Journal of Petrology | Volume 39 | Number 11-12 | Pages 2043-2059 | 1998
© Oxford University Press 1998
Magmatic Evolution of the Melilitite–Carbonatite–Nephelinite Dyke Series of the Turiy Peninsula (Kandalaksha Bay, White Sea, Russia)
1 Department of Petrology, Geological Faculty, St Petersburg University St Petersburg, 199031, RUSSIA
2 Ottawa–Carleton Geoscience Centre, Department of Earth Sciences, Carleton University Ottawa, Ont., CANADA, K1S 5B6
Received September 30, 1997; Revised typescript accepted June 16, 1998
| Abstract |
|---|
Major and trace element data are presented from a suite of melilitite–carbonatite–nephelinite dykes, the youngest of three dykes swarms in the Turiy peninsula, Russia. The most primitive dykes consist of olivine melanephelinites and olivine–melilite melanephelinites that contain high-pressure phases (Cr-diopside and low-Ca forsteritic olivine). These dykes approximate the composition of the parental melt, which probably originated by low-degree partial melting of metasomatized peridotite. Least-squares mass-balance calculations and geochemical modelling indicate that differentiation was controlled by fractional crystallization involving olivine, clinopyroxene, melilite, Ti-magnetite, apatite, and perovskite. The calculated modal proportions of the cumulate minerals correspond to some of the rocks seen in alkaline ultramafic plutons elsewhere in the Kola peninsula. Calciocarbonatite dykes, with quenched primary magmatic fabrics, were probably continuously separated by liquid immiscibility from an evolved carbonated nepheline melilitite parent. The conjugate silicate liquid to the carbonatitic melt is a melilite nephelinite. The distribution of LREE, Zr, Hf, Ta, W, Pb, and Cu between the carbonatite and melilite nephelinite is in reasonable agreement with experimental data on element partitioning between alkaline silicate and carbonate melts.
KEY WORDS: carbonatite; fractional crystallization; Turiy peninsula; liquid immiscibility
* Corresponding author.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
D. Wiedenmann, A. N. Zaitsev, S. N. Britvin, S. V. Krivovichev, and J. Keller Alumoakermanite, (Ca,Na)2(Al,Mg,Fe2+)(Si2O7), a new mineral from the active carbonatite-nephelinite-phonolite volcano Oldoinyo Lengai, northern Tanzania Mineralogical Magazine, June 1, 2009; 73(3): 373 - 384. [Abstract] [Full Text] [PDF] |
||||
