黑龙江晨明地区桦皮沟岩体和达里岱岩体LA-ICP-MS锆石U-Pb年龄及其意义

摘要

It was previously considered that Huapigou and Dalidai pluton pluton located in the Chenming area, Heilongjiang Prov⁃ince, respectively consist of Hercynian and Proterozoic granites. However, the authors defined the emplacement ages of Dalidai plu⁃ton and Huapigou pluton by LA-ICP-MS zircon U-Pb dating and obtained ages of 453.5±6.0Ma and 454.8±2.6Ma, which suggest that these granites are a part of Early Paleozoic granites located in the Yichun-Yanshou tectonic belt instead of the Hercynian and Proterozoic granites as previously believed.%前人认为，黑龙江省晨明地区的桦皮沟岩体(花岗质糜棱岩)和达里岱岩体(糜棱岩化黑云母花岗岩）分别由形成于元古宙和海西期的花岗岩组成。LA-ICP-MS锆石U-Pb测年对2个岩体的定年结果显示，桦皮沟岩体中的花岗质糜棱岩和达里岱岩体中的糜棱岩化黑云母花岗岩的206Pb/238U年龄加权平均值分别为453.5±6.0Ma和454.8±2.6Ma，表明二者均形成于早古生代，应是伊春—延寿构造带早古生代花岗岩带的组成部分，而非形成于元古宙和晚古生代。