气候变化领域集成服务门户(CCPortal): Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif

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DOI	10.1130/B35019.1
	Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif
	Tomek F.; Žák J.; Svojtka M.; Finger F.; Waitzinger M.
发表日期	2019
ISSN	167606
起始页码	997
结束页码	1016
卷号	131 期号:2021-05-06
英文摘要	The late Carboniferous Altenberg-Teplice caldera in the northwestern Bohemian Massif provides an intriguing example of rhyolite eruptions evolving to a trapdoor collapse and coeval ring dike emplacement. Geochemical data suggest that withdrawal of an underlying stratified magma chamber beneath the caldera took place in two steps. Eruptions of the reversely zoned Teplice rhyolite drained the chamber, followed by a trapdoor collapse of the caldera floor and emplacement of voluminous microgranite ring dike system at 312 Ma. The mechanism proposed here is that the subsiding caldera floor increased vertical load on the magma chamber and triggered remobilization of residual, cumulate-like, and otherwise non-eruptible magma mush. The magnetic fabrics (determined using the anisotropy of magnetic susceptibility [AMS]), carried by paramagnetic ferrosilicates and titanomagnetite, indicate that the ring dike magma first flowed upwards via four main feeder domains from which the magma was then distributed laterally. The asymmetric trapdoor collapse generated domains of dilation and contraction along the caldera limit, evidenced by different shapes of fabric ellipsoids and uneven apparent width of the individual ring dike segments. Based on this case example, we develop a general kinematic model for polyphase caldera collapse and ring dike emplacement, invoking a combination of multiple space-making processes: piston and trapdoor collapses together with downsag and faulting of the caldera floor, regional tectonic extension, reactivation of the preexisting structures, and volume changes in the caldera floor due to thermal stresses. © 2018 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184914
作者单位	The Czech Academy of Sciences, Institute of Geology, Rozvojová 269, Prague, 16500, Czech Republic; Institute of Geology and Paleontology, Faculty of Science, Charles University, Albertov 6, Prague, 12843, Czech Republic; Department of Chemistry and Physics of Materials, University of Salzburg, Jakob Haringer Strasse 2A, Salzburg, A-5020, Austria
推荐引用方式 GB/T 7714	Tomek F.,Žák J.,Svojtka M.,et al. Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif[J],2019,131(2021-05-06).
APA	Tomek F.,Žák J.,Svojtka M.,Finger F.,&Waitzinger M..(2019).Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif.Bulletin of the Geological Society of America,131(2021-05-06).
MLA	Tomek F.,et al."Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif".Bulletin of the Geological Society of America 131.2021-05-06(2019).