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岩蓋

維基百科,自由的百科全書
岩蓋入侵並使頂層的沉積岩變形
侵入岩結構的基本構成
1. 岩蓋
2. 小的岩脈
3. 岩磐
4. 岩脈
5. 岩干
6. 火山頸
7. 岩盆

岩蓋(英語:Laccolith)是一種片狀的侵入體(或是一致的深成岩體)。它侵入到了沉積岩層內或層之間;當母岩為火山岩時,該岩蓋被稱為隱形穹(cryptodomes)[1]。由於岩漿的壓力足夠高,以致上覆岩層被迫向上並隆起,從而使岩蓋在並具有基本平坦的底部的同時頂部呈圓拱或蘑菇狀(也可能為圓錐形或楔形)。 隨著時間的流逝,侵蝕可能會使岩蓋的頂部周圍形成小山甚至山巒,因為岩漿岩可能比作為基質的沉積岩更能抵抗風化。 當岩漿向上侵入時,岩蓋的生長可能在幾個月的時間里發生[2][3] 。而由於多個岩漿脈彼此疊加使基岩變形時,岩蓋的形成則可能需要數百或數千年的時間[4]

參考資料

  1. ^ Burchardt, Steffi; Mattsson, Tobias; Palma, J. Octavio; Galland, Olivier; Almqvist, Bjarne; Mair, Karen; Jerram, Dougal A.; Hammer, Øyvind; Sun, Yang. Progressive Growth of the Cerro Bayo Cryptodome, Chachahuén Volcano, Argentina—Implications for Viscous Magma Emplacement. Journal of Geophysical Research: Solid Earth. 2019-08-14, 124 (8): 7934–7961. Bibcode:2019JGRB..124.7934B. ISSN 2169-9313. doi:10.1029/2019JB017543. 
  2. ^ Castro, Jonathan M.; Cordonnier, Benoit; Schipper, C. Ian; Tuffen, Hugh; Baumann, Tobias S.; Feisel, Yves. Rapid laccolith intrusion driven by explosive volcanic eruption. Nature Communications. December 2016, 7 (1): 13585. Bibcode:2016NatCo...713585C. ISSN 2041-1723. PMC 5123016可免費查閱. PMID 27876800. doi:10.1038/ncomms13585. 
  3. ^ Mattsson, Tobias; Burchardt, Steffi; Almqvist, Bjarne S. G.; Ronchin, Erika. Syn-Emplacement Fracturing in the Sandfell Laccolith, Eastern Iceland—Implications for Rhyolite Intrusion Growth and Volcanic Hazards. Frontiers in Earth Science. 2018-02-05, 6: 5. Bibcode:2018FrEaS...6....5M. ISSN 2296-6463. doi:10.3389/feart.2018.00005. 
  4. ^ Morgan, Sven; Stanik, Amy; Horsman, Eric; Tikoff, Basil; de Saint Blanquat, Michel; Habert, Guillaume. Emplacement of multiple magma sheets and wall rock deformation: Trachyte Mesa intrusion, Henry Mountains, Utah. Journal of Structural Geology. April 2008, 30 (4): 491–512. Bibcode:2008JSG....30..491M. doi:10.1016/j.jsg.2008.01.005. 
  • Blatt, Harvey and Robert J. Tracy, 1996, Petrology: Igneous, Sedimentary and Metamorphic, 2nd ed., pp. 13–15, Freeman, ISBN 0-7167-2438-3
  • Jules D. Friedman and Curtis Huffman, Jr., coordinators, "Laccolith Complexes of Southeastern Utah: Time of Emplacement and Tectonic Setting -- Workshop Proceedings"頁面存檔備份,存於網際網路檔案館), United States Geological Survey Bulletin 2158, 1998.
  • Hyndman, D. W. and D. Alt "Radial Dikes, Laccoliths, and Gelatin Models." ' 'Journal of Geology. 95:763-774.

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