Petrogenesis of the devonian high-Mg rock association and its tectonic implication for the Chinese Altai orogenic belt, NW China

2014 ◽  
Author(s):  
Yulin He
Keyword(s):  
Orogenic Belt ◽  
Tectonic Implication ◽  
Nw China ◽  
Rock Association

Petrogenesis of the Devonian high-Mg rock association and its tectonic implication for the Chinese Altai orogenic belt, NW China

2015 ◽  
Vol 113 ◽  
pp. 61-74 ◽  
Author(s):  
Yulin He ◽  
Min Sun ◽  
Keda Cai ◽  
Wenjiao Xiao ◽  
Guochun Zhao ◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Tectonic Implication ◽  
Nw China ◽  
Rock Association

scholarly journals Petrogenesis and Tectonic Significance of the ~276 Ma Baixintan Ni-Cu Ore-Bearing Mafic-Ultramafic Intrusion in the Eastern Tianshan Orogenic Belt, NW China

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 348
Author(s):  
Minxin You ◽  
Wenyuan Li ◽  
Houmin Li ◽  
Zhaowei Zhang ◽  
Xin Li
Keyword(s):  
Orogenic Belt ◽  
Olivine Gabbro ◽  
Early Permian ◽  
Eastern Tianshan ◽  
Nw China ◽  
Tianshan Orogenic Belt ◽  
Tectonic Significance ◽  
Ultramafic Intrusion ◽  
Back Arc ◽  
Duke Island

The Baixintan mafic-ultramafic intrusion in the Dananhu-Tousuquan arc of the Eastern Tianshan orogenic belt is composed of lherzolite, olivine gabbro, and gabbro. Olivine gabbros contain zircon grains with a U-Pb age of 276.8 ± 1.1 Ma, similar to the ages of other Early Permian Ni-Cu ore-bearing intrusions in the region. The alkaline-silica diagrams, AFM diagram, together with the Ni/Cu-Pd/Ir diagram, indicate that the parental magmas for the Baixintan intrusion were likely high-Mg tholeiitic basaltic in composition. The Cu/Pd ratios, the relatively depleted PGEs and the correlations between them demonstrate that the parental magmas had already experienced sulfide segregation. The lower CaO content in pyroxenites compared with the Duke Island Alaskan-type intrusion and the composition of spinels imply that Baixintan is not an Alaskan-type intrusion. By comparing the Baixintan intrusion with other specific mafic-ultramafic intrusions, this paper considers that the mantle source of the Baixintan intrusion is metasomatized by subduction slab-derived fluids’ components, which gives rise to the negative anomalies of Nb, Ti, and Ta elements. Nb/Yb-Th/Yb, Nb/Yb-TiO2/Yb, and ThN-NbN plots show that the Baixintan intrusion was emplaced in a back-arc spreading environment and may be related to a mantle plume.

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