柴北缘孤山一带侵入岩U-Pb年代学约束及构造环境特征  

U-Pb geochronological constraints and tectonic environment characteristics of intrusive rocks in Gushan Area,north margin of Qaidam Basin

作　　者：马国杰[1] MA Guojie(Geological Survey of Gansu Province,Lanzhou 730000,Gansu,China)

机构地区：[1]甘肃省地质调查院,甘肃兰州730000

出　　处：《资源信息与工程》2024年第2期1-4,共4页Resource Information and Engineering

摘　　要：研究区位于祁连山脉南西部,岩体呈不规则的残块状、条带状混杂侵入于早元古代达肯大坂群中—深变质岩中,现已变质为中细粒二云花岗片麻岩。岩石中TiO_(2)质量分数为0.61%,Al_(2)O_(3)质量分数为12.5%,Na_(2)O和K_(2)O质量分数共7.43%,Fe_(2)O_(3)质量分数为0.94%,具有高Ti、Al、Fe和富钾的特征。锆石U-Pb加权平均值为766.1 Ma±5.4 Ma,侵位于新元古代南华纪。侵位方式为被动的岩墙扩张,为火山弧型花岗岩,形成于同碰撞构造环境,可能为I-S型花岗岩。The study area is located in the south and west Qilian Mountains.The rock mass is an irregular fragmentary and banded complex intruded into the middle and deep metamorphic rocks of the early Proterozoic Dakendaban Group,which transformed into middle and fine-grained bicloud granitic gneiss.TiO_(2)mass fraction is 0.61%,Al_(2)O_(3)mass fraction is 12.5%,Na_(2)O+K_(2)O mass fraction is 7.43%,Fe_(2)O_(3)mass fraction is 0.94%,with high Ti,Al,Fe,potassium-rich.The crystallization age of the rock mass is 766.1 Ma±5.4 Ma,and the intrusion is located in Neoproterozoic Nanhua Period.The emplacement pattern is passive dike expansive,volcanic arc type granite,formed in the co-collision tectonic environment,probably I-S type granite.

关 键 词：柴北缘 花岗岩 岩石地球化学 U-PB测年 

分 类 号：P588[天文地球—岩石学]