临沧花岗岩基中晚三叠世侵入岩特征及构造环境

THE FEATURE AND TECTONIC ENVIRONMENT OF LATE T INTRUSION ROCK IN LINCANG GRANITE BATHOLITE

通过对滇西云县地区临沧花岗岩基的黑云二长花岗岩体的年代地质学、岩石学和地球化学开展了较系统的研究,获取的若干件单颗锆石U-Pb同位素年龄值都集中在210Ma左右,说明该地区的黑云二长花岗岩浆主要活动时间为晚三叠世。并对晚三叠世花岗岩按岩石学特征及其侵位先后顺序,划分为七种不同类型的侵入体。根据临沧花岗岩基晚三叠世侵入岩岩石地球化学特征,确定这些花岗岩主要为印支晚期同碰撞"S"型花岗岩。

According to the systematic study of age geology,petrology and geochemistry of Lincang granite batholite biotite adamellite in Yunxian area,W Yunnan,the isotopic age of many monomineralic zircons concentrates on 210 Ma or so,showing the main activity time of biotite adamellite magma in this area is Late T. The Late T granite can be divided into 7 different types of intrusion bodies according to the lithological character and emplacement order. Based upon the geochemical feature of Late T intrusion rock in Lincang granite batholite,we think it is mainly the Late Indosinian co-collision ＂S＂type granite.