Инд. авторы:	Panina L.I., Motorina I.V.
Заглавие:	Meimechites, porphyritic alkaline picrites, and melanephelinites of Siberia: Conditions of crystallization, parental magmas, and sources
Библ. ссылка:	Panina L.I., Motorina I.V. Meimechites, porphyritic alkaline picrites, and melanephelinites of Siberia: Conditions of crystallization, parental magmas, and sources // Geochemistry International. - 2013. - Vol.51. - Iss. 2. - P.109-128. - ISSN 0016-7029. - EISSN 1531-8397.
Внешние системы:	DOI: 10.1134/S0016702913020080; SCOPUS: 2-s2.0-84873508421; WoS: 000314333300002;
Реферат:	eng: The investigation of rocks, minerals, and melt inclusions showed that porphyritic alkaline picrites and meimechites crystallized from different parental magmas. At a similar ultrabasic composition, the alkaline picrite melts were enriched in K2O relative to Na2O, and contained up to 0. 12-0. 13 wt % F and less Cr, Ni, and H2O (only 0. 01-0. 16 wt % H2O, versus 0. 6-1. 6 wt % in the meimechite melts) compared with the meimechite magmas. The crystallization of alkaline picrite melts occurred under stable conditions at relatively low temperatures without abrupt changes: olivine and clinopyroxene crystallized at 1340-1285 and 1230-1200°C, respectively, as compared with 1600-1450 and 1230-1200°C in the meimechites. The alkaline picrite melts evolved toward melanephelinite, nephelinite, tephrite, and trachydolerite; whereas the meimechite magmas gave rise to subalkaline picritic rocks. The partitioning of vanadium between olivine and melt suggests that the meimechite magma crystallized under more oxidizing conditions compared with the alkaline picrite melts: the KDV values for the meimechite melts (0. 011-0. 016) were three times lower than those for the alkaline picrite melts (0. 045-0. 052). The parental magmas of the alkaline picrites and meimechites were enriched in trace elements relative to mantle levels by factors of tens to hundreds. The alkaline picrite magma showed lower LILE and LREE contents compared with the meimechite magma. The magmas had also different indicator ratios of incompatible elements, including those immobile in aqueous fluids. It was concluded that the meimechite and alkaline picrite melts were derived from different mantle sources. The former were generated at lower degrees of melting of an undepleted mantle source, and the meimechite melts were produced by high-degree melting of a probably lherzolite-harzburgite source. © 2013 Pleiades Publishing, Ltd.
Ключевые слова:	vanadium; trace element; porphyry; picrite; partitioning; olivine; nephelinite; melting; melt inclusion; mantle source; magma; lherzolite; harzburgite; crystallization; clinopyroxene; alkaline rock; Igneous rocks; Siberia; Sodium; Olivine; Melting; porphyritic alkaline picrite; parental magma; melanephelinite; Meimechite; Mantle source; Crystallization temperature; porphyritic alkaline picrite; parental magma; melanephelinite; meimechite; mantle source; degree of melting; crystallization temperature; Vanadium;
Издано:	2013
Физ. характеристика:	с.109-128