地学前缘 ›› 2007, Vol. 14 ›› Issue (6): 49-60.

• 论文 • 上一篇    下一篇

最大有效力矩准则及相关地质构造

郑亚东; 王涛; 王新社;

  

  1. 北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室

  • 出版日期:2008-06-30 发布日期:2008-06-30
  • 基金资助:

    国家自然科学基金资助项目(4027084,40472101,40572123)

The Maximum Effective Moment Criterion (MEMC) and related geological structures

  • Online:2008-06-30 Published:2008-06-30

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摘要：

摩尔-库伦准则广泛用以说明断裂构造的形成,然而却不能解释自然界广泛分布的大变形。最近提出的岩石变形新理论——最大有效力矩准则,其数学表达式为Meff=0.5(σ1-σ3)L.sin2α.sinα。式中,σ1-σ3代表变形岩石的屈服强度,L为单位长度,α为σ1与变形带间的角度。该准则证明最大有效力矩出现在σ1轴左右54.7°方向,55°±10°区间力矩无显著变化,天然和实验的全部观测值全部位于该区间内。相关地质构造包括:膝褶带、伸展褶劈理、膏盐层中的屈服带、低角正断层、高角逆断层、结晶基底中的菱网状剪切带、地震反射剖面中的鳄鱼嘴构造和前陆盆地中的拆离褶皱等。据该准则可确定有关构造形成时的应力状态和运动学涡度,并扩展说明深俯冲超高压岩石的折返-出露机制。

关键词:

最大有效力矩准则, 褶劈理, 低角正断层, 高角逆断层, 鳄鱼嘴构造, 菱形构造, 拆离褶皱,

Abstract:

The Mohr-Coulomb criterion has been widely used to explain the formation of fractures. However, it fails to explain large strain deformation that widely occurs in nature. There is presently a new theory, the MEMC, which is mathematically expressed as Meff=0.5 (σ1-σ3) L·sin 2α·sin α, where σ1-σ3 represents the yield strength of the related rock, L is a unit length and α is the angle between σ1 and deformation bands. This criterion demonstrates that the maximum value appears at angles of ±54.7° to σ1 and ther...

Key words:

maximum effective moment criterion, crenulation cleavage, low-angle normal fault, high-angle reverse fault, crocodile structure, lozenge structure, detachment fold,