This paper reports the results of the first study of pyroxenes from the deepest zones of the Lovozero deposit. The geochemical and mineralogical study of these rocks is of great scientific interest, as they are the least differentiated rocks and provide insight into the composition of a parental magma. According to microprobe analysis, clinopyroxenes evolve from early diopside–hedenbergite–augite to later alkaline aegirine–augite species. Upsection, the contents of Na, Fe3+ and Ti increase, while Mg, Ca, Fe2+, and Zr decrease. Thus, isomorphic substitution in pyroxenes of the lower zone follows the scheme (Ca, Mg, Fe2+, Zr) → (Na, Fe3+, Ti).
Новые данные по геохимии корунда метасоматизированных ксенолитов «Рыжая незнакомка» и «Кукисвумчорр», Хибинский щелочной массив (Кольский полуостров)Филина М.И. 1 , Сорокина Е
New geochemical, mineralogical, and Rb–Sr and Sm–Nd isotopic data have been obtained on corundum plagioclasites–kyshtymites from the 5th Versta deposit (South Urals, Russia). The genetic link of miaskites and kyshtymites is shown. The formation of the kyshtymites is associated with the redistribution and accumulation of aluminum, calcium, HFSE, and LIL-elements at the stage of tectonic-metamorphic deformations of the Ilmenogorsky–Vishnevogorsky alkaline complex.
ВЫСОКОТИТАНИСТЫЙ КАЛИЕВЫЙ АМФИБОЛ ИЗ АГПАИТОВЫХ СИЕНИТОВ ИНТРУЗИИ НИВА И ДАЙКИ УЧАСТКА «МОХНАТЫЕ РОГА» (КОЛЬСКИЙ
The paper presents pioneering data on the composition of pyroxenes and the distribution of trace elements in this mineral in small geological bodies that were formed by single magma injections and their subsequent rapid crystallization: the Niva intrusion and an agpaitic syenite dyke. The pyroxene is highly alkaline and shows continuous compositional trends with an increase in the aegirine concentration. The Ti concentrations of the pyroxene are much higher than in pyroxenes in agpaitic syenites in other alkaline complexes. In spite of the fact that the pyroxene is hosted in small bodies, the evolution of these pyroxenes was similar to that of pyroxenes in the Lovozero and Khibina alkaline massifs.
