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Hong Cheng - One of the best experts on this subject based on the ideXlab platform.
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SHRIMP U–Pb zircon dating of the Wulian complex: Defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2008Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian-Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U-Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700-2400 Ma, with a peak at 2436 Ma; 2200-1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U-Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206Pb/ 238U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe-Yantai Fault. © 2007.link_to_subscribed_fulltex
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SHRIMP U-Pb zircon dating of the Wulian Complex: defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2007Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Abstract Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian–Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U–Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700–2400 Ma, with a peak at 2436 Ma; 2200–1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U–Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206 Pb/ 238 U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe–Yantai Fault.
Guochun Zhao - One of the best experts on this subject based on the ideXlab platform.
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Tectonic implications of new zircon U–Pb ages for the Xinghuadukou Complex, Erguna Massif, northern Great Xing’an Range, NE China
Journal of Asian Earth Sciences, 2015Co-Authors: Jing-sheng Chen, Hao Yang, Guochun Zhao, Yan-long Zhang, De-xin TianAbstract:Abstract The nature and the timing of formation of the Xinghuadukou Complex of NE China are important to further our understanding of the Precambrian geological evolution of the Erguna Massif and the eastern segment of the Central Asian Orogenic Belt (CAOB). Here, we present the results of zircon U–Pb dating of a Metavolcanic Rock and 11 granitoid basement samples collected from the complex. We use these data to determine the age and tectonic origin of the complex and to examine the linkages between this complex and the surrounding tectonic domains and older cratonic areas. Igneous zircons from the Metavolcanic Rock yield a magmatic age of ∼850 Ma, indicating that the supracrustal Rocks that represent the original Xinghuadukou Group formed during the Neoproterozoic. Petrological data and new zircon U–Pb ages for these samples enabled the identification of multiple stages of granitoid magmatism within different sections of the Xinghuadukou “Group”, indicating that this group, which was originally thought to have formed contemporaneously actually records the emplacement of granitoids at 957–786, 479–418, 265, and 209–192 Ma. This result indicates that the Xinghuadukou Complex records multiple stages of magmatism and contains various Neoproterozoic supracrustal components. Combining the new age data with regional geological data, we propose that the Erguna Massif should be considered part of the Mongol domain as it has a close affinity to other blocks that formed part of this domain during the Neoproterozoic. These data suggest that all of the complexes and terranes within the Mongol domain belong to the CAOB and were finally accreted to the southern margin of the Siberian Craton in the early Paleozoic.
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SHRIMP U–Pb zircon dating of the Wulian complex: Defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2008Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian-Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U-Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700-2400 Ma, with a peak at 2436 Ma; 2200-1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U-Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206Pb/ 238U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe-Yantai Fault. © 2007.link_to_subscribed_fulltex
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SHRIMP U-Pb zircon dating of the Wulian Complex: defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2007Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Abstract Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian–Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U–Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700–2400 Ma, with a peak at 2436 Ma; 2200–1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U–Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206 Pb/ 238 U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe–Yantai Fault.
Jian-bo Zhou - One of the best experts on this subject based on the ideXlab platform.
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SHRIMP U–Pb zircon dating of the Wulian complex: Defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2008Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian-Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U-Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700-2400 Ma, with a peak at 2436 Ma; 2200-1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U-Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206Pb/ 238U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe-Yantai Fault. © 2007.link_to_subscribed_fulltex
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SHRIMP U-Pb zircon dating of the Wulian Complex: defining the boundary between the North and South China Cratons in the Sulu Orogenic Belt, China
Precambrian Research, 2007Co-Authors: Jian-bo Zhou, Guochun Zhao, Simon A. Wilde, Xing-zhou Zhang, Chang-qing Zheng, Wei Jin, Hong ChengAbstract:Abstract Neoproterozoic metasedimentary and Metavolcanic Rocks of the Wulian Group are associated with gneissic granitoids at the northern margin of the Sulu UHP Belt, adjacent to the Wulian–Yantai Fault, and are collectively referred to as the Wulian complex. SHRIMP U–Pb dating of detrital zircon from the metasedimentary Rocks of the Wulian Group indicates a range in age from 3478 to 625 Ma. Based on zircons 3000 Ma, with the oldest age being 3339 Ma; 2700–2400 Ma, with a peak at 2436 Ma; 2200–1800 Ma, with a peak at ∼2156 Ma; and at ∼770 Ma. These results indicate that deposition of the Wulian Group was after ∼770 Ma and that some detrital material most likely came from Neoproterozoic sources in the South China Craton (SCC). SHRIMP U–Pb zircon dating of a Metavolcanic Rock defines a weighted mean 206 Pb/ 238 U age of 761 ± 8 Ma, which is consistent with other Rocks of South China affinity and can be correlated with syn-rift magmatism during the breakup of the supercontinent Rodinia. The Wulian Group, together with Neoproterozoic granites of the Wulian complex, constrains the location of the Triassic suture zone between the North China and South China Cratons. Based on our new data, the suture must lie north of the Wulian complex and is marked by the Baichihe–Yantai Fault.
Hendrik Falck - One of the best experts on this subject based on the ideXlab platform.
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Deciphering the Complex Fluid History of a Greenstone-Hosted Gold Deposit: Fluid Inclusion and Stable Isotope Studies of the Giant Mine, Yellowknife, Northwest Territories, Canada
Economic Geology, 2004Co-Authors: Kevin L. Shelton, Edmond H. P. Van Hees, Todd A. Mcmenamy, Hendrik FalckAbstract:Mesothermal, greenstone-hosted gold deposits are typically products of complex hydrothermal systems that involved multiple fluids at various times throughout their histories. The Giant mine is an example of such an extremely complicated system, including (1) multiple, local and regional gold-depositing events; (2) at least two styles of gold ore introduction in the mine area, including both refractory, sulfide-hosted and free-milling, vein-hosted ores, whose relative timing is enigmatic; (3) fluid overprinting associated with deposition of multiple generations of postore vein- and vug-filling minerals; and (4) postore deformation and recrystallization of ore veins, especially along faults. Three main stages of quartz-carbonate mineralization are recognized in the Giant mine. Stage I encompasses deposition of dominant refractory, sulfide-hosted ores and subordinate free-milling, vein-hosted gold ores. Refractory, Metavolcanic Rock-hosted orebodies are connected to metasedimentary Rocks east of the mine by an east-dipping alteration zone characterized by a depletion in Na and enrichments in K, Ag, As, S, and Sb. Quartz veins within the wall-Rock alteration zone have δ 18 O values that decrease systematically from 14.7 per mil in deeper metasedimentary Rocks toward 11.6 per mil in shallower metabasalts in the mine. This decrease is interpreted to indicate that 18 O-enriched ore fluids originated in deeper, metasedimentary Rocks and reacted extensively with wall Rocks along the entire extent of their flow paths before depositing dominantly refractory gold ores within more 16 O-enriched, shallower, Ti-rich tholeiitic metabasalts. Quartz ± carbonate veins related to these gold ores were deposited from H 2 O-CO 2 -NaCl fluids with T h values of 180° to 360°C and salinities of 4 to 9 wt percent NaCl equiv. Evidence of sporadic fluid unmixing indicates that gold was deposited at temperatures near 350°C and pressures of 1 to 2 kbars. The δ 18 O values (SMOW) of vein quartz (11.6–14.7‰) and calcite (8.6–14.1‰) within the ore-related wall-Rock alteration zone indicate deposition from fluids ( δ 18 O water = 4.4–9.8‰) that equilibrated with metasedimentary and Metavolcanic Rocks during greenschist metamorphism. The δ 18 O values (8.6–11.4‰) of vein quartz that locally contains free gold, hosted in Metavolcanic Rocks outside of the ore-related alteration zone, indicate deposition from fluids with lower δ 8 O water values of 2.8 to 5.6 per mil. The difference in ranges of δ 18 O water values may indicate that multiple events were responsible for gold-bearing quartz veining, or alternatively, that fluids depositing veins within and outside of the alteration zone represented distinct fluid reservoirs that evolved through reaction with isotopically distinct Rocks in their source regions (i.e., 18 O-enriched metasedimentary vs. 16 O-enriched Metavolcanic Rocks). Postore (stage II) carbonate veins associated with minor Pb-Zn-Sb-Ag mineralization were deposited from highly saline NaCl-CaCl 2 brines with T m values of –32° to –36°C and T h values of 72° to 273°C. The δ 18 O values of these carbonates (20.6–26.1‰) indicate that their parent brines ( δ 18 O water = 9–14‰) also equilibrated with metasedimentary and Metavolcanic Rocks. Subsequent dissolution of these carbonate veins created abundant vuggy porosity. Late (stage III), primarily vug-filling dolomite ± stibnite, overgrown by scalenohedral calcite, was deposited from dilute fluids ( h values of 95° to 115°C. The δ 18 O values of dolomite (17.4 toward 13.4‰) and latest calcite (10.9‰) indicate deposition from progressively less evolved meteoric waters with decreasing δ 18 O values from 1.1 toward –6.9 per mil. Refractory ores in the main alteration zone and gold-bearing quartz veins contained therein formed from chemically similar CO 2 -H 2 O-NaCl ore fluids whose oxygen isotope compositions are consistent with a metasedimentary source. These two styles of gold mineralization appear to be part of the same mineralizing event in which the style of mineralization was dictated by the mechanism of ore deposition. Refractory, sulfide-hosted gold mineralization resulted from reaction of mineralizing fluids with Metavolcanic wall-Rock Fe 2+ . Free-milling, gold-bearing quartz vein ores were deposited as a result of fluid unmixing, with loss of H 2 S to the vapor phase. Gold-bearing quartz veins outside of the main wall-Rock alteration zone in the Giant mine were also deposited by unmixing of similar H 2 O-CO 2 -NaCl fluids. However, these fluids were isotopically distinct from those within the alteration zone and may not be part of the refractory, sulfide-hosted gold-depositing event. They may instead represent a separate mineralizing event whose fluids and ore-forming constituents were derived solely from within Metavolcanic Rocks. This overprinting of one event on the other may have been a necessary condition for the development of world-class gold deposits in the Yellowknife district. The important roles of both Metavolcanic and metasedimentary source Rocks may explain why some smaller greenstone belts, with limited volumes of Metavolcanic Rocks, can host substantial economic gold mineralization and has important implications for regional resource evaluation and exploration for gold deposits in greenstone belts.
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Metasedimentary influence on Metavolcanic-Rock–hosted greenstone gold deposits: Geochemistry of the Giant mine, Yellowknife, Northwest Territories, Canada
Geology, 1999Co-Authors: Edmond H. P. Van Hees, Kevin L. Shelton, Todd A. Mcmenamy, Louis M. Ross, Brian Cousens, Hendrik Falck, Malcolm E. Robb, Tim W. CanamAbstract:The Giant mine is a mesothermal, greenstone-hosted gold deposit that has produced ~250 metric tons of gold, principally from sulfide ores in altered Metavolcanic Rocks. Previous studies concluded that mineralizing fluids acquired metals and other ore-forming components from within the ore-hosting Metavolcanic Rocks and ascended a steep-dipping shear zone to the site of ore deposition. Our studies indicate that although the Metavolcanic host Rocks were important geochemically in the precipitation of gold, extensive metasedimentary Rocks to the east were a more important conduit and/or source of fluids, metals, and ore-forming constituents. Geochemical analyses reveal an east-dipping Na depletion zone extending from the ore zone to within the metasedimentary sequence that coincides with enrichments in Ag, As, S, and Sb and with δ 18 O quartz values of 11.7‰ to 14.1‰. These data indicate that wall-Rock‐hosted gold mineralization was deposited where fluids emerging from metasedimentary Rocks encountered highly reactive Ti-rich tholeiitic basalts. From a geochemical standpoint, this ore system represents a metasedimentary-type gold deposit hosted in Metavolcanic Rocks. Documentation of a metasedimentary influence on formation of the minerals of the Giant mine helps explain why smaller greenstone belts can host substantial economic gold mineralization and has important implications for exploration for giant (>150 t) gold deposits.
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metasedimentary influence on Metavolcanic Rock hosted greenstone gold deposits geochemistry of the giant mine yellowknife northwest territories canada
Geology, 1999Co-Authors: Edmond H. P. Van Hees, Kevin L. Shelton, Todd A. Mcmenamy, Louis M. Ross, Brian Cousens, Hendrik Falck, Malcolm E. Robb, Tim W. CanamAbstract:The Giant mine is a mesothermal, greenstone-hosted gold deposit that has produced ~250 metric tons of gold, principally from sulfide ores in altered Metavolcanic Rocks. Previous studies concluded that mineralizing fluids acquired metals and other ore-forming components from within the ore-hosting Metavolcanic Rocks and ascended a steep-dipping shear zone to the site of ore deposition. Our studies indicate that although the Metavolcanic host Rocks were important geochemically in the precipitation of gold, extensive metasedimentary Rocks to the east were a more important conduit and/or source of fluids, metals, and ore-forming constituents. Geochemical analyses reveal an east-dipping Na depletion zone extending from the ore zone to within the metasedimentary sequence that coincides with enrichments in Ag, As, S, and Sb and with δ 18 O quartz values of 11.7‰ to 14.1‰. These data indicate that wall-Rock‐hosted gold mineralization was deposited where fluids emerging from metasedimentary Rocks encountered highly reactive Ti-rich tholeiitic basalts. From a geochemical standpoint, this ore system represents a metasedimentary-type gold deposit hosted in Metavolcanic Rocks. Documentation of a metasedimentary influence on formation of the minerals of the Giant mine helps explain why smaller greenstone belts can host substantial economic gold mineralization and has important implications for exploration for giant (>150 t) gold deposits.
Tim W. Canam - One of the best experts on this subject based on the ideXlab platform.
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Metasedimentary influence on Metavolcanic-Rock–hosted greenstone gold deposits: Geochemistry of the Giant mine, Yellowknife, Northwest Territories, Canada
Geology, 1999Co-Authors: Edmond H. P. Van Hees, Kevin L. Shelton, Todd A. Mcmenamy, Louis M. Ross, Brian Cousens, Hendrik Falck, Malcolm E. Robb, Tim W. CanamAbstract:The Giant mine is a mesothermal, greenstone-hosted gold deposit that has produced ~250 metric tons of gold, principally from sulfide ores in altered Metavolcanic Rocks. Previous studies concluded that mineralizing fluids acquired metals and other ore-forming components from within the ore-hosting Metavolcanic Rocks and ascended a steep-dipping shear zone to the site of ore deposition. Our studies indicate that although the Metavolcanic host Rocks were important geochemically in the precipitation of gold, extensive metasedimentary Rocks to the east were a more important conduit and/or source of fluids, metals, and ore-forming constituents. Geochemical analyses reveal an east-dipping Na depletion zone extending from the ore zone to within the metasedimentary sequence that coincides with enrichments in Ag, As, S, and Sb and with δ 18 O quartz values of 11.7‰ to 14.1‰. These data indicate that wall-Rock‐hosted gold mineralization was deposited where fluids emerging from metasedimentary Rocks encountered highly reactive Ti-rich tholeiitic basalts. From a geochemical standpoint, this ore system represents a metasedimentary-type gold deposit hosted in Metavolcanic Rocks. Documentation of a metasedimentary influence on formation of the minerals of the Giant mine helps explain why smaller greenstone belts can host substantial economic gold mineralization and has important implications for exploration for giant (>150 t) gold deposits.
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metasedimentary influence on Metavolcanic Rock hosted greenstone gold deposits geochemistry of the giant mine yellowknife northwest territories canada
Geology, 1999Co-Authors: Edmond H. P. Van Hees, Kevin L. Shelton, Todd A. Mcmenamy, Louis M. Ross, Brian Cousens, Hendrik Falck, Malcolm E. Robb, Tim W. CanamAbstract:The Giant mine is a mesothermal, greenstone-hosted gold deposit that has produced ~250 metric tons of gold, principally from sulfide ores in altered Metavolcanic Rocks. Previous studies concluded that mineralizing fluids acquired metals and other ore-forming components from within the ore-hosting Metavolcanic Rocks and ascended a steep-dipping shear zone to the site of ore deposition. Our studies indicate that although the Metavolcanic host Rocks were important geochemically in the precipitation of gold, extensive metasedimentary Rocks to the east were a more important conduit and/or source of fluids, metals, and ore-forming constituents. Geochemical analyses reveal an east-dipping Na depletion zone extending from the ore zone to within the metasedimentary sequence that coincides with enrichments in Ag, As, S, and Sb and with δ 18 O quartz values of 11.7‰ to 14.1‰. These data indicate that wall-Rock‐hosted gold mineralization was deposited where fluids emerging from metasedimentary Rocks encountered highly reactive Ti-rich tholeiitic basalts. From a geochemical standpoint, this ore system represents a metasedimentary-type gold deposit hosted in Metavolcanic Rocks. Documentation of a metasedimentary influence on formation of the minerals of the Giant mine helps explain why smaller greenstone belts can host substantial economic gold mineralization and has important implications for exploration for giant (>150 t) gold deposits.