气候变化领域集成服务门户(CCPortal): Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome; Bohemian Massif): petrogenesis and tectonic significance

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DOI	10.1007/s00531-020-01845-5
	Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome; Bohemian Massif): petrogenesis and tectonic significance
	Ilnicki S.; Szczepański J.; Pin C.
发表日期	2020
ISSN	14373254
起始页码	1247
结束页码	1271
卷号	109 期号:4
英文摘要	The Nové Město Unit and the northern part of the Zábřeh Unit comprise back-arc basin mafic rocks metamorphosed during Variscan times. In both units, nearly identical metabasites comprise variously enriched tholeiites (from N-MORB to transitional E-MORB-OIB), high-Ca, low-silica boninites and low-Ti tholeiites. The tholeiites (Ti/V: 22–58, εNd540: + 7.6 to − 4.7) represent 10–15% melting at ca. 30–60 km and temperatures of 1380–1230 °C of a depleted MORB mantle-type (DMM) wedge heterogeneously modified shortly before fusion by OIB-like melts (enriched mantle possibly of EM1–EM2 type) presumably derived from decompression melting of upwelling asthenosphere. Much less common meta-boninites (Ti/V: 6–23, εNd540: + 6.7 to − 2.9) formed by 15–25% re-melting of residual mantle (DMM after ~ 15% melt extraction) at depths of 40–65 km and temperatures of ~ 1420–1300 °C. Scarce low-Ti meta-tholeiites (Ti/V: 18–19, εNd540: + 7.1) resulted from < 10% melting of an unenriched DMM-type source or re-melting of residual mantle (after < 15% of former melting). Trace elements and Nd isotope compositions imply random fluxing of tholeiitic- and boninitic magma sources by components released from a subducted slab. The metasomatic enrichment (Th, LREE–MREE) was induced not only by sediment-derived melts but also by fluids supplied by subducted sediments or juvenile crust. The Nové Město–Zábřeh association of metabasites points to an easterly prolongation (in present-day coordinates) of the Cadomian subduction system of the Teplá–Barrandian. Boninite-type magmatism and OIB-like input into mantle beneath an extensional back-arc basin suggest an upflow of hot asthenosphere through subducted ridge (slab window) followed by a cessation of subduction zone activity. © 2020, The Author(s).
英文关键词	Back-arc basin; Boninites; Nd isotopes; Orlica–Śnieżnik dome; Tholeiites; Trace elements
语种	英语
scopus关键词	boninite; isotopic composition; mafic rock; mantle source; metabasite; petrogenesis; subduction zone; tectonic evolution; tectonic setting; tholeiite; trace element; 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/147674
作者单位	Institute of Geochemistry, Mineralogy and Petrology, Faculty of Geology, University of Warsaw, Al. Żwirki i Wigury 93, Warsaw, 02-089, Poland; Institute of Geological Sciences, Faculty of Earth Science and Environmental Management, University of Wroclaw, Pl. Maksa Borna 9, Wrocław, 50-205, Poland; Département de Géologie, C.N.R.S. Campus des Cézeaux, 6 Avenue Blaise Pascal, TSA 60026-CS 60026, Aubière Cedex, 63 178, France
推荐引用方式 GB/T 7714	Ilnicki S.,Szczepański J.,Pin C.. Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome; Bohemian Massif): petrogenesis and tectonic significance[J],2020,109(4).
APA	Ilnicki S.,Szczepański J.,&Pin C..(2020).Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome; Bohemian Massif): petrogenesis and tectonic significance.International Journal of Earth Sciences,109(4).
MLA	Ilnicki S.,et al."Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome; Bohemian Massif): petrogenesis and tectonic significance".International Journal of Earth Sciences 109.4(2020).