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俯衝帶變質作用

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俯衝帶變質作用(英語:subduction zone metamorphisim)是指在岩石圈向下俯衝過程中,所經歷的低溫,高到超高壓變質環境,形成的一系列的變質岩相的礦物組合[1]。由淺到深,變質岩相是沸石相(英語:zeolite facoies)、葡萄石-绿纤石相藍片岩相和榴輝岩相(英語:eclogite facies[2][3] [4].俯衝板塊由玄武質地殼和上覆遠海沉積物組成, 然而,遠海沉積物多半被增生到弧前地區而不俯衝到深部[5]。在俯衝中,板塊的變質多半是由含水礦物脫水引起的。含水礦物的分解通常在 10 公里的深度開始,將水釋放到地幔中。從而降低了地幔岩石的熔點,引發了部分熔融[6]。 這些變質岩相中,每一個都有指標礦物組合,代表其經歷的變質環境[7]。 了解這些脫水反應發生的時間和條件,是解釋地幔熔融、火山弧岩漿作用和大陸地殼形成的關鍵[8]

參考文獻

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  1. ^ Tatsumi, Yoshiyuki (2005). "The subduction factory: How it operates in the evolving Earth" (PDF). GSA Today. 15 (7): 4. doi:10.1130/1052-5173(2005)015[4:TSFHIO]2.0.CO;2. Retrieved December 3, 2014.
  2. ^ Zheng, Y.-F., Chen, R.-X., 2017. Regional metamorphism at extreme conditions: Implications for orogeny at convergent plate margins. Journal of Asian Earth Sciences 145, 46-73
  3. ^ Winter, John D. (2010). Principles of Igneous and Metamorphic Petrology. Prentice Hall. pp. 541–548. ISBN 978-0-321-59257-6
  4. ^ Reynolds, Stephen (2012-01-09). Exploring Geology. McGraw-Hill. p. 124. ISBN 978-0073524122
  5. ^ Bebout, Grey E. (May 31, 2007). "Metamorphic Chemical Geodynamics of Subduction". Earth and Planetary Science Letters. 260: 375. Bibcode:2007E&PSL.260..373B. doi:10.1016/j.epsl.2007.05.050
  6. ^ Peacock, Simon M. (1 January 2004). "Thermal Structure and Metamorphic Evolution of Subducting Slabs". In Eiler, John (ed.). Inside the subduction factory. Geophysical Monograph Series. 138. American Geophysical Union. pp. 12–15. ISBN 9781118668573
  7. ^ "How Volcanoes work – Subduction Zone Volcanism". San Diego State University Department of Geological Science
  8. ^ Mibe, Kenji; et al. (2011). "Slab melting versus slab dehydration in subduction zones". Proceedings of the National Academy of Sciences. 108 (20): 8177–8182. doi:10.1073/pnas.1010968108. PMC 3100975. PMID 21536910