康定变质侵入岩的年代学及岩石地球化学特征  

Geochronological and Geochemical Characteristics of Kangding Metamorphosed Intrusions

作　　者：李志红[1,2] 罗照华[2] 陈岳龙[2] 赵俊香[2] 

机构地区：[1]国土资源部同位素地质重点实验室中国地质科学院地质研究所,北京100037 [2]中国地质大学地球与资源学院,北京100083

出　　处：《地球学报》2005年第B09期87-89,共3页Acta Geoscientica Sinica

基　　金：本文为国家自然科学基金项目（批准号：40173007,40234052）资助.

摘　　要：川西康定地区出露的变质侵入岩是以石英闪长岩、英云闪长岩和花岗闪长岩为主的中酸性岩浆岩。岩石中锆石主要结晶于721～773Ma，表明其形成于新元古代；岩体中所测最老年龄为2468Ma，可能代表扬子陆块的基底；在锆石的增生边及新生锆石颗粒获得的99～531M。年龄反映了后期变质事件的改造。该岩体的主量元素显示钙碱性分异趋势，微量元素呈现典型的岛弧环境地球化学特征，即相对富集大离子亲石元素、轻稀土元素，亏损高场强元素和的富集。以上的特征表踢，康定地区变质侵入岩在新元古代可能处于与俯冲有关的岩浆弧环境。The Kangding metamorphosed intrusions are mainly composed of quartz diorite-tonalite -granodiorite. The ages of igneous zircons from the complex range from 721 to 773 Ma, which shows the intrusive activity during Neoproteronoic. The oldest age obtained from the intrusions is 2 468 Ma, implying the involvement of materials from Yangtze craton basement. The ages of 99-531 Ma produced from zircon rims may reflect later metamorphic events. The complex shows a calc-alkaline differential trend in major elements, and the trace elements exhibit typical geochemical features of the island arc setting.

关 键 词：康定杂岩 变质侵入岩 新元古代 岩浆弧 岩石地球化学特征 康定地区 环境地球化学特征 年代学 中酸性岩浆岩 主量元素 

分 类 号：P588.14[天文地球—岩石学] P588.3[天文地球—地质学]