A stress inversion method requiring only fault slip sense
A stress inversion method requiring only fault slip sense
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一种仅需要断层滑动感知的应力反演方法
DOI：
10.1029/2000jb900353
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发表时间：
2001
影响因子：
--
通讯作者：
L. Arlegui
中科院分区：
文献类型：
--
作者：
R. Lisle;T. Orife;L. Arlegui
在许多情况下，由于缺乏指示断层上滑动方向的构造，使用断层滑动数据进行古应力反演的标准方法受到阻碍。然而，在这种情况下，平面标记物的偏移量，例如底墙和悬壁中匹配的床层，通常允许观察到倾角分离的感觉(正向或反向)。在这种位移标志是水平的，或者至少在它们的分界线是水平的地方，很容易证明，净滑动的倾滑分量的意义与倾角分离的意义是相同的。探索了从由一组断层的方向组成的数据中表征应力张量的方法，每一组断层都具有已知的倾滑意义(正向或反向)。根据应力二次曲线的性质，发现了倾滑方向、断层面方向和应力张量之间的关系。该关系被用作应力反演的网格搜索法的基础，在该方法中，系统地考虑了大量不同方向和形状的应力张量。那些成功地解释了观测到的断层上的偏移量意义的张量被认为是古应力问题的潜在解决方案。文中给出了新应力反演方法的不同应用实例，包括对钻孔断层数据的分析。这些例子说明了新方法潜在地拓宽了古应力分析的范围。
In numerous cases, the use of standard methods of palaeostress inversion from fault slip data is prevented by the absence of structures that indicate the direction of slip on the fault. In such instances, however, the offset of planar markers, such as beds matched in the footwall and hanging wall, often allows the sense of dip separation (normal or reverse) to be observed. Where such displaced markers are horizontal or at least where their cut off lines are horizontal, it can be readily demonstrated that the sense of the dip-slip component of net slip is the same as the sense of dip separation. Ways are explored for characterizing the stress tensor from data consisting of the orientations of a collection of faults, each with known dip-slip sense (normal or reverse). On the basis of properties of the stress quadric the relationship between dip-slip sense, fault plane orientation, and the stress tensor is discovered. This relationship is used as the basis of a grid search method of stress inversion, in which a large number of stress tensors differing in orientation and shape are systematically considered. Those tensors that successfully explain the senses of offset on the observed faults are considered potential solutions to the palaeostress problem. Examples of different applications of the new stress inversion method are described, including the analysis of fault data from boreholes. These examples illustrate the way the new method potentially broadens the scope of palaeostress analysis.