班公湖-怒江结合带北侧陆缘火山-岩浆弧带的厘定及其意义

在班公湖-怒江结合带西段北侧的拉热拉新岩体东、西两侧,新发现了一些早白垩世岩体、相伴的陆缘火山岩组合和矿(化)点,侵入岩和火山岩的岩石化学特征均显示其成因与中特提斯洋向北俯冲消减密切相关。本文将班-怒带北侧的火山-侵入岩带厘定为五峰尖-拉热拉新晚侏罗世—早白垩世陆缘火山-岩浆弧带,同时讨论了陆缘火山-岩浆弧带的厘定在分析中特提斯构造演化方面的研究意义。

The delineation and significance of the continental-margin volcanic-magmatic arc zone in the northern part of the Bangong-Nujiang suture zone

The Wufengjian-Larelaxin volcanic-magmatic zone composed of the Late Jurassic volcanic rocks and Early Cretaceous intermediate-acidic intrusive rocks ((Larelaxin and Changlonghe superunits) is aligned in the northern part of the Bangong-Nujiang suture zone. The volcanic rocks and early (quartz) diorite and granodiorite (Tangzha-Nalielong and Fenghuoshan units) are assigned to the magmatic arc granites generated from the northward subduction and collision of the Meso-Tethyan Ocean and South Qiangtang block during the Late Jurassic to the Early Cretaceous, whereas the late granites (Aiyongco-Songmo unit) belong to the post-orogenic granites formed posterior to the northward subduction and collision cited above.