Multi-scale rheology and strain localization of the continental lithosphere

大陆岩石圈的多尺度流变学和应变定位

• 批准号: 157155817
• 负责人: Dr. Christoph Schrank
• 金额: --
• 依托单位: Queensland University of Technology (QUT)
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/157155817?language=en
• 关键词: Multi; scale; rheology; strain; localization

Mechanical flow properties (i.e., rock rheologies) control the deformation of rocks and are therefore of utmost importance for the general understanding of plate tectonics, mountain building, earthquakes, and structural mineral, oil, and gas deposits. However, little is known about rheology on dm- to 10km scales although these scales are of highest relevance for economic and environmental geology. This project intends to fill this gap with an innovative experimental approach that reconciles laboratory deformation experiments and geological field data with thermal-mechanical multi-scale numerical experiments. The fundamental uncertainty regarding rock rheology on intermediate scales exists because constraints for rheology mainly stem from mm- to cm-scale laboratory deformation experiments or from the inversion of large-scale geophysical and geodetic observations (10-100km scale). Both cannot be easily extrapolated to intermediate length scales because rheology is scale-dependent and highly dynamic over geological time and length scales. The physical complexity of this problem does not permit theoretical solutions. Therefore, an innovative numerical approach calibrated with laboratory and natural data is proposed that employs a new thermodynamically consistent multi-scaling method. Three main outcomes are expected from this project: 1) Flow laws of rock masses are obtained from dm- to km scale. 2) Quantitative laws describing how rock rheology evolves with scale are determined, connecting small-scale laboratory experiments with largescale geophysics and geodetics. 3) The physical scaling lengths governing shear localization on dm- to km scales under geological conditions are identified.

机械流动性能（即，岩石流变学控制着岩石的变形，因此对于板块构造、造山运动、地震和构造矿物、石油和天然气矿床的一般理解至关重要。然而，鲜为人知的是，流变学的dm-10公里尺度，虽然这些尺度是最高的经济和环境地质的相关性。该项目旨在通过一种创新的实验方法来填补这一空白，该方法将实验室变形实验和地质现场数据与热机械多尺度数值实验相协调。关于中等尺度岩石流变学的基本不确定性存在，因为流变学的约束主要来自毫米至厘米尺度的实验室变形实验或来自大尺度地球物理和大地测量观测（10- 100公里尺度）的反演。两者都不能很容易地外推到中间长度尺度，因为流变学是尺度依赖性的，并且在地质时间和长度尺度上是高度动态的。这个问题的物理复杂性不允许理论上的解决方案。因此，提出了一种创新的数值方法校准实验室和自然数据，采用一种新的物理一致的多尺度方法。本研究主要取得以下成果：1）获得了dm-至km尺度的岩体流动规律。2)描述岩石流变学如何随尺度演变的定量规律是确定的，将小规模的实验室实验与大规模的地球物理学和大地测量学联系起来。3)确定了地质条件下dm-km尺度上剪切局部化的物理标度长度。