摘要
Objective The Tibetan Plateau is the largest continent-to-continent collision belt in the world. Two orogenic gold mineralisation belts have been recognized in this collision belt, which are as follows： the Indus-Yarlung Zangbo suture zone orogenic gold belt （IYOG）, represented by the Mayoumu and Bangbu gold deposits, and the Ailaoshan orogenic gold belt （AOG）, whose typical cases include the Zhenyuan and Chang＇an gold deposits. The IYOG formed during 54-45 Ma corresponds to the compressional deformation during the early stages of the collision of the plates of India and Eurasia, whereas the AOG formed in 38-29 Ma corresponds to that during the later stage of the collision. Recently, several medium- to large-sized gold deposits （e.g., the Dacha and Shangxu deposits） have been discovered along the Bangong Co-Nujiang suture belt, which indicates that another orogenic gold mineralisation belt existed within the Tibetan Plateau. However, the lack of a mineral suitable for dating or for altering the minerals that were affected by various tectonic thermal events causes difficulty to perform accurate dating. This study is based on the Shangxu gold deposit and analyses the genesis of zircon in gold-bearing quartz veins as well as the accurate gold-forming age by hydrothermal zircon micro probe analysis using the U-Pb （LA-ICP-MS） method.
Objective The Tibetan Plateau is the largest continent-to-continent collision belt in the world. Two orogenic gold mineralisation belts have been recognized in this collision belt, which are as follows： the Indus-Yarlung Zangbo suture zone orogenic gold belt （IYOG）, represented by the Mayoumu and Bangbu gold deposits, and the Ailaoshan orogenic gold belt （AOG）, whose typical cases include the Zhenyuan and Chang＇an gold deposits. The IYOG formed during 54-45 Ma corresponds to the compressional deformation during the early stages of the collision of the plates of India and Eurasia, whereas the AOG formed in 38-29 Ma corresponds to that during the later stage of the collision. Recently, several medium- to large-sized gold deposits （e.g., the Dacha and Shangxu deposits） have been discovered along the Bangong Co-Nujiang suture belt, which indicates that another orogenic gold mineralisation belt existed within the Tibetan Plateau. However, the lack of a mineral suitable for dating or for altering the minerals that were affected by various tectonic thermal events causes difficulty to perform accurate dating. This study is based on the Shangxu gold deposit and analyses the genesis of zircon in gold-bearing quartz veins as well as the accurate gold-forming age by hydrothermal zircon micro probe analysis using the U-Pb （LA-ICP-MS） method.
基金
financially supported by the National Key Research and Development Program of China(2016YFC0600308)
the China Geological Survey Project(DD20160015,DD20160026)
the National Science Foundation(41702080,41702086)
