Zircon U-Pb Dating and Geochemistry of the Luchun Volcanic Rocks, and Its Geological Implications in the Luchun Cu-Pb-Zn Deposit, Yunnan, China
摘要
The Luchun Cu-Pb-Zn deposit in the Jinshajiang-Lancangjiang-Nujiang region in China is spatially associated with the Luchun volcanic rocks. Zircon U-Pb dating shows the volcanic rocks formed at 270.0±4.6Ma. Rare earth and trace element distribution patterns display typical island arc signatures highlighted by the conjunction of LREE-enrichment with troughs at Na, Ta, and Ti, suggesting the Luchun volcanic rocks are related to the island arc setting, which was triggered by the westward subduction of the Jinshajiang Oceanic plate in the late Early Permain. The ores of the Luchun Cu-Pb-Zn deposit owned the sedimentary characteristics of the banded and bedded structure; the immobile elements ratios of the ores are close to the Luchun volcanic rocks, indicates the Luchun Cu-Pb-Zn deposit was formed by a process of the volcanic exhalative and sedimentary mineralization in the Hercynian.