遂昌麻车─后山垵糜棱岩的发现及其意义

THE DISCOVERY OF MACHE-HOUSHAN' AN MYLOITE IN SHUICHANG AND ITS SIGNIFICANCE

作者在野外工作中，于遂昌─大柘变质岩断块（下称遂昌变质岩断块）北西侧，麻车─后山垵等地的地表或探矿巷道内，相继发现了多处糜棱岩化岩石露头，认为这一带存在一条较大的韧性剪切带。经对该带的地质，地球化学及金银矿分布的特征的综合分析研究，指出该韧性剪切带有关的金银矿化活动可分为两个期次，即早期金在韧性剪切活动中初始富集，晚期的脆性变形在局部地段形成金矿体。提出在该韧性剪切带找矿工作中，应重视继承韧性剪切带的脆性断裂和断裂带内的浅色蚀变组合及矿化特征。

Some mylonite has been discovered in Mache to Houshan' an in the northwest of Suichang metamorphic rock fault block. They occur in the same ductile shear zone. Beside this ductile shear zone, about 14 gold (silver) mineral occurrences or/and mineralized points have been discovered. Having studied the geological and geochemical characters of the ductile shear zone and the gold ore bodys, we found that the ore's reservolr structures and source of material were relat ed with ductile shear movement. The deep ductile shear movement made the Au element remobilized, imnigrated and inifially enriched in the brittle space.The structure zone continues moving along with the swelling up of the fault block, which caused the rock brittle de formed and turned the Au element into the ore body in parst of space. So to look for the (gold) mine in ductile shear zone, one must first pay attention to the successive brittle fault. And special attention must be paid to the decolourization of wallrock and its mineralized charater.