Physical models of transtensional folding
Physical models of transtensional folding
复制标题
拉伸折叠的物理模型
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
B. Tikoff
中科院分区：
文献类型：
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作者：
Maitri Venkat;B. Tikoff
张扭变形的物理模型表明，在板块发散角从0°到30°的范围内，褶皱的形成。褶皱是直立的，褶皱轴面垂直于所有倾斜发散角。扭张褶皱枢纽平行于最大水平无限小伸展方向启动，并随着最大水平有限伸展向平行于斜向运动方向（而不是剪切带边界）旋转。大量的铰链平行延伸发生在折叠形成和材料线观察到通过折叠铰链在渐进变形。张扭褶皱实验强化了假设地质构造与应变或应力之间简单一致的缺陷。在22°和30°斜向发散实验中，观测到的褶皱轴面既不垂直于最大收缩方向（S3），也不垂直于推测的最大压应力方向（σ 1）。因此，在根据张扭过程中形成的褶皱的方向来解释主应变方向，特别是主应力方向时，必须谨慎。
Physical models of transtensional deformation indicate the formation of folds for a range of plate divergence angles from 0° to 30°. Folds are upright and fold axial planes are vertical for all angles of oblique divergence. The transtensional fold hinges are initiated parallel to the direction of the maximum horizontal infinitesimal extension and rotate with the maximum horizontal finite extension toward parallelism with the oblique movement direction (not the shear-zone boundary). Large amounts of hinge-parallel extension occur during fold formation and material lines are observed to rotate through the fold hinges during progressive deformation. The transtensional folding experiments reinforce the pitfalls of assuming a simple coincidence between geological structures and strain or stress. For the 22° and 30° obliquely divergent experiments, the observed fold axial planes are not perpendicular to the maximum contraction direction (S 3 ) or the inferred maximum compressive stress direction (σ 1 ). Consequently, one must be cautious in making interpretations of principal strain directions, and especially principal stress directions, based on the orientations of folds formed in transtension.