Jiangmiao intrusion is mainly composed of gabbro and diorite, and minority of monzonite. It belongs to the latest episode of Mesozoic magmatism in the Milddle-Lower Yangtze region, with its LA-ICP-MS zircon U-Pb age of 118 ± 1. 1Ma. There is no significant crustal contamination during magma ascending and crystallization by petrochemical analysis. The εNd(t) values of Jiangmiao intrusion range from -0. 49 to -2. 29, situated in the field between the DMM and EM II end-members in the εNd(t) vs. ( 87Sr/86Sr), diagram, and the simple binary mixing calculation indicates that its magma source contains a large proportion of materials from the depleted asthenosphere. Integration with previous age data, the Mesozoic magmatism in the Middle-Lower Yangtze region can be divided into three episodes ; Early (151 - 133Ma) , middle ( 131 - 126Ma) and late ( 125 - 118Ma) episodes. This region was under intraplate extensional environment in Mesozoic and experienced a series of processes of lithospheric extension and asthenosphere upwelling.
|Number of pages||12|
|Journal||Acta Petrologica Sinica|
|Publication status||Published - 2010|
- Asthenosphere upwelling
- Middle-Lower yangtze region
- Zircon U-Pb dating