39Ar/40Ar in situ determination on local equilibrium domains: Exhumation history of UHP rock from the Chineese Continental Scientific Drilling (CCSD) drill hole in Donghai, China

局部平衡域的 39Ar/40Ar 原位测定：中国东海大陆科学钻探 (CCSD) 钻孔中超高压岩石的折返历史

• 批准号: 22218140
• 负责人: Professor Dr. Roland Oberhänsli
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/22218140?language=en
• 关键词: 39Ar; 40Ar; situ; determination; local

The goal of this proposal is a more detailed definition of the retrogressive exhumation paths. Petrographic and petrologic investigations allow defining locally well preserved equilibria in shear bands. In situ 39Ar/40Ar dating of amphiboles and micas from these locally preserved equilibria in shear band from the Donghai main drill hole allows to better constrain the exhumation history of the UHP rocks from the Dabie - Sulu UHP belt. In the Donghai drill hole preliminary fission track work by Glasmacher and Wagner show juxtaposition of of several units along shear bands and shear zones. Apatite fission track ages on either side of these shear bands are reported as 30/50 Ma and 80/50 Ma. It is obvious that within the major shear zone described in from the Donghai main hole, shear bands of varying ages exist and that investigations of such petrologically and structurally discrete zones add to the understanding of the exhumation history. The exhumation history of the UHP crust in the Sulu belt is jet not well constrained. We got fresh samples from the drill hole. Furthermore, we think that in the core we can observe geometric constraints of deformation and crystallisation.

这项提案的目标是对倒退挖掘遗骸的路径作出更详细的定义。岩石学和岩石学研究可以确定剪切带中局部保存完好的平衡。通过对东海主孔剪切带局部保存的角闪石和云母进行~(39)Ar/~(40)Ar原位测年，可以更好地约束大别-苏鲁超高压带超高压岩石的折返历史。在东海钻孔中，Glasmacher和Wagner的初步裂变径迹工作显示了沿剪切带和剪切带的几个单元的并置。这些剪切带两侧的磷灰石裂变径迹年龄分别为30/50 Ma和80/50 Ma。显然，在东海主孔描述的主要剪切带内，存在不同时代的剪切带，对这些岩石学和构造离散带的研究有助于加深对折返历史的理解。苏鲁带超高压地壳的折返历史是喷流不受约束的。我们从钻孔里拿到了新的样本。此外，我们认为，在核心，我们可以观察到变形和结晶的几何约束。