Fission-track-dating at drill cores from the ICDP/CCSD Donghai drill holes, China

该项目的总体目标是量化苏鲁超高压带的热构造历史。国际地球科学中心/国际地球科学委员会的预导孔(Pp1；PP2)和东海的国际地球科学中心/国际地球科学中心的主要钻孔--中国，是能够利用裂变径迹热年代学连续重建中低温历史(低于300C)的关键孔。岩石学和构造数据的结合将允许将FT-T-T路径转换为造山后的折返/隆升历史。与高温地质年代学的结合将把热构造历史延伸到造山过程。在中国中东部的秦岭-大别-苏鲁造山带数据库中对比、整合这些年代学数据，并用于完善现代热构造模式。我们是德国ICDP-项目中唯一能够获得ICDP/CCSD东海钻孔样品的研究小组。此外，还将利用钻孔样品进一步改进标准裂变径迹测年技术。一个样品的颗粒的铀含量变化很大，需要改进颗粒安装和检测云母之间自动切换的重复性。此外，对大量受限轨道长度的精确测量，即使在低含铀磷灰石中，也将允许更好地约束T-T模型。

The general aim of the project is to quantify the thermo-tectonic history of the Sulu UHP belt. The ICDP/CCSD-pre-pilot holes (PP1; PP2) and the main ICDP/CCSD-drill hole at Donghai, China, are keyholes that allow the continuous reconstruction of the medium to low temperature history (less than 300 °C) by applying fission-track thermochronology. Integration of petrologic and structural data will permit transferring the FT-T-t paths into a post-orogenic exhumation/uplift history. The combination with high temperature geochronometers will extend the thermotectonic history to the orogenic process. The thermochronological data will be compared, integrated in the database of the Qinling-Dabie-Sulu orogen, East-Central China and used to refine the recent thermo-tectonic models. We are the only research group in the German ICDP-program that have access to samples from the ICDP/CCSD Donghai drill holes. In addition, the samples of the drill holes will be used to improve further the standard fission track dating technique. Strong variations in the uranium content of grains from one sample need an improvement of the reproducibility of the automated switching between grain mount and detection mica. Furthermore, the precise measurement of a large number of confined track length, even in low uranium bearing apatites, will allow to better constraint the T-t models.