皖南伏川晚元古代蛇绿岩套和休宁、许村、歙县晚元古代碰撞型花岗岩的发育,标志着该区晚元古代强烈的弧后造山构造-岩浆事件.本文所述复合岩墙群是该事件的最后一幕岩浆岩,由辉绿岩和花岗斑岩构成.对其组成和成因的研究,将有助于全面揭示该区晚元古代的岩浆活动规律.1 岩墙群的地质特征许村复合岩墙群出露于歙县许村镇至白蛇坑村一带(图1),平面上呈北东向展布,宽1.5～3km,延长约20km,它由近于平行排列的20余条岩墙组成.单个岩墙出露宽度2～7m,倾向135°～150°,倾角50°～70°.岩墙群切穿上元古界环沙组(Pt_3~h)的砂质 Late Paleoproterozoic ophiolites in the southern Wanfu River and the development of the Late Proterozoic collision granites in Xiuning, Xucun and Juxian marked the late Late Proterozoic arc-orogeny tectono-magmatic events in this area. The wall group is the last scene of the event, which is composed of diabase and granite porphyry, and the study on its composition and genesis will help reveal the law of the Late Proterozoic magmatism in the area.1 The dykes The Xucun composite dyke swarms are exposed in Xucun Town, Yixian County to Bai Shekengcun area (Figure 1). The plan is northerly distributed with a width of 1.5 ~ 3km and an extension of about 20km. It consists of nearly parallel arrangement With a width of 2 ~ 7m, a tendency of 135 ° ~ 150 ° and a dip angle of 50 ° ~ 70 °, and the dyke wall cut through the upper Proterozoic ring sand (Pt_3 ~ h) Sandy