相山地区变质基底新认识及其原岩归属的对比研究  

NEW RECOGNITION ON THE METAMORPHIC BASEMENT IN XIANGSHAN AREA AND THE COMPARATIVE STUDY ON ATTRIBUTION OF ITS ORIGINAL ROCKS

作　　者：章邦桐[1] 胡恭任[1] 王湘云[1] 陈培荣[1] 倪琦生[1] 

机构地区：[1]南京大学地球科学系

出　　处：《铀矿地质》1997年第1期1-7,共7页Uranium Geology

基　　金：国家教委博士点专项基金;核工业地质总局"八五"课题联合资助

摘　　要：在相山北部首次发现十字石片岩及堇青石片岩。根据随变质作用增强而出现的新变质矿物，将相山变质岩基底划分为绢云母千枚岩带、黑云母片岩带、铁铝榴石片岩带和十字石片岩带。获得相山地区黑云母片岩－十字石片岩的Ｒｂ－Ｓｒ等时线年龄值为７１９Ｍａ，斜长角闪片岩的Ｒｂ－Ｓｒ等时线年龄值为７２６．６Ｍａ，表明相山基底变质岩属新元古期变质岩而不是加里东期变质岩。提出并采用微量元素地球化学比值聚类分析方法，确认相山地区变质岩原岩不属震旦系，而与华夏地块（古陆）的陈蔡群相当。The staurolite schist and cordierite schist have been discovered in northern Xiangshan area for the first time. According to the appearance of typical metamorphic minerals with the increase of metamorphic degree, metamorphic rocks in Xiangshan area can be divided into four metamorphic zones: sericite phyllite zone, biotite schist zone, almandite schist zone and staurolite schist zone. The Rb-Sr isochron ages of 719 Ma and 726. 6 Ma obtained respectively from biotite schist-staurolite schist and plagioclase-hornblende schist indicate that basement metamorphic rocks in Xiangshan area must be attributed to Neoproterozoic rather than Caledonian. On the basis of comparative study and cluster analysis of trace element ratio it is confirmed that the original rocks of Xiangshan metamorphic basement do not belong to Sinian,but may be corresponding to Chencai Group in Huaxia terrane.

关 键 词：铀矿床 变质基底 原岩归属 相山地区 

分 类 号：P619.140.2[天文地球—矿床学]