仰冲(Obduction)是一种地质过程,指密度更大的洋壳聚合性板块边缘处从下降的海洋板块上被剥离,并推覆到到邻近板块上[1]。这邻近的板块也可能是密度小的陆壳[2]。仰冲不如俯冲常见[3],因为密度较大的大洋岩石圈通常会在较轻的大陆板块下方俯冲。仰冲与造山带弧后盆地的板块碰撞有关[4]

仰冲通常发生在俯冲带,大洋壳中的基性和超基性岩石碎块从地幔逆冲到大陆地壳上,成为蛇绿岩套[5]。仰冲也会发生在一个小的洋壳板块夹在两个较大的大陆板块之间,当两个大陆板块碰撞时,夹在它们之间的洋壳被挤入到相邻的大陆板块之间,由此产生造山运动[6]。 大多数仰冲一般在俯冲带上方的弧后盆地开始,在洋壳闭合或造山运动期间完成[7]

仰冲的例子有新喀里多尼亚塞浦路斯特罗多斯山

参考文献

编辑
  1. ^ Plate Tectonics > Glossary > M - R. [2021-10-10]. (原始内容存档于2021-10-10). 
  2. ^ Plate tectonics Glossary M-R https://www.geolsoc.org.uk/Plate-Tectonics/Glossary/M-R页面存档备份,存于互联网档案馆
  3. ^ Sarah J. Edwards, Wouter P. Schellart, Joao C. Duarte. Geodynamic models of continental subduction and obduction of overriding plate forearc oceanic lithosphere on top of continental crust: 1494-1515. [2021-10-10]. (原始内容存档于2022-03-06). 
  4. ^ Curved orogenic belts, back-arc basins, and obduction as consequences of collision at irregular continental margins (PDF). 
  5. ^ Dewey, J. F., 1976. Ophiolite Obduction. Tectonophysics, v. 31, p.93-120
  6. ^ Dewey, J. F. and Bird, J.M., 1971. Origin and emplacement of the ophiolite suite: Appalachian ophiolites in Newfoundland. J. Geophys. Res., 76:3179-3206
  7. ^ Church, W. R., 1972. Ophiolite: its definition, origin as oceanic crust, and mode of emplacement in orogenic belts, with special reference to the Appalachians. Dep. Energy, Mines Resource. Can., Publ., 42:71-85