弧前

弧前（英語：）是指海沟和火山弧之间的区域。包括增生楔和弧前盆地。弧前区位于会聚边缘。在俯冲过程中，下降大洋板块中的水和其他挥发物导致上地幔部分熔融，产生岩浆上升并穿透上覆板块，形成火山弧。 下行板块的重量使下行板块弯曲，形成海沟[1]。

从海沟到火山弧，岩石的变质程度會增加。在火山弧前区，变质程度最高可達到藍片岩和榴辉岩变质程度。這些弧前岩石被仰冲到大陸板块，就形成蛇绿岩套[2][3]。

随着板块汇聚，當一塊海洋板块完全消失在俯冲带時，就導致大陸和大陸或島弧和大陸碰撞，造成造山运动[4]。

參考文獻
  1. Klepeis, A. Keith; Fredrick, Vine J. (2009). Global Tectonics (3rd ed.). Singapore by Moarkono: J. Wiley. pp. 1–400. ISBN 978-1-4051-0777-8
  2. Fuller, C. W; Willet, S.D.; Brandon, M.T. (2006). "Formation of forearc basins and their influence on subduction zone earthquakes. Geological Society of America". Geological Survey of America. 34 (2): 65–68. doi:10.1130/g21828.1
  3. Kearey, Philip; Klepeis, A. Keith; Fredrick, Vine J. (2009). Global Tectonics (3rd ed.). Singapore by Moarkono: J. Wiley. pp. 1–400. ISBN 978-1-4051-0777-8
  4. Brown, D.; Spadea, P (2013). "Processes of forearc and accretionary complex formation during arc-continent collision in the southern Ural Mountains". Geology. 27 (7): 649–652. doi:10.1130/0091-7613(1999)027<0649:pofaac>2.3.co;2.
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