Инд. авторы:	Kamenetsky V.S., Charlier B., Zhitova L, Sharygin V.V., Davidson P., Feig S.
Заглавие:	Magma chamber-scale liquid immiscibility in the siberian traps represented by melt pools in native iron
Библ. ссылка:	Kamenetsky V.S., Charlier B., Zhitova L, Sharygin V.V., Davidson P., Feig S. Magma chamber-scale liquid immiscibility in the siberian traps represented by melt pools in native iron // Geology. - 2013. - Vol.41. - Iss. 10. - P.1091-1094. - ISSN 0091-7613. - EISSN 1943-2682.
Внешние системы:	DOI: 10.1130/G34638.1; SCOPUS: 2-s2.0-84884526685; WoS: 000327391200013;
Реферат:	eng: Magma unmixing (i.e., separation of a homogeneous silicate melt into two or more liquids) is responsible for sudden changes in the evolution of common melts, element fractionation, and potential formation of orthomagmatic ore deposits. Although immiscible phases are a common phenomenon in the mesostasis of many tholeiitic basalts, evidence of unmixing in intrusive rocks is more difficult to record because of the transient nature of immiscibility during decompression, cooling, and crystallization. In this paper, we document a clear case of liquid immiscibility in an intrusive body of tholeiitic gabbro in the Siberian large igneous province, using textures and compositions of millimeter-sized silicate melt pools in native iron. The native iron crystallized from a metallic iron liquid, which originated as disseminated globules during reduction of the basaltic magma upon interaction with coal-bearing sedimentary rocks in the Siberian craton. The silicate melts entrapped and armored by the native iron are composed of two types of globules that represent the aluminosilicate (60-77 wt% SiO2) and silica-poor, Fe-Ti-Ca-P-rich (in wt%: SiO2, 15-46; FeO, 15-22; TiO2, 2-7; CaO, 11-27; P2O5, 5-30) conjugate liquids. Different proportions and the correlated compositions of these globules in individual melt pools suggest a continuously evolving environment of magmatic immiscibility during magma cooling. These natural immiscible melts correspond extremely well to the conjugate liquids experimentally produced in common basaltic compositions at <1025 °C. Our results show that immiscibility can occur at large scale in magma chambers and can be instrumental in generating felsic magmas and Fe-Ti-Ca-P-rich melts in the continental igneous provinces. © 2013 Geological Society of America.
Ключевые слова:	Element fractionation; Igneous province; Siberian Craton; Russian Federation; tholeiitic basalt; silicate melt; sedimentary rock; ore deposit; melt; magma chamber; large igneous province; iron; immiscibility; gabbro; Different proportions; Silicates; Silica; Ore deposits; Lakes; Iron; Fractionation; Coal deposits; Calcium; Tholeiitic basalts; Liquid immiscibility; Large igneous provinces; Intrusive rocks; Immiscible phasis; Liquids;
Издано:	2013
Физ. характеристика:	с.1091-1094