交錯層理

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交錯層理(英語:cross bedding),也稱為斜层理(英語:cross lamination),是在一層地層內由一系列斜交于层系界面的纹层组成的層理,细层理上部与主层理截交,下部与主层理相切[1]。主層理面是平行與當時的水平面,而傾斜的紋层理代表原始局部的沉積面。這種傾斜不是由於沉積後變形的結果,而是由顆粒沿水底面被水拖引到傾斜地面后沉積形成[2]

例如在河底波紋河邊沙洲風成沙丘淺海三角洲前緣斜坡等沉積環境都能形成交錯層理[3]。交錯層理一般可分为板状交错层理及槽状交错层理兩種。前者上下層理面是平面,後者層理面为弧形[4],此外還有楔状交错层理等共八種层理。根據交錯層理的幾何形狀亦可推測沉積環境及流體方向[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