目前对江南造山带新元古代构造演化存在不同认识.本文在系统收集近年来大量高精度年龄数据及岩石地球化学研究成果基础上,重塑了雪峰造山带(江南造山带西段)及其东南缘新元古代构造演化过程:880～820Ma期间雪峰造山带为岛弧岩浆作用阶段,东南缘城步地区为弧前盆地；820～ 810Ma期间雪峰造山带为弧-陆(主)碰撞阶段,城步地区处于弧前盆地向岛弧发展的过渡时期；810～800Ma期间雪峰造山带进入后碰撞环境,城步地区形成新的岛弧；800～ 630Ma整体进入裂谷盆地阶段.上述过程反映出扬子陆块东南缘的岛弧增生过程,同时暗示雪峰造山带南东面的雪峰期和南华纪沉积叠覆于华南残留洋盆之上.%The present paper deals, on the basis of abundant lithogeochemical and geochronologic data, with the reconstruction of the Neoproterozoic tectonic evolution in the Xuefeng orogenic zone and its southeastern margin. During 880-820 Ma, the Xuefeng orogenic zone was initiated in the stage of island-arc magmatism, and the Chengbu region on its southeastern margin appeared as a forearc basin. During 820-810 Ma, the Xuefeng orogenic zone experienced the stage of arc-continent collision, and the Chengbu region displays the transition from a forearc basin to an island arc. During 810-800 Ma, the Xuefeng orogenic zone went into the post-collision stage, and a new island arc came into being in the Chengbu region. Till 800-630 Ma, both the Xuefeng orogenic zone and its southeastern margin were developed into the rift basin without exception. The Neoproterozoic tectonic evolution outlined above suggests the island arc accretion on the southeastern margin of the Yangtze landmass, and overlapping of the Xuefengian and Nanhuan deposits upon the Huanan residual oceanic basin.
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