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在最近十年中,人们知道了韧性岩石中意义最大的剪切判据都是不对称构造(例如压力影、剪切带、C-S构造、组构、张裂隙、褶皱、岩脉)。共轴变形或非共轴变形与对称的质点速度场或不对称的质点速度场之间的对应关系,分别说明了构造的对称性可用作应变历史的标志。在各种野外实例中应用这种对称概念时要强调:(1)已知构造模式的对称程度反映了总体应变状态,与所研究系统的大小和力学特性无关;(2)总体应变状态也可由对总体变形模式产生影响的构造出现的次序和优选性来推断,甚至在递进变形导致产生不能直接判读的复杂模式的地方也是如此。
In the last decade, people have learned that the most significant shear criteria in ductile rocks are all asymmetric structures (eg, pressure shadow, shear band, C-S structure, structure, zonal fracture, fold, dyke). The correspondence between co-axial or non-co-axial deformations and symmetrical mass velocity fields or asymmetric particle velocity fields respectively indicates that the symmetry of the structure can be used as a marker of strain history. When applying this concept of symmetry to a variety of field examples, it is emphasized that: (1) The degree of symmetry of known tectonic patterns reflects the overall strain state independent of the size and mechanical properties of the studied system; (2) the overall strain state can also be defined by Inferences about the order and preference of constructs that affect the overall deformation pattern lead to inferences even where progressive deformation leads to complex patterns that can not be directly interpreted.