云南鲁春铜铅锌矿床鲁春火山岩锆石U-Pb年龄、地球化学及其地质意义

Zircon U-Pb dating and geochemistry of the Luchun volcanic rocks,and its geological implications in the Luchun Cu-Pb-Zn Deposit, Yunnan, China

位于三江地区的云南鲁春铜铅锌矿床和鲁春火山岩有密切的关系。鲁春火山岩锆石U-Pb年龄为270.0±4.6Ma。稀土和微量元素分布图显示该火山岩相对富集轻稀土元素、强烈亏损Na、Ta、和Ti,表明该火山岩具有岛弧火山岩的地球化学特点,反映了该火山岩形成于早二叠世晚期金沙江洋盆消减阶段的岛弧构造环境。鲁春铜铅锌矿床矿石具有条带状、层状构造等沉积作用的特点;矿石的不活泼元素比值和矿区火山岩相近,表明鲁春铜铅锌矿床经历了海西期火山喷流沉积成矿作用。

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.