (4.1–6.7‰) lower than the stage III fluids, and a wider range of δ34S values (−9.0 to +10.5‰), consistent with significant contributions of strata-sourced sulfur. Fluids of the late barren vein stage (V) have relatively low δ34C (−4.0 to −2.4‰) and δ18O values (−2.9 to +0.6‰), indicative of significant contributions of meteoric and oxidized fluids.
Molybdenite from stage III has an Re-Os isotope age of 1086 ± 8 Ma, providing tight constraints on the timing of the main stage of mineralization. This age indicates that the Lala deposit is coeval with the ~1100 Ma intraplate magmatism in the western Yangtze Block. We propose that the majority of the Fe-Cu deposits in the Kangdian IOCG metallogenic province may have formed in an intraplate extensional setting, although it is possible that some of the deposits may have involved in multiple events including modification by the Neoproterozoic metamorphism forming the mineral assemblages of stage IV.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/459.short [article] Paragenesis, stable isotopes, and molybdenite Re-Os isotope age of the lala iron-copper deposit, southwest China [texte imprimé] / Wei Terry Chen, Auteur ; Mei-Fu Zhou, Auteur . - 2012 . - pp. 459-480.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 459-480
Mots-clés : Fe-Cu deposit Stable isotope geochemistry IOCG metallogenic province China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Lala Fe-Cu deposit in the Kangdian iron oxide copper-gold (IOCG) metallogenic province, SW China, is hosted in the Paleoproterozoic Hekou Group. This volcanic-sedimentary sequence has undergone upper greenschist-lower amphibolite facies metamorphism at ~850 Ma. The deposit contains more than 200 million metric tons (Mt) of Fe-Cu ores with an average grade of 13 wt % Fe and 0.92 wt % Cu. Orebodies are roughly strata bound but occur along foliation, lithologic contacts, and shear zones. The paragenetic sequence of the Lala deposit includes metamorphosed (I, II, and III) and unmetamorphosed (IV and V) stages. Stage I is characterized by extensively pervasive Na alteration, forming abundant albite but minor scapolite. Stage II occurs as massive and banded replacements, consists of Ti-V–poor magnetite and apatite with minor disseminated sulfide minerals, and was associated with pervasive K-Fe alterations forming K-feldspar, chlorite, and actinolite. Stage III occurs predominantly as bands and disseminations confined along foliations with minor veinlets cross-cutting hosting rocks. This stage is characterized by abundant Fe-Cu-Mo sulfides intergrown with angular magnetite and minor titanite and allanite and is associated with alteration of carbonate, quartz, fluorite, and mica. Stage IV has an assemblage dominated by chalcopyrite with variable pyrite and bornite, occurring as veins of sulfides + quartz + calcite + biotite ± muscovite ± fluorite. Stage V occurs chiefly as veins of hematite ± calcite ± quartz and also results in extensive hematization.
Stages II and III have fluids with high δ18O (7.2–11.7‰) and δ34S values (0–4‰), indicative of a magmatic-hydrothermal origin. However, the stage III fluids have δ34C values (~0.5‰) close to the least altered marble (0–2‰) of the hosting rocks, indicating a possible contribution of strata-sourced carbon. The stage IV fluids have δ34C values similar to and δ18O (4.1–6.7‰) lower than the stage III fluids, and a wider range of δ34S values (−9.0 to +10.5‰), consistent with significant contributions of strata-sourced sulfur. Fluids of the late barren vein stage (V) have relatively low δ34C (−4.0 to −2.4‰) and δ18O values (−2.9 to +0.6‰), indicative of significant contributions of meteoric and oxidized fluids.
Molybdenite from stage III has an Re-Os isotope age of 1086 ± 8 Ma, providing tight constraints on the timing of the main stage of mineralization. This age indicates that the Lala deposit is coeval with the ~1100 Ma intraplate magmatism in the western Yangtze Block. We propose that the majority of the Fe-Cu deposits in the Kangdian IOCG metallogenic province may have formed in an intraplate extensional setting, although it is possible that some of the deposits may have involved in multiple events including modification by the Neoproterozoic metamorphism forming the mineral assemblages of stage IV.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/459.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 481-506
Titre : Origin of PGE-poor and Cu-rich magmatic sulfides from the Kalatongke deposit, Xinjiang, northwest China Type de document : texte imprimé Auteurs : Jian-Feng Gao, Auteur ; Mei-Fu Zhou, Auteur ; Peter C. Lightfoot, Auteur Année de publication : 2012 Article en page(s) : pp. 481-506 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Cu-Ni sulfide deposit Magmatic sulfides China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Kalatongke Cu-Ni sulfide deposit in the Paleozoic Altay orogenic belt, NW China, is hosted in a Permian mafic intrusion consisting of norite, troctolite, gabbro, and diorite. Disseminated Ni-Cu, massive Ni-Cu, and massive Cu-rich sulfide ores are mainly hosted in norite and gabbro. Some massive Ni-Cu ores also occur in the Carboniferous sedimentary rocks. The geologic and compositional relationships between various sulfide ores and the rocks of Kalatongke offer a new interpretation of the sequence of emplacement of the magmas, which underpins an understanding of the compositions of the ores and the formation of the Kalatongke deposit.
Olivine grains from disseminated Ni-Cu ores have Fo values ranging from 71.6 to 78.0 mol % and Ni contents from 1,000 to 2,200 ppm. Typically, Ni decreases from the cores to the rims from 2,000 to 1,000 ppm at constant Fo content, indicating the reaction of early-formed olivine with later-segregated sulfide melt. Cr spinels at Kalatongke are highly enriched in Fe3+ and Fe2+, with relatively low Cr, Al, and Ti, reflecting reaction with evolved trapped intercumulus melt.
Norites are depleted in Nb, Ta, Zr, Hf, and Th and enriched in Sr and Ba, whereas disseminated Ni-Cu sulfide ores have considerable depletion of Rb and enrichment of Sr and Ba and lack depletion of Nb, Ta, Zr, and Hf, indicating their different origins. Disseminated Ni-Cu sulfide ores have bulk compositions with variable Cu and Ni contents which are much lower than those of massive Cu-rich and Ni-Cu ores, but disseminated and massive Ni-Cu ores have similar PGE contents with relatively low Pd/Ir ratios. Massive Cu-rich ores have much higher Pd and Pt with very high Pd/Ir ratios.
The Kalatongke Cu-Ni sulfide deposit appears to have formed from two different pulses of PGE-poor and Cu-rich basaltic magmas that underwent different degrees of assimilation and fractional crystallization. The first magma pulse gained sulfide saturation because of minor crustal contamination and fractionated a small amount of sulfide (<0.03%); the evolved melt then intruded and assimilated crustal materials to attain sulfide saturation again. Sulfide liquid segregated from the magma to form the massive sulfide melts and residual magma formed the noritic rocks in the shallow magma chamber. The segregated massive sulfide melts then underwent further fractionation to form massive Ni-Cu and massive Cu-rich ores. The second pulse of magma after removal of sulfides (<0.02%) experienced more crustal contamination and re attained S saturation. This new S-saturated and phenocryst-laden magma intruded the earlier formed massive sulfide ores and norites and formed the disseminated sulfide ores.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/481.short [article] Origin of PGE-poor and Cu-rich magmatic sulfides from the Kalatongke deposit, Xinjiang, northwest China [texte imprimé] / Jian-Feng Gao, Auteur ; Mei-Fu Zhou, Auteur ; Peter C. Lightfoot, Auteur . - 2012 . - pp. 481-506.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 481-506
Mots-clés : Cu-Ni sulfide deposit Magmatic sulfides China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Kalatongke Cu-Ni sulfide deposit in the Paleozoic Altay orogenic belt, NW China, is hosted in a Permian mafic intrusion consisting of norite, troctolite, gabbro, and diorite. Disseminated Ni-Cu, massive Ni-Cu, and massive Cu-rich sulfide ores are mainly hosted in norite and gabbro. Some massive Ni-Cu ores also occur in the Carboniferous sedimentary rocks. The geologic and compositional relationships between various sulfide ores and the rocks of Kalatongke offer a new interpretation of the sequence of emplacement of the magmas, which underpins an understanding of the compositions of the ores and the formation of the Kalatongke deposit.
Olivine grains from disseminated Ni-Cu ores have Fo values ranging from 71.6 to 78.0 mol % and Ni contents from 1,000 to 2,200 ppm. Typically, Ni decreases from the cores to the rims from 2,000 to 1,000 ppm at constant Fo content, indicating the reaction of early-formed olivine with later-segregated sulfide melt. Cr spinels at Kalatongke are highly enriched in Fe3+ and Fe2+, with relatively low Cr, Al, and Ti, reflecting reaction with evolved trapped intercumulus melt.
Norites are depleted in Nb, Ta, Zr, Hf, and Th and enriched in Sr and Ba, whereas disseminated Ni-Cu sulfide ores have considerable depletion of Rb and enrichment of Sr and Ba and lack depletion of Nb, Ta, Zr, and Hf, indicating their different origins. Disseminated Ni-Cu sulfide ores have bulk compositions with variable Cu and Ni contents which are much lower than those of massive Cu-rich and Ni-Cu ores, but disseminated and massive Ni-Cu ores have similar PGE contents with relatively low Pd/Ir ratios. Massive Cu-rich ores have much higher Pd and Pt with very high Pd/Ir ratios.
The Kalatongke Cu-Ni sulfide deposit appears to have formed from two different pulses of PGE-poor and Cu-rich basaltic magmas that underwent different degrees of assimilation and fractional crystallization. The first magma pulse gained sulfide saturation because of minor crustal contamination and fractionated a small amount of sulfide (<0.03%); the evolved melt then intruded and assimilated crustal materials to attain sulfide saturation again. Sulfide liquid segregated from the magma to form the massive sulfide melts and residual magma formed the noritic rocks in the shallow magma chamber. The segregated massive sulfide melts then underwent further fractionation to form massive Ni-Cu and massive Cu-rich ores. The second pulse of magma after removal of sulfides (<0.02%) experienced more crustal contamination and re attained S saturation. This new S-saturated and phenocryst-laden magma intruded the earlier formed massive sulfide ores and norites and formed the disseminated sulfide ores.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/481.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 507-524
Titre : Whole-rock and mineral composition constraints on the genesis of the giant hongge Fe-Ti-V oxide deposit in the Emeishan large igneous province, southwest China Type de document : texte imprimé Auteurs : Zhong-Jie Bai, Auteur ; Zhong Hong, Auteur ; Anthony J. Naldrett, Auteur Année de publication : 2012 Article en page(s) : pp. 507-524 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Fe-Ti-V oxide ore deposit Whole rock Mineral composition China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Hongge giant Fe-Ti-V oxide ore deposit is hosted by a layered intrusion located in the central part of the Emeishan large igneous province, SW China. The intrusion is relatively small in comparison with other typical oxide-bearing intrusions worldwide; it consists of a lower olivine clinopyroxenite zone, a middle clinopyroxenite zone, and an upper gabbro zone (herein referred to as the lower, middle, and upper zones). Most of the economic Fe-Ti-V oxide ore layers occur within the middle zone. The Hongge oxide ores are depleted in REE and enriched in Zr, Hf, Nb, and Ta as compared to the associated clinopyroxenites. This enrichment of elements that are compatible in titanomagnetite is consistent with the interpretation that the ores formed by accumulation of magnetite and ilmenite. As in the nearby coeval Panzhihua Fe-Ti-V oxide deposit described previously by others, mafic silicates in the Hongge deposit have much higher MgO contents than those in other oxide deposits associated with large layered intrusions in the world. This highlights the importance of relatively primitive parental magma becoming saturated in titanomagnetite at an early stage in the genesis of the giant Fe-Ti-V oxide deposits in the Emeishan large igneous province. Phase equilibrium constraints suggest that the parental magma of the Hongge deposit is similar to that of some of the most primitive high Ti basalts in the Emeishan large igneous province. The ferrobasaltic parental magma and the ferropicritic primary magma of the Hongge intrusion are similar in major and trace element composition to the ferropicritic-ferrobasaltic magma in the Pechenga belt, Kola peninsula, Russia. Depletion of incompatible trace elements in the oxide ores and associated rocks in the Hongge intrusion as compared to the coeval high-Ti basalts suggest that not all the magma involved in the development of the Hongge intrusion has been retained in the intrusion. The occurrence of multiple Fe-Ti oxide layers alternating with Fe-Ti oxide-bearing silicate layers within a single zone and the repetitive appearance of sulfides, olivine, and Cr-rich layers suggest that multiple pulses of magma were involved in the formation of the Hongge intrusion and related Fe-Ti-V oxide deposit. We propose that the middle zone of the Hongge intrusion was a magma stepwise flow-through system and that some of the liquid was lost to the peripheral lavas to form the basalt. DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/507.short [article] Whole-rock and mineral composition constraints on the genesis of the giant hongge Fe-Ti-V oxide deposit in the Emeishan large igneous province, southwest China [texte imprimé] / Zhong-Jie Bai, Auteur ; Zhong Hong, Auteur ; Anthony J. Naldrett, Auteur . - 2012 . - pp. 507-524.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 507-524
Mots-clés : Fe-Ti-V oxide ore deposit Whole rock Mineral composition China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Hongge giant Fe-Ti-V oxide ore deposit is hosted by a layered intrusion located in the central part of the Emeishan large igneous province, SW China. The intrusion is relatively small in comparison with other typical oxide-bearing intrusions worldwide; it consists of a lower olivine clinopyroxenite zone, a middle clinopyroxenite zone, and an upper gabbro zone (herein referred to as the lower, middle, and upper zones). Most of the economic Fe-Ti-V oxide ore layers occur within the middle zone. The Hongge oxide ores are depleted in REE and enriched in Zr, Hf, Nb, and Ta as compared to the associated clinopyroxenites. This enrichment of elements that are compatible in titanomagnetite is consistent with the interpretation that the ores formed by accumulation of magnetite and ilmenite. As in the nearby coeval Panzhihua Fe-Ti-V oxide deposit described previously by others, mafic silicates in the Hongge deposit have much higher MgO contents than those in other oxide deposits associated with large layered intrusions in the world. This highlights the importance of relatively primitive parental magma becoming saturated in titanomagnetite at an early stage in the genesis of the giant Fe-Ti-V oxide deposits in the Emeishan large igneous province. Phase equilibrium constraints suggest that the parental magma of the Hongge deposit is similar to that of some of the most primitive high Ti basalts in the Emeishan large igneous province. The ferrobasaltic parental magma and the ferropicritic primary magma of the Hongge intrusion are similar in major and trace element composition to the ferropicritic-ferrobasaltic magma in the Pechenga belt, Kola peninsula, Russia. Depletion of incompatible trace elements in the oxide ores and associated rocks in the Hongge intrusion as compared to the coeval high-Ti basalts suggest that not all the magma involved in the development of the Hongge intrusion has been retained in the intrusion. The occurrence of multiple Fe-Ti oxide layers alternating with Fe-Ti oxide-bearing silicate layers within a single zone and the repetitive appearance of sulfides, olivine, and Cr-rich layers suggest that multiple pulses of magma were involved in the formation of the Hongge intrusion and related Fe-Ti-V oxide deposit. We propose that the middle zone of the Hongge intrusion was a magma stepwise flow-through system and that some of the liquid was lost to the peripheral lavas to form the basalt. DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/507.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 525-535
Titre : Ion microprobe U-Pb age and Zr-in-rutile thermometry of rutiles from the daixian rutile deposit in the Hengshan mountains, Shanxi province, China Type de document : texte imprimé Auteurs : Guanghai Shi, Auteur ; Xianhua Li, Auteur ; Qiuli Li, Auteur Année de publication : 2012 Article en page(s) : pp. 525-535 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Dixian rutile deposit Magnetite-ilmenite ore U-Pb age Zr-in rutile China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Daixian rutile deposit is located in the Hengshan Mountains in the Trans-North China Orogen; it is considered to be one of the largest rutile deposits in China, with 6 million metric tons (Mt) of contained titanium. Most of the rutile ores are hosted in garnet-free anthophyllite gneiss with minor Mg hornblende, feldspar, quartz, phlogopite, rutile, zircon, and titanite. Rutile grains are euhedral, 0.02 to 0.50 mm in size, contain 98.649 to 99.784 wt % TiO2, and form chains, thin layers along the foliation, and dense aggregates. Rutiles are compositionally homogeneous and contain no detectable mineral inclusions except local ilmenite lamellae and zircon. Crystallization temperatures of the rutile are estimated at ~640°C at 0.7 GPa, and ~647°C without pressure calibration according to the Zr-in-rutile thermometer, recording amphibolite facies metamorphism of an intermediate P/T ratio series. Variations in Nb versus Cr in rutiles indicate a connection of the ores to mafic protolith; not a pelitic rock derived from aluminous sedimentary rocks. SIMS U-Pb analyses of rutiles from the deposit yield a mean 207Pb/207Pb age of 1780.2 ± 9.6 Ma. Considering the closure temperature (up to ~650°C), grain sizes and recrystallization of the rutile, this age is more likely to represent closure and/or recrystallization time rather than peak metamorphism period, so the rutile deposit formed not younger than ~1780 Ma. This unique garnet-free rutile deposit was metamorphosed from mafic rocks in amphibolite facies during the Paleoproterozoic or Archean, being distinct from any other metamorphic rutile deposits, such as the known eclogite-related types. DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/525.short [article] Ion microprobe U-Pb age and Zr-in-rutile thermometry of rutiles from the daixian rutile deposit in the Hengshan mountains, Shanxi province, China [texte imprimé] / Guanghai Shi, Auteur ; Xianhua Li, Auteur ; Qiuli Li, Auteur . - 2012 . - pp. 525-535.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 525-535
Mots-clés : Dixian rutile deposit Magnetite-ilmenite ore U-Pb age Zr-in rutile China Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Daixian rutile deposit is located in the Hengshan Mountains in the Trans-North China Orogen; it is considered to be one of the largest rutile deposits in China, with 6 million metric tons (Mt) of contained titanium. Most of the rutile ores are hosted in garnet-free anthophyllite gneiss with minor Mg hornblende, feldspar, quartz, phlogopite, rutile, zircon, and titanite. Rutile grains are euhedral, 0.02 to 0.50 mm in size, contain 98.649 to 99.784 wt % TiO2, and form chains, thin layers along the foliation, and dense aggregates. Rutiles are compositionally homogeneous and contain no detectable mineral inclusions except local ilmenite lamellae and zircon. Crystallization temperatures of the rutile are estimated at ~640°C at 0.7 GPa, and ~647°C without pressure calibration according to the Zr-in-rutile thermometer, recording amphibolite facies metamorphism of an intermediate P/T ratio series. Variations in Nb versus Cr in rutiles indicate a connection of the ores to mafic protolith; not a pelitic rock derived from aluminous sedimentary rocks. SIMS U-Pb analyses of rutiles from the deposit yield a mean 207Pb/207Pb age of 1780.2 ± 9.6 Ma. Considering the closure temperature (up to ~650°C), grain sizes and recrystallization of the rutile, this age is more likely to represent closure and/or recrystallization time rather than peak metamorphism period, so the rutile deposit formed not younger than ~1780 Ma. This unique garnet-free rutile deposit was metamorphosed from mafic rocks in amphibolite facies during the Paleoproterozoic or Archean, being distinct from any other metamorphic rutile deposits, such as the known eclogite-related types. DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/525.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 537-551
Titre : Skarn gold mineralization at the geodo mine, south Korea Type de document : texte imprimé Auteurs : Eui-Jun Kim, Auteur ; Maeng-Eon Park, Auteur ; Noel C. White, Auteur Année de publication : 2012 Article en page(s) : pp. 537-551 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Bi-Te-bearing skarn deposit Gold deposit Geodo skarn Korea Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Geodo Bi-Te–bearing skarn deposit is located in the Taebaeksan mining district, South Korea. Both endoskarn and exoskarn are associated with the Cretaceous Eopyeong granitoids, which consist of magnetite-bearing oxidized (Fe2O3/FeO > 0.4) quartz monzodiorite to monzodiorite.
Gold in the Geodo Mine occurs in a retrograde alteration stage within a garnet-rich proximal zone. Skarn minerals associated with gold ore include Fe-rich garnet (Ad57–95Gr1–41) and a wide range of clinopyroxene (Hd20–100Di0–79) compositions, broadly similar to those of typical gold-bearing skarn deposits. The paragenetic stages of the Bi- and Te-bearing skarn in the Geodo Mine consist of early calc-silicate alteration followed by three mineralization stages: Fe oxide, Cu rich, and Au rich. The Fe oxide and Cu-rich stages were deposited at higher temperatures than the Au-rich stage, based on mineral assemblage stabilities. Gold in Au-rich ores from the Geodo Mine occurs as native gold, ranging from 5 to 400 μm in diameter, and is closely related to the Bi- and Te-bearing minerals bismuthinite and tetradymite, which at Geodo tend to be strongly enriched in Bi and depleted in S compared to ideal compositions. This association of gold with bismuthinite and tetradymite suggests that gold was deposited at relatively low temperatures, consistent with fluid inclusion studies on calcite that indicate that the gold was deposited from fluids ranging from 181° to 281°C and 8.0 to 10.9 wt % NaCl equiv, and with chlorite geothermometry indicating a range of 198° to 211°C. The presence of significant amounts of Bi- and Te-bearing minerals associated with Au suggests that liquid bismuth may have acted as a collector, increasing the concentration of gold.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/537.short [article] Skarn gold mineralization at the geodo mine, south Korea [texte imprimé] / Eui-Jun Kim, Auteur ; Maeng-Eon Park, Auteur ; Noel C. White, Auteur . - 2012 . - pp. 537-551.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - pp. 537-551
Mots-clés : Bi-Te-bearing skarn deposit Gold deposit Geodo skarn Korea Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : The Geodo Bi-Te–bearing skarn deposit is located in the Taebaeksan mining district, South Korea. Both endoskarn and exoskarn are associated with the Cretaceous Eopyeong granitoids, which consist of magnetite-bearing oxidized (Fe2O3/FeO > 0.4) quartz monzodiorite to monzodiorite.
Gold in the Geodo Mine occurs in a retrograde alteration stage within a garnet-rich proximal zone. Skarn minerals associated with gold ore include Fe-rich garnet (Ad57–95Gr1–41) and a wide range of clinopyroxene (Hd20–100Di0–79) compositions, broadly similar to those of typical gold-bearing skarn deposits. The paragenetic stages of the Bi- and Te-bearing skarn in the Geodo Mine consist of early calc-silicate alteration followed by three mineralization stages: Fe oxide, Cu rich, and Au rich. The Fe oxide and Cu-rich stages were deposited at higher temperatures than the Au-rich stage, based on mineral assemblage stabilities. Gold in Au-rich ores from the Geodo Mine occurs as native gold, ranging from 5 to 400 μm in diameter, and is closely related to the Bi- and Te-bearing minerals bismuthinite and tetradymite, which at Geodo tend to be strongly enriched in Bi and depleted in S compared to ideal compositions. This association of gold with bismuthinite and tetradymite suggests that gold was deposited at relatively low temperatures, consistent with fluid inclusion studies on calcite that indicate that the gold was deposited from fluids ranging from 181° to 281°C and 8.0 to 10.9 wt % NaCl equiv, and with chlorite geothermometry indicating a range of 198° to 211°C. The presence of significant amounts of Bi- and Te-bearing minerals associated with Au suggests that liquid bismuth may have acted as a collector, increasing the concentration of gold.DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/537.short
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - p. 553
Titre : Biogeochemistry of uranium deposits and methodological fundamentals of their prospecting Type de document : texte imprimé Auteurs : Gregory Levita, Auteur Année de publication : 2012 Article en page(s) : p. 553 Note générale : Economic geology Langues : Anglais (eng) Mots-clés : Uranium deposits Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Note de contenu : Book reviews DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/553.1.short [article] Biogeochemistry of uranium deposits and methodological fundamentals of their prospecting [texte imprimé] / Gregory Levita, Auteur . - 2012 . - p. 553.
Economic geology
Langues : Anglais (eng)
in Economic geology > Vol. 107 N° 3 (Mai 2012) . - p. 553
Mots-clés : Uranium deposits Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Note de contenu : Book reviews DEWEY : 553 ISSN : 0361-0128 En ligne : http://econgeol.geoscienceworld.org/content/107/3/553.1.short
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