Micas of the phlogopite-annite series in rocks of the Khibiny massif (Kola Peninsula, Russia)

Konopleva N.G., Ivanyuk G. Yu., Pakhomovsky Ya. A., Yakovenchuk V. N., Mikhailova Yu. A.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 3. P. 87-103

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Language: Russian

Abstract

The paper displays data on the zoning of the Khibiny massif as related to content, morphology and composition of the biotite series minerals. Annite and phlogopite are accessory or rock-forming minerals in foyaites of the internal part of the massif and associated rischorrites, apatite-nepheline rocks, upstream melteigite-urtites, melanephelinites, carbonatized mica rocks and xenoliths of fenitized volcanic-sedimentary rocks of the Lovozerskaya suite. Chemical composition of biotite changes symmetrically to the massif center which is characterized by local maxima in concentration of Al, Mg and Mn, and minima of Si and Fe. In ore-bearing sectors of the Main Ring biotite is relatively enriched in Ca, Ba and Mg, and in barren sectors — in Na, Ca and Fe. While formation of more- and-more lower-temperature parageneses, the content of Si in biotite increases, and the Al content decreases.

Key words: annite, phlogopite, biotite, Khibiny massif, nepheline syenite, foidolite, typomorphism.