鲁西蒙山龟蒙顶、云蒙峰岩体的锆石 SHRIMP U-Pb测年及形成时代

SHRIMP U-Pb Age Dating and the Formation Age of Zircon in Guimengding Rock and Yunmengshan Rock in Mengshan Area of Luxi

摘要:

蒙山主峰龟蒙顶为片麻状花岗闪长岩，原划为新太古代早期侵入岩。根据新测的2件样品锆石SHRIMP U-Pb年龄分别为（2539±17）Ma，（2544±15）Ma，其形成时代确定为新太古代晚期。蒙山北部云蒙峰为中粒二长花岗岩，锆石SHRIMP U-Pb年龄为（2534±8）Ma，其侵入龟蒙顶岩体片麻状花岗闪长岩。龟蒙顶岩体属峄山岩套TTG质花岗岩，是地幔岩浆侵入混入地壳物质形成的。云蒙峰岩体属傲徕山岩套二长花岗岩，为上地壳物质重熔（深熔）作用形成。

Abstract:

Guimengding is the main peak of Mengshan mountain. Its rock property is gneissic granodiorite. According to newly dating results of two samples, their zircon SHRIMP U-Pb ages are（2539±17）Ma and（ 2544±15）Ma seperately. It was formed in the late period of Neoarchean. Yunmengfeng in north part of Mengshan mountain is particles monzogranite. Its zircon SHRIMP U-Pb age is （2534±8）Ma, while its intrusive rock is gneissic granodiorite. Guimengding rock belongs to TTG granite in Yishan rock set. It was formed by mantle magma and intruded by crustal magma. Yunmengfeng rock belongs to monzogranite rock in Aolaishan rock set. It was formed by deep penetration at the upper part of the crust.