Collaborative Research: Subduction and Exhumation of Ultrahigh-pressure Rocks: Field and Drilling Petrotectonic Studies in Eastern China

本项目将继续对在研究中国超高压地体过程中获得的钻芯和露头样品进行地球化学和年代学分析。位于苏鲁地体东海地区的中国大陆钻探项目(CCSD)为从三维角度研究这一重要地带提供了独特的机会。钻探工作刚刚结束，完成了几个浅孔和一个5公里深的钻孔。大别-苏鲁带的野外研究和钻孔样品的初步研究为大陆物质俯冲和折返过程以及高P-低T变质过程提供了许多新的见解，目前是地球科学中的一个热门话题。具体地说，大别-苏鲁缝合带似乎是世界上处理地壳岩石被带到100多公里深处然后返回地表的条件的最佳地点之一，以及200公里深处的地幔岩石如何被输送到浅层并并入俯冲大陆板块或山带的问题。该项目是PI与在钻探中发挥重要作用的中国同事长期合作的延续。美国的主要作用包括钻芯样本的详细矿物学研究。

0506901LiouThis project will continue geochemical and chronological analyses of drill core and outcrop samples obtained in the course of studying an ultrahigh-pressure (UHP) terrane in China. The Chinese Continental Drilling Project (CCSD), in the Donghai area of the Sulu terrane, provides a unique opportunity to study this important belt in three dimensions. The drilling is just now winding up with the completion of several shallow holes and one 5-km deep borehole. Field studies of the Dabie-Sulu belt and the initial studies of borehole samples have provided many new insights into the processes involved in the subduction and exhumation of continental material and into the processes of high P - low T metamorphism; presently a "hot topic" in earth sciences. Specifically, the Dabie-Sulu suture zone appears to be one of the best places in the world to address the conditions under which crustal rocks are taken to depths of more than 100 km and then returned to the surface, as well as the question of how mantle rocks from depths of 200 km are transported to shallow depths and incorporated into subducted continental slabs or mountain belts. The project is the continuation of the PI's long term collaborations with Chinese colleagues who have played a major role in the drilling. The major US role involves detailed mineralogical studies of drill core samples.