Identification of an Early-Middle Jurassic oxidized magmatic belt, south Gangdese, Tibet, and geological implications

The south Gangdese region is the site of subduction of the Neo-Tethys and subsequent continental col- lision. Compared with widespread Cretaceous and Cenozoic magmatism, Early-Middle Jurassic magmatic rocks and related deposits are rarely reported, Our work identified a 〉200 km long felsic rock belt...

Full description

Saved in:
Bibliographic Details
Published in:Science bulletin (Beijing) 2017-06, Vol.62 (12), p.888-898
Main Authors: Zou, Yinqiao, Chen, Xilian, Huang, Wenting, Zhang, Jian, Liang, Huaying, Xu, Jifeng, Chen, Ling
Format: Article
Language:English
Subjects:
Early–Middle Jurassic igneous rock
Neo-Tethys subduction
Porphyry Cu deposit
The South Gangdese
Water-rich and oxidized magma
中侏罗世早期
地质意义
岩浆岩带
斑岩铜矿床
早期识别
氧化
西藏
锆石U-Pb年龄
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The south Gangdese region is the site of subduction of the Neo-Tethys and subsequent continental col- lision. Compared with widespread Cretaceous and Cenozoic magmatism, Early-Middle Jurassic magmatic rocks and related deposits are rarely reported, Our work identified a 〉200 km long felsic rock belt asso- ciated with Cu mineralization in the south Gangdese region. We report here zircon U-Pb ages, zircon Ce4＋/Ce3＋ values, and mineral assemblages of two Cu mineralized intrusions within the belt. A horn- blende granite and a diorite porphyry were emplaced at 177.3Ma and 166.3Ma, respectively. Geological occurrence and magmatic hematite-magnetite-chalcopyrite intergrowths suggest that Cu mineralization formed coeval with Jurassic intrusions. Mineralized intrusions have high zircon Ce4＋/ Ce3＋ and EuN/EuN ratios, and hematite-magnetite intergrowths, suggesting their parent magmas were highly oxidized, Hornblende is common and primary fluid inclusions are found in titanite and apatite, indicating their parent magmas were water-saturated and exsotved volatile phases at early stage of rnag- matic evolution. Those magma characters contribute to the formation of porphyry Cu deposits. Given that majority subduction-related porphyry Cu systems have been eroded following uplift and denudation, the well-preserved Early-Middle Jurassic cu mineralized igneous rocks in south Gangdese are favorable prospecting targets for subduction-related porphyry Cu deposits.
ISSN:2095-9273
DOI:10.1016/j.scib.2017.05.026