U-Pb zircon geochronology, geochemistry and kinetics of the Huaniushan A-type granite in Northwest China |
| |
Authors: | Jiang Zhu Xinbiao Lü Xiaofeng Cao Yalong Mo Chao Chen |
| |
Institution: | 1. Faculty of Earth Resources, China University of Geosciences, Wuhan, 430074, China 2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China
|
| |
Abstract: | The Huaniushan granite is located at the Beishan orogenic belt, northwestern China. At the contact zone between the granite
and marble, a hydrothermal Pb-Zn and skarn Au deposit is formed. LA-ICP-MS zircon U-Pb dating yielded a weighted mean 206Pb/238U age of 229.5±2.6 Ma (MSDW=0.93) for the Huaniushan granite, implying its Late Triassic intrusion. Geochemistry analyses
show that the Huaniushan granite is enriched in Si, K, Na, and REE, and depleted in Mg and Ca, with contents of SiO2 (70.8% to 74.4%), Na2O+K2O (8.8% to 10.2%), CaO (0.93% to 1.44%), and MgO (0.14% to 0.48%). REE is characterized by obvious negative Eu anomaly. Rb,
Th, U, K, Pb, Nb, Zr and Hf elements are rich in the granite while Ba, Sr, P, Ti and Eu are deplete. The granite has a high
(Zr+Nb+Ce+Y) abundance and 104 Ga/Al ratios. Petrology, major and trace elements data all indicate that the Huaniushan granite is A-type granite which intruded
in a post-collisional extensional tectonic setting. The magma was dominantly sourced from partial melting of crustal intermediate-felsic
igneous rocks. Intensive magmatic activities and Au-Cu-Mo mineralization occurred throughout the Beishan orogenic belt during
the period from ca. 240 to 220 Ma. |
| |
Keywords: | A-type granite geochronology geochemistry tectonic setting Beishan orogenic belt |
本文献已被 CNKI SpringerLink 等数据库收录! |
|