大型断裂带内发育的基性-超基性岩的岩石成因及侵位方式一直是地学研究的热点，它们可能是构造蛇绿混杂岩的组成部分，或是裂谷背景下幔源岩浆的产物。另外，基性-超基性岩易受到后期构造热事件的影响，能记录构造热事件发生的时间及温压条件，从而为探讨构造热事件的性质提供制约。政和-大埔断裂带内出露有大量基性-超基性岩，对其岩石成因、构造属性及后期经历的构造热事件的研究能更好地了解华夏板块大地构造演化。本申请项目拟对该断裂带内的基性-超基性岩进行详细的野外调查，通过岩相矿物学和Nd-Os同位素研究，明确其是否含有蛇绿岩套的组成部分，并进一步探讨其岩石成因及构造属性; 通过对基性-超基性岩中变质锆石和独居石U-Pb定年，结合锆石Hf-O同位素、微量元素研究，明确基性-超基性岩所记录的构造热事件的性质, 在此基础上开展华夏板块与冈瓦那陆块经历的泛非事件的对比研究，为华南板块与冈瓦那大陆的关系提供依据。

There have long been debated about the petrogenesis of the mafic-ultramafic rocks which generally occurred in large-scale fault zones. These rocks can represent the relics of an ophiolitic suite, or may be within plate igneous rocks which form in an intracontinental rift setting. On the other hand, mafic-ultramafic rocks can be affected by late tectonothermal events, thus they can record significant information on tectonic evolution. There are large amount of mafic-ultramafic rocks occurred in the Zhenghe-Dapu fault zone, Cathaysia Block. Studies on their petrogenesis, tectonic setting as well as late tectonothermal events these rocks experienced can offer better understanding of the tectonic evolution of Cathaysia Block. In this project, we propose to carry out a detailed geological and geochemical study of the mafic-ultramafic rocks in Zhenghe-Dapu fault zone. Through mineralogy, major and trace element studies as well as Nd-Os isotope analyses of the mafic-ultramafic rocks, we will elucidate whether they are the relics of an ophiolitic suite, which will help to understand their petrogenesis and tectonic affinity. Through zircon and monazite U-Pb dating and zircon Hf-O isotopes and trace element analyses, we will constrain the nature of the tectonothermal events which these rocks experienced. When considered in the context of Pan-African Orogeny of Gondwanaland, the nature of the tectonothermal events will led to significant implications for the relationship between South China Block and Gondwana supercontinent.