柴北缘中酸性侵入岩成因及其构造意义  

Genesis and tectonic significance of medium-acid intrusive rocks in the northern margin of Qaidam Basin

作　　者：张炜[1] ZHANG Wei(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11-14,共4页Resource Information and Engineering

摘　　要：研究区位于柴北缘缝合带与磨拉石前陆盆地的结合部,区内构造经历了多期演化,岩浆岩广泛发育。岩体侵入于下元古界金水口岩群和寒武—奥陶纪滩间山群中,岩性为闪长岩、石英闪长岩、花岗闪长岩,属次铝质钙碱性岩系。岩石地球化学特征表明,该岩体具有火山弧花岗岩的特征,物源具有地壳和地幔的成分,并具同源岩浆演化特征。研究区主体属加里东期构造岩浆岩带,形成于板块碰撞前的构造环境,花岗岩结晶温压条件为640~720℃、0.1~0.3 GPa。The study area is located at the junction of the suture zone of the northern margin of Qaidam and the Molasse foreland basin.The structure in the area has undergone multiple stages of evolution and magmatic rocks developed extensively.The rock mass,composed of diorite,quartz diorite and granodiorite,belonging to the aluminouscalc-alkaline rock series,intruded into the Lower Proterozoic Jinshuikou rock group and the Cambian-Ordovician Tanjianshan Group.The geochemical characteristics showed that the rock mass had the characteristics of volcanic arc granite,its provenance has the composition of crust and mantle,with the characteristics of homologous magmatic evolution.The lithology is mainly a Caledonian tectonic magmatic belt,which formed in the tectonic environment before plate collision.The temperature and pressure conditions of granite crystallization are 640~720℃and 0.1~0.3 GPa.

关 键 词：柴北缘 中酸性侵入岩 成岩时期 构造环境 

分 类 号：P611[天文地球—矿床学]