ON THE COMPOSITION AND ZONING OF ACCESSOR Y MINERALS OF ALKALINE-ULTRABASIC ROCKS AS AN INDICATOR OF THE COMPOSITION AND PECULARITIES OF PRIMARY MAGMATIC DIFFERENTIATION

Citation
It. Rass et Ip. Laputina, ON THE COMPOSITION AND ZONING OF ACCESSOR Y MINERALS OF ALKALINE-ULTRABASIC ROCKS AS AN INDICATOR OF THE COMPOSITION AND PECULARITIES OF PRIMARY MAGMATIC DIFFERENTIATION, Geohimia, (5), 1995, pp. 720-732
Citations number
44
Categorie Soggetti
Geosciences, Interdisciplinary
Journal title
ISSN journal
00167525
Issue
5
Year of publication
1995
Pages
720 - 732
Database
ISI
SICI code
0016-7525(1995):5<720:OTCAZO>2.0.ZU;2-C
Abstract
The composition and zoning of perovskite and apatite crystals of 30 sa mples of alkaline-ultrabasic rocks and carbonatites from massifs (Guli , Kugda) of Meimecha-Kotuy province (NW of Siberian platform) and Turi y of Karelian-Kola province (Kola peninsula) was studied. It was estab lished that main components of studied minerals are weakly variable wh ereas the content of FeO, Mb(2)O(5), SrO, La2O3 and CeO2 in perovskite s and SrO, La2O3, and CeO2 in apatites are found to be variable along 3 trends: from the center to the peripheric zones of crystals; in succ essive derivates of the alkaline-ultrabasic rocks; in different massif s. It was shown that the distribution of elements in the zonal crystal s is governed by the petrological type of alkaline-ultrabasic rocks. T he latter are differing in melilite content and are considered as repr esentatives of two different rocks series being derived from different initial magmas.