Compositional Variation of Amphiboles During Magma Mixing: A Case Study of Huangyangshan A-Type Granite in Kalamaili Metallogenic Belt, East Junggar, China

Frontiers in Earth Science

卷:9

Chenyang Ye²  Yonggang Feng³  Ruxiong Lei³  Gaoxue Yang³ 

[1] College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China;

[2] Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China;

[3] Laboratory of Mineralization and Dynamics, Chang’an University, Xi’an, China;

[4] School of Earth Science and Resources, Chang’an University, Xi’an, China;

[5] State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China;

关键词: amphibole;    A-type granite;    dioritic enclave;    magma mixing;    Sn mineralization;    Huangyangshan;   

DOI  :  10.3389/feart.2021.650014

来源: DOAJ

【 摘 要 】

The Huangyangshan A-type granitic pluton, distributed along the thrust fault in the Kalamaili region of East Junggar, Xinjiang, China, consists of alkaline granite containing abundant dioritic enclaves that formed via magma mixing. Both the host granite and the enclaves contain sodic amphiboles. The textural evidence indicates that amphiboles crystallized as a magmatic phase in both units. We determined major and trace element contents of amphiboles from both units to investigate the compositional variation of the amphiboles during the magma mixing process. The results show that cations of W- and C-site are influenced by chemical compositions of the magma whereas cations of A-, B- and T-site and Al3+ are controlled by crystal structure. Therefore, the variations of W- and C-site cations can reflect magma evolution. The core and rim of the amphiboles show similar trace element patterns, which also suggests that the amphiboles are late-stage phases. Furthermore, the amphibole-only thermometers yield reasonable estimates that are consistent with petrographic evidence. However, thermometers based on partition coefficients and all the currently available amphibole-based barometers that rely on Al contents or DAl cannot be applied to Fe-rich and Al-poor amphiboles.

【 授权许可】

Unknown