Geochronological, Petrological, and Geochemical Constraints on Ni-Cu Sulfide Mineralization in the Poyi Ultramafic-Troctolitic Intrusion in the Northeast Rim of the Tarim Craton, Western China

2016 ◽  
Vol 111 (6) ◽  
pp. 1465-1484 ◽  
Author(s):  
Shengchao Xue ◽  
Kezhang Qin ◽  
Chusi Li ◽  
Dongmei Tang ◽  
Yajing Mao ◽  
...  
Keyword(s):  
Western China ◽  
Sulfide Mineralization ◽  
Tarim Craton ◽  
Geochemical Constraints

scholarly journals The Petrogenesis of the Permian Podong Ultramafic Intrusion in the Tarim Craton, Western China: Constraints from C-He-Ne-Ar Isotopes

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Mingjie Zhang ◽  
Pengyu Feng ◽  
Tong Li ◽  
Liwu Li ◽  
Juerong Fu ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Mantle Plume ◽  
Mantle Source ◽  
Noble Gas ◽  
Western China ◽  
Crustal Material ◽  
Sulfide Mineralization ◽  
Hydrocarbon Gases ◽  
Isotopic Compositions ◽  
Ultramafic Intrusion

The Podong Permian ultramafic intrusion is only one ultramafic intrusion with massif Ni-Cu sulfide mineralization in the Pobei layered mafic-ultramafic complex, western China. It is obviously different in sulfide mineralization from the nearby coeval Poyi ultramafic intrusion with the largest disseminated Ni-Cu sulfide mineralization and mantle plume contribution (Zhang et al., 2017). The type and addition mechanism of the confirmed crustal contaminations and possible mantle plume involved in the intrusion formation require evidences from carbon and noble gas isotopic compositions. In the present study, we have measured C, He, Ne, and Ar isotopic compositions of volatiles from magmatic minerals in the Podong ultramafic intrusion. The results show that olivine, pyroxene, and plagioclase minerals in the Podong intrusion have variable δ13C of CO2 (-24.5‰ to -3.2‰). The CH4, C2H6, C3H8, and C4H10 hydrocarbon gases show normal or partial reversal distribution patterns of carbon isotope with carbon number and light δ13C1 value of CH4, indicating the hydrocarbon gases of biogenic origin. The δ13C of CO2 and CH4 suggested the magmatic volatile of the mantle mixed with the volatiles of thermogenic and crustal origins. Carbon and noble gas isotopes indicated that the Podong intrusion could have a different petrogenesis from the Poyi ultramafic intrusion. Two types of contaminated crustal materials can be identified as crustal fluids from subducted altered oceanic crust (AOC) in the lithospheric mantle source and a part of the siliceous crust. The carbon isotopes for different minerals show that magma spent some time crystallizing in a magma chamber during which assimilation of crustal material occurred. Subduction-devolatilization of altered oceanic crust could be the best mechanism that transported large proportion of ASF (air-saturated fluid) and crustal components into the mantle source. The mantle plume existing beneath the Poyi intrusion could provide less contribution of real materials of silicate and fluid components.

scholarly journals Geochronological and Geochemical Constraints on the Formation of the Giant Zaozigou Au-Sb Deposit, West Qinling, China

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 37 ◽  
Author(s):  
Hao-Cheng Yu ◽  
Chang-An Guo ◽  
Kun-Feng Qiu ◽  
Duncan McIntire ◽  
Gui-Peng Jiang ◽  
...  
Keyword(s):  
Mineral Assemblage ◽  
Spatial Association ◽  
Massive Sulfide ◽  
Stage Model ◽  
Sulfide Mineralization ◽  
Low Oxygen ◽  
Ore Formation ◽  
West Qinling ◽  
T Values ◽  
Geochemical Constraints

The Zaozigou Au-Sb deposit has been controversial in its genesis and remains one of the most difficult ore systems to fully understand in West Qinling. The mineralization shows a broad spatial association with Triassic dikes and sills, which were previously thought to be genetically related to mineralization. Our U-Pb zircon dating in this contribution indicates that the ore-hosting porphyritic dacites were formed at 246.1 ± 5.2 Ma and 248.1 ± 3.8 Ma. The magmatic zircons yield εHf(t) values ranging from −12.5 to −8.9, with corresponding two-stage model ages of 2.08 to 1.83 Ga. The magma therefore could be derived from partial melting of Paleoproterozoic crustal materials. The ore-hosting porphyritic dacites have low oxygen fugacity, with ΔFMQ ranging from −4.61 to −2.56, indicating that magmas could have been sulfide-saturated during evolution in deep chambers and precluding the possibility that metals were released from the melt. Zaozigou exhibits characteristics widespread volcanics, massive sulfide mineralization, rare reduced mineral assemblage and discrete alteration zones which are not typical of reduced intrusion-related or porphyry gold systems. We propose that the spatially-related Triassic porphyritic dacite and dike swarm is not genetically related to the ore formation of Zaozigou Au-Sb deposit.

PGE geochemical constraints on the origin of the Ni-Cu-PGE sulfide mineralization in the Suoi Cun intrusion, Cao Bang province, Northeastern Vietnam

2014 ◽  
Vol 109 (2) ◽  
pp. 161-180 ◽  
Author(s):  
Tatyana V. Svetlitskaya ◽  
Nadezhda D. Tolstykh ◽  
Andrey E. Izokh ◽  
Phuong Ngo Thi
Keyword(s):  
Sulfide Mineralization ◽  
Geochemical Constraints
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