ANALELE ŞTIINŢIFICE ALE UNIVERSITĂŢII „AL. I. CUZA” IAŞI Geologie. Tomul LVI, nr. 2, 2010 GEOCHEMISTRY OF SELECTED GARNETS IN PEGMATITES FROM THE RĂZOARE FORMATION (PRELUCA MOUNTAINS, ROMANIA) SMARANDA SÎRBU 1 , NICOLAE BUZGAR 2 , HAINO UWE KASPER 3 1 “Al. I. Cuza” University of Iaşi, Faculty of Geography and Geology, Department of Research, 20A Carol I Blv., 700505 Iaşi, Romania 2 “Al. I. Cuza” University of Iaşi, Faculty of Geography and Geology, Department of Geology, 20A Carol I Blv., 700505 Iaşi, Romania 3 Universität zu Köln, Institut für Geologie und Mineralogie, 49a Zülpicher Str., 50674 Köln, Germany Abstract The Răzoare formation, part of the Preluca Mountains from NW Romania, is the host of granitic pegmatites rich in garnets. The large garnet grains of dark pink colour are associated with quartz, muscovite and albite. Generally, garnet is a common accessory mineral in granitic pegmatites associated with granite, and its composition denotes the nature of the crystallization environment. The investigated garnets display a significant spessartine content (about 30 mol %), which is typical for garnets from magmatic pegmatites. The REE pattern and the Y, Li, Nb/Ta, Zr/Hf and Sc contents support the magmatic origin of the pegmatites investigated. This sum of geochemical features points to the development of the rocks from a peraluminous melt rich in volatile components which are involved in the enhancement of trace element mobility during the differentiation processes. Keywords: garnet, pegmatites, trace elements, Răzoare formation, Preluca Mountains. Introduction Garnet is a typical accessory mineral in granite pegmatites. The solid-solution of garnet belongs to the almandine-spessartine series, while the spessartine content increases along with the geochemical evolution of pegmatites. Thus, in granite pegmatites of the rare elements class 1 e-mail: sradasanu@yahoo.com