Инд. авторы:	Marschall H.R., Korsakov A.V., Luvizotto G.L., Nasdala L., Ludwig T.
Заглавие:	On the occurrence and boron isotopic composition of tourmaline in (ultra)high-pressure metamorphic rocks
Библ. ссылка:	Marschall H.R., Korsakov A.V., Luvizotto G.L., Nasdala L., Ludwig T. On the occurrence and boron isotopic composition of tourmaline in (ultra)high-pressure metamorphic rocks // Journal of the Geological Society. - 2009. - Vol.166. - Iss. 4. - P.811-823. - ISSN 0016-7649.
Внешние системы:	DOI: 10.1144/0016-76492008-042; SCOPUS: 2-s2.0-69949125683;
Реферат:	eng: The extensive P-T stability and the high chemical variability of tourmaline (Tur) together with its common occurrence in metasediments proves its high potential for petrological and (isotope) geochemical studies on fluid-rock interaction in subduction- and collision-related rocks. This paper reviews the occurrence, major element chemistry and boron isotopic composition of Tur in high- and ultrahigh-pressure metamorphic (UHPM) rocks. In addition, it presents a new discovery of coesite-bearing Tur (schorl) from the Erzgebirge (Germany), as well as Tur (dravite) related to the retrograde history of coesite- and diamond-bearing rocks from the Erzgebirge and the Kokchetav Massif (Kazakhstan). The scarce data on worldwide occurrences of (U)HPM Tur reveal a high occupation of the crystallographic X-site (dominated by Na) and the possible presence of excess B, with little further distinctiveness in its major element composition when compared with Tur from medium-grade rocks. High K2O contents in Tur are probably not related to UHP growth or equilibration. The B isotopic composition of (U)HPM Tur ranges in 11B from 16 to +1‰, with many samples in or below the range of continental crust. In contrast, Tur formed during retrograde fluid influx typically shows high 11B values (up to +28‰), suggesting heavy-B fluids infiltrating the exhuming (U)HPM units. Coesite inclusions in Tur, characterized by Raman spectroscopy, are regarded as the best indicator for its UHP stability. © 2009 Geological Society of London.
Ключевые слова:	Kokchetav Massif; Kazakhstan; Europe; Eurasia; Erzgebirge Mountains; Central Europe; Asia; water-rock interaction; ultrahigh pressure metamorphism; West Asia; retrograde metamorphism; P-T conditions; metasediment; isotopic composition; geochemistry; fluid inclusion; diamond; coesite; boron; tourmaline;
Издано:	2009
Физ. характеристика:	с.811-823