气候变化领域集成服务门户(CCPortal): Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton; the largest durbachitic body in the Bohemian Massif

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DOI	10.1007/s00531-020-01872-2
	Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton; the largest durbachitic body in the Bohemian Massif
	Janoušek V.; Hanžl P.; Svojtka M.; Hora J.M.; Kochergina Y.V.E.; Gadas P.; Holub F.V.; Gerdes A.; Verner K.; Hrdličková K.; Daly J.S.; Buriánek D.
发表日期	2020
ISSN	14373254
起始页码	1767
结束页码	1810
卷号	109 期号:5
英文摘要	The Třebíč Pluton (TP) comprises plutonic rocks of the ‘durbachite series’, i.e., ultrapotassic biotite–amphibole quartz melasyenites–melagranites with conspicuous K-feldspar phenocrysts and abundant mafic enclaves. The TP with its satellite bodies intruded the eastern Moldanubian Zone (orogenic root of the Variscan Bohemian Massif) at c. 338 Ma. Overall, the entire TP durbachite series (SiO2 = 52–67 wt%) remains highly magnesian, reduced, and (except when strongly contaminated) metaluminous. The durbachitic rocks are markedly enriched in lithophile elements (esp. Cs, Rb, Th, U, K and Pb) and LREE; in contrast, the contents of high-field strength elements (Nb, Ta, and Ti) and Sr are much lower, resulting in conspicuous negative anomalies in Primitive mantle-normalized multielement plots. The proposed petrogenetic model requires re-enrichment of the depleted, harzburgitic lithospheric mantle by deeply subducted crustal material of the Saxothuringian lower plate, directly and/or via (U)HP melt/fluid. This process produced phlogopite-rich metasomes (phlogopite harzburgites and/or glimmerites). The metasomes re-melted soon thereafter by a short thermal pulse caused by slab break-off or decompression melting of rising diapirs of the relatively light metasomatized mantle, yielding primary ultrapotassic melts (87Sr/86Sr337 > 0.712 and εNd337 ≤ 7.6). Upon their passage through the Moldanubian upper plate, ultrapotassic primary magmas mixed with felsic anatectic melts (87Sr/86Sr337 < 0.710; εNd337 > – 6.5). K-feldspar-driven fractional crystallization ± accumulation represented only a late modifying influence. The occurrence of such ultrapotassic enriched/crustally contaminated mantle-derived magmatism complicates any conventional mass-balance assessments of relative roles of crustal recycling vs. growth in hot collisional orogens, e.g., Variscides or Himalayas. © 2020, Geologische Vereinigung e.V. (GV).
英文关键词	Bohemian Massif; Durbachites; Geochemistry; Třebíč Pluton; Ultrapotassic magmatism; U–Pb LA-ICP-MS zircon dating; Variscan Orogeny
语种	英语
scopus关键词	harzburgite; Hercynian orogeny; lithospheric structure; magma; magmatism; mantle structure; petrogenesis; pluton; plutonic rock; Bohemian Massif
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147652
作者单位	Czech Geological Survey, Klárov 3, Prague 1, 118 21, Czech Republic; Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, Prague 6, 165 00, Czech Republic; Institute of Petrology and Structural Geology, Charles University in Prague, Albertov 6, Prague 2, 128 43, Czech Republic; Institut für Geowissenschaften, Altenhöferallee 1, Frankfurt am Main, 60438, Germany; UCD School of Earth Sciences, Irish Centre for Research in Applied Geosciences (icrag-centre.org), University College Dublin, Belfield, Dublin 4, Ireland
推荐引用方式 GB/T 7714	Janoušek V.,Hanžl P.,Svojtka M.,et al. Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton; the largest durbachitic body in the Bohemian Massif[J],2020,109(5).
APA	Janoušek V..,Hanžl P..,Svojtka M..,Hora J.M..,Kochergina Y.V.E..,...&Buriánek D..(2020).Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton; the largest durbachitic body in the Bohemian Massif.International Journal of Earth Sciences,109(5).
MLA	Janoušek V.,et al."Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton; the largest durbachitic body in the Bohemian Massif".International Journal of Earth Sciences 109.5(2020).