华夏造山带基底年代学研究的评析

自八十年代初作者提供第一批测年数据论证“华夏古陆”以来，国内许多学者又在近十年相继深入的探索，取得了更为丰富的资料。诸如闽北、粤西、海南元古基底的存在业已确证；同时也在更大的范围内有了新的重要发现，如上虞—政和—莲花山断裂系以东的中生代火山岩覆盖区大量露头已被揭示属于早、中元古代的基底，其地域甚广且波及东海陆架区。近年，对中生代火山岩及古生代侵入岩所作的稳定同位素研究成果再次证实源于古结晶基底的重熔。并测定东南广大火山岩覆盖区基底T（DM）普遍为1400～2000Ma，个别点达2750Ma。对近年来大量涌现的年代学资料必须予以审慎甄别和评价。如浙江陈蔡地区所谓“晚元古代”地层的厘定则是完全忽视了强动力作用的构造地球化学效应。

PROGRESSES AND PROBLEM OF THE BASEMENT CHRONOLOGICAL RESEARCH ON THE CATHAYSIA OROGENIC ZONE

In the beginnin of 1980's, the author proposed the first chronological data discussing the paleo-Catheysia continent. Since then, many domestic scholars have made further research in the last decade and have obtained more informtion proving the existence of Proterozoic basement in the north of Fujian, the west of Guanxi and Hainan, Meanwhile, some imporiant discoveries were found in a larger range of area. For example, the volcanic covering area of the Mesozoic Era to the east of the Shangyu-Zhenghe- Lianhua fault system was provec to be the basement exposure of the Lower and Middle Proterozoic Suberathem. The area reaches out to the Eastern ocean continental shelf. It was also proved by the stable isotope study that the volcanic rock of the Mesozoic Era and the intrusive rock of the Palaeozoic Era are the remeliting of Paleocrystalized basement. It was also determined that the basement T (DM) of the volcanic covering area in the southeast area is generally between 1400~2000Ma, With few points over 2750Ma.Careful discrimination and evaluation should be made upon the chronological information emerged in a large amout in recent years. For example, the determination of the so-callde "upper Proterozoic stratum" in the Chencai Area in Zhejiang completely overlooked the tectonic geochemical effect with strong dynamic funtion.