Инд. авторы:	Mikhno A.O., Korsakov A.V.
Заглавие:	K2O prograde zoning pattern in clinopyroxene from the Kokchetav diamond-grade metamorphic rocks: Missing part of metamorphic history and location of second critical end point for calc-silicate system
Библ. ссылка:	Mikhno A.O., Korsakov A.V. K2O prograde zoning pattern in clinopyroxene from the Kokchetav diamond-grade metamorphic rocks: Missing part of metamorphic history and location of second critical end point for calc-silicate system // Gondwana Research. - 2013. - Vol.23. - Iss. 3. - P.920-930. - ISSN 1342-937X. - EISSN 1878-0571.
Внешние системы:	DOI: 10.1016/j.gr.2012.07.020; SCOPUS: 2-s2.0-84873138853; WoS: 000315543400006;
Реферат:	eng: Despite extensive studies of calc-silicate rocks of the Kokchetav massif, there is no satisfactory explanation of the origin of potassium-bearing clinopyroxene in alkali poor metamorphic rocks. In this paper we report the finding of potassium-bearing clinopyroxene with prograde zonation (K2O increases from core to rim) from diamond-grade, but diamond-free UHP calc-silicate rocks of the Kokchetav massif. We believe that the crystallization of potassium-bearing clinopyroxene started on the prograde stage and slightly prior to the peak of UHP metamorphism. Thus, prograde metamorphic history is only traceable in diamond-free UHP calc-silicate rocks, while in diamond-bearing UHPM rocks it is completely reset. Fluid and polyphase solid inclusions, originally representing melt inclusions, occur in the core of potassium-bearing clinopyroxene and imply that melt and fluid may coexist in calc-silicate rocks even at 1000-1100°C and 6-7GPa. © 2012 International Association for Gondwana Research.
Ключевые слова:	UHPM history; Second critical end point; Potassium-bearing clinopyroxene; Kokchetav massif; Fluid and partial melting;
Издано:	2013
Физ. характеристика:	с.920-930