过碱性岩石

过碱性岩石（英语：Peralkaline rock）是指缺乏铝的火成岩。它们的钠和钾的含量超过了形成长石所需的含量。通常岩石有霓石(aegerine)和铁钠闪石 (riebeckite)就代表过碱性的地质环境。例如过碱性流纹岩、钠闪碱流岩(comendite) 和碱流岩(pantellerite) ^[1]，其中 comendite 是含长石质更多（含二氧化矽多）的岩石^[2]。另一个例子是在北大西洋 Rockall 岛的高碱性花岗岩 ^[3]。

过碱性岩石代表与大陆裂谷相关的火山活动（例如肯尼亚中部东非裂谷的过碱性流纹岩）以及与大陆和海洋热点的火山活动（例如澳大利亚东部玻璃屋山和加那利群岛的过碱性流纹岩）^[4] ^[5]^[6]。火山活动在俯冲带亦有报导过碱性岩石的实例（例如意大利的撒丁岛）^[5]。

当分离结晶去除斜长石，比去除镁铁质矿物更多时，可能会形成过碱性岩浆^[7]。

参考文献

^ Philpotts, Anthony R.; Ague, Jay J. (2009). Principles of igneous and metamorphic petrology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 143–146. ISBN 9780521880060.
^ McBirney, Alexander R. (1984). Igneous petrology. San Francisco, Calif.: Freeman, Cooper. p. 502. ISBN 0198578105.
^ Sutherland, D. S. (editor) (1982). Igneous Rocks of the British Isles. Chichester: John Wiley and Sons. p. 413. ISBN 978-0-471-27810-8.
^ Scaillet, Bruno; Macdonald, Ray (2003). "Experimental Constraints on the Relationships between Peralkaline Rhyolites of the Kenya Rift Valley". Journal of Petrology. 44 (10): 1867–1894. Bibcode:2003JPet...44.1867S. doi:10.1093/petrology/egg062
^ ^5.0 ^5.1 Shao, Fengli; Niu, Yaoling; Regelous, Marcel; Zhu, Di-Cheng (2015). "Petrogenesis of peralkaline rhyolites in an intra-plate setting: Glass House Mountains, southeast Queensland, Australia". Lithos. Elsevier. 216: 196–210. Bibcode:2015Litho.216..196S. doi:10.1016/j.lithos.2014.12.015. ISSN 0024-4937.
^ Troll, Valentin R.; Schmincke, Hans-Ulrich (2002). "Magma Mixing and Crustal Recycling Recorded in Ternary Feldspar from Compositionally Zoned Peralkaline 'A', Gran Canaria, Canary Islands". Journal of Petrology. Oxford Academic Journals. 43 (2): 246. doi:10.1093/petrology/43.2.243. ISSN 0022-3530.
^ McBirney 1984, pp. 396–397.

[”1”-1] Philpotts, Anthony R.; Ague, Jay J. (2009). Principles of igneous and metamorphic petrology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 143–146. ISBN 9780521880060.

[”2”-2] McBirney, Alexander R. (1984). Igneous petrology. San Francisco, Calif.: Freeman, Cooper. p. 502. ISBN 0198578105.

[”3”-3] Sutherland, D. S. (editor) (1982). Igneous Rocks of the British Isles. Chichester: John Wiley and Sons. p. 413. ISBN 978-0-471-27810-8.

[”4”-4] Scaillet, Bruno; Macdonald, Ray (2003). "Experimental Constraints on the Relationships between Peralkaline Rhyolites of the Kenya Rift Valley". Journal of Petrology. 44 (10): 1867–1894. Bibcode:2003JPet...44.1867S. doi:10.1093/petrology/egg062

[”5”-5] 5.0 ^5.1 Shao, Fengli; Niu, Yaoling; Regelous, Marcel; Zhu, Di-Cheng (2015). "Petrogenesis of peralkaline rhyolites in an intra-plate setting: Glass House Mountains, southeast Queensland, Australia". Lithos. Elsevier. 216: 196–210. Bibcode:2015Litho.216..196S. doi:10.1016/j.lithos.2014.12.015. ISSN 0024-4937.

[”6”-6] Troll, Valentin R.; Schmincke, Hans-Ulrich (2002). "Magma Mixing and Crustal Recycling Recorded in Ternary Feldspar from Compositionally Zoned Peralkaline 'A', Gran Canaria, Canary Islands". Journal of Petrology. Oxford Academic Journals. 43 (2): 246. doi:10.1093/petrology/43.2.243. ISSN 0022-3530.

[”7”-7] McBirney 1984, pp. 396–397.

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