华南大地构造基本特点及其对原生金刚石的制约作用

Characteristics of the Geotectonics in South China and Their Restrictions on Primary Dlamond Deposits

亚洲大陆是世界上研究大陆动力学的最佳场所之一 ,其中华南板块的构造格局与太平洋板块和印度板块的共同作用关。华南板块中 ,由于绍兴—鹰潭—藤县—北海断裂带内中元古代蛇绿混杂岩的确认并恢复为消减的大洋 ,其两侧古老的扬子地块和华夏地块及其演化历史的追溯也日见清晰。它们是在两个克拉通地块基础上发展起来的。包超民等1998年在浙江省龙游首次发现的原生金刚石 ,产于这条深断裂旁侧白垩纪盆地中的似金伯利岩岩管内 ,含矿岩管生成深度大 ,构造部位有利 ;金刚石呈八面体外形、纯度高 ;类似的岩管有100多个 ,但研究程度较低 ,因而具有良好的找矿前景。

The Asia continent is one of the best places in the world to study the continental dynamics,in which the tectonic framework of Huanan(south China)plate is related to the activities of Pacific plate and Indian plate since Mesozoic. In the Huanan plate,the ophiolitic melange of middle Proterozoic in Shaoxing_Yingtan_Tengxian_Beihai fault zone was confirmed to be subducting ocean,the evolution of the Yangtze block and Huaxia block,which are located at both sides of the fault zone ,become clearer and clearer.The primary diamond deposit,which was first found by Mr.Bao Chao-min and his colleagues in 1998 in Longyou County of Zhejiang Province,was originated from the kimberlitoid pipes.The pipes are located in the Cretaceous basin beside this deep fault and the diamond_bearing pipe was deeply formed within a favorable geological structure.The diamond occurs in octahedral crystal without visual impurities.There are more than 100 similar pipes in the area,which are ,so far,poorly studied.It should has great prospects for diamond in this area.