秦岭杂岩的研究- - 以灰池子、牛角山和漂池岩体围岩为例

秦岭造山带是研究造山带的形成过程及大陆增生地球动力学机制的天然实验室。然而作为秦岭造山带重要组成部分的秦岭杂岩，其形成时代、构造背景和前寒武纪的构造归属等问题仍存在较大分歧。本项目拟选择北秦岭地体豫西灰池子、漂池和牛角山岩体（秦岭杂岩中的最老侵入岩体，年龄为~960 Ma）的围岩- - 秦岭杂岩为研究对象，对其中的变质沉积岩和变质基性岩（尤其是高MgO玄武岩）进行详细的野外地质、岩石学、地球化学、年代学、全岩Sr-Nd同位素和原位锆石Hf同位素研究，综合限定秦岭杂岩的形成时代及构造环境；利用邻区华北南缘和扬子北缘已发表的年龄和同位素资料进行综合对比研究，为秦岭杂岩中变沉积岩的物源区及前寒武纪的构造归属提供重要信息；结合区域地质资料，最终探讨北秦岭前寒武纪的演化历史及对造山带演化的响应。

The Qinling orogenic belt (QOB) is a natural laboratory for studying the formation process of the orogenic belt and geodynamic mechanism of continental accretion. However, the Qinling complex, as an important part of the QOB, its formation age, tectonic setting and tectonic attribution in Precambrian remain controversial. We plan to present detailed field geology, petrology, geochemistry, geochronology, Sr-Nd isotopes of the bulk rock and in-situ zircon Lu-Hf isotopes for the meta-sedimentary rocks and meta-basites (especially the high-MgO basalts) around Huichizi, Piaochi and Niujiaoshan (the oldest granite intruding into the Qinling complex with the age of ~960 Ma) granites in the North Qinling terrain (NQT) to constrain the timing of formation and tectonic setting of the Qinling complex. In conjunction with the present age and isotopic data from the southern North China Craton and northern Yangtze Craton will provide important information for the sources and tectonic affinities in Precambrian of the meta-sedimentary rocks from the Qinling complex. Moreover, the above research combined with regional geological data, this project intends to study the evolution history of the NQT in Precambrian and its response for the evolution of the orogenic belt.