大陸碰撞

大陸碰撞（英語：continental collision）是一種在會聚邊界的板塊構造運動。這個運動開始於兩塊陸殼中間隔着一塊洋殼，一塊陸殼邊緣具有俯衝帶，而中間的洋殼就在俯衝帶下沉消失。在陸殼邊緣形成火山弧，如同現今的南美洲安第斯山脈^[1]^[2]。大洋地殼薄（約 6 公里厚）且緻密（約 3.3 g/cm³），由玄武岩、輝長岩和橄欖岩組成。因此，大多數洋殼在海溝處很容易俯衝。相比之下，大陸地殼較厚（約 45 公里厚）且有浮力，主要由花崗岩組成（平均密度約為 2.5 克/立方厘米）^[3]。

當另一陸地殼隨着下沉板塊到達海溝時，因陸地密度低抵抗俯衝，就和對方地殼碰撞。俯衝慢慢停止，火山弧也停止活動。在原海溝的地方造成海岸山脈。原海溝的位置成為也標誌着兩個地殼之間縫合帶。在縫合帶常有蛇綠岩套，代表原先海洋地殼和地幔岩石的碎片^[2]

參看文獻

^ Toussaint, G.; Burov, E.; Avouac, J.-P. (2004). "Tectonic evolution of a continental collision zone: A thermomechanical numerical model" (PDF). Tectonics. 23 (6): TC6003. Bibcode:2004Tecto..23.6003T. doi:10.1029/2003TC001604
^ ^2.0 ^2.1 O'Brien, P.J. (2001). "Subduction followed by collision; Alpine and Himalayan examples". Physics of the Earth and Planetary Interiors. 127 (1–4): 277–291. Bibcode:2001PEPI..127..277O. doi:10.1016/S0031-9201(01)00232-1
^ Ernst, W.G.; Maruyama, S. Wallis; Wallis, S. (1997). "Buoyancy-driven, rapid exhumation of ultrahigh-pressure metamorphosed continental crust". Proceedings of the National Academy of Sciences. 94 (18): 9532–9537. Bibcode:1997PNAS...94.9532E. doi:10.1073/pnas.94.18.9532. PMC 23212. PMID 11038569

[”Toussaint”-1] Toussaint, G.; Burov, E.; Avouac, J.-P. (2004). "Tectonic evolution of a continental collision zone: A thermomechanical numerical model" (PDF). Tectonics. 23 (6): TC6003. Bibcode:2004Tecto..23.6003T. doi:10.1029/2003TC001604

[”O'Brien”-2] 2.0 ^2.1 O'Brien, P.J. (2001). "Subduction followed by collision; Alpine and Himalayan examples". Physics of the Earth and Planetary Interiors. 127 (1–4): 277–291. Bibcode:2001PEPI..127..277O. doi:10.1016/S0031-9201(01)00232-1

[”-3] Ernst, W.G.; Maruyama, S. Wallis; Wallis, S. (1997). "Buoyancy-driven, rapid exhumation of ultrahigh-pressure metamorphosed continental crust". Proceedings of the National Academy of Sciences. 94 (18): 9532–9537. Bibcode:1997PNAS...94.9532E. doi:10.1073/pnas.94.18.9532. PMC 23212. PMID 11038569

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