交错层理

交错层理(英语:cross bedding),也称为斜层理(英语:cross lamination),是在一层地层内由一系列斜交于层系界面的纹层组成的层理,细层理上部与主层理截交,下部与主层理相切[1]。主层理面是平行与当时的水平面,而倾斜的纹层理代表原始局部的沉积面。这种倾斜不是由于沉积后变形的结果,而是由颗粒沿水底面被水拖引到倾斜地面后沉积形成[2]

例如在河底波纹河边沙洲风成沙丘浅海三角洲前缘斜坡等沉积环境都能形成交错层理[3]。交错层理一般可分为板状交错层理及槽状交错层理两种。前者上下层理面是平面,后者层理面为弧形[4],此外还有楔状交错层理等共八种层理。根据交错层理的几何形状亦可推测沉积环境及流体方向[5]

参考文献

  1. ^ Jordan, Thomas H.; Grotzinger, John P. (2012). The Essential Earth (2nd ed.). New York: W.H. Freeman. ISBN 9781429255240. OCLC 798410008
  2. ^ John Collinson ,(2019) Sedimentary structures. Dunedin Academic Press Ltd, Mar 1, 2019 - Technology & Engineering - 320 pages. ISBN 1780466021, 9781780466026
  3. ^ Ashley, G. (1990) "Classification of Large-Scale Subaqueous Bedforms: A New Look At An Old Problem." Journal of Sedimentary Petrology. 60.1: 160-172
  4. ^ Boggs, S., 2006, Principles of Sedimentology and Stratigraphy (4th ed): Pearson Prentice Hall, Upper Saddle River, NJ
  5. ^ Ashley, G. (1990) "Classification of Large-Scale Subaqueous Bedforms: A New Look At An Old Problem." Journal of Sedimentary Petrology. 60.1: 160-172