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Vol. 3 (2000 year), No. 2

Vrevsky A.B., Drugova G.M., Kozlov N.E., Skublov S.G.
On geochemistry of rare earth elements in the Lapland Granulite Complex (the Baltic Shield)

The new data on the distribution of the rare earth elements (REE) in the Lapland Granulite Complex (LGC) for Yavr, Lotta and Lovozero allow to conclude that Lovozero norites and gabbronorites belong to a single magmatic series, REE contents of which is determined by their silicicity. These metaintrusive rocks are quite different from the basic schists (metavolcanics of the tholeiitic and calc-alcali formation) by higher content of light lanthanides and by more differentiated distribution of them. The intrusive enderbites reveal the analogous difference and they also possess of high positive europium anomaly. The similar REE distribution is presented in the garnetiferous granites from the paragneises unit. This fact underlies their similar geological position with the displaced enderbites. The content and REE distribution in the garnet gneisses of the Yavr and Lotta districts show their practical identity that along with the petrologic data determine their belonging to a single granulite complex. Low negative EU-anomaly in gneisses mates with the positive Eu-anomaly in granites and this may be a result of the Eu-redistribution in the period of migmatization and anatexis. The curves of REE distribution in the gneisses of the LGC are similar to ones of the Kola series of the Archaean age. This phenomenon and the relations of Th-Hf-Co and Th-La-Sc and the content level of some REE (Cr, Ni) make it possible to determine the protolith of the LGC as Archaean.

(in Russian, стр.10, fig. 10, tables. 3, ref 13, MS Word 95, MS Word 95 305 Kb)