NJG87-4-04
2007
A new occurrence of aegirine in Norway
87
4
pp. 451-456
978-82-92-39441-0

The Hortavær Complex in north-central Norway is a well documented example of the formation of an alkaline magmatic suite due to the assimilation of carbonate and calc-silicate rocks (Vogt 1916; Gustavson & Prestvik, 1979; Barnes et al. 2003, 2005). In addition to calcic pyroxene, aegirine occurs in veins near skarn-like assemblages in a zone where dioritic sheets were emplaced into syenite. Other vein minerals are biotite, albite, K-feldspar, calcite, and ilmenite. The aegirine is almost pure NaFeSi2 O6 . Laser-ablation ICP-MS analysis shows that the aegirine crystals are typically lower in trace element concentrations than the calcic clinopyroxene of the complex. Chondrite-normalized rare earth element (REE) patterns show a prominent cup shape, and light REE abundances range from ~ 0.1x to > 10x chondrites.

Tore Prestvik: Department of Geology and Mineral resources Engineering, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
Calvin G. Barnes: Department of Geosciences, Texas Tech University, Lubbock, TX 79409-1053, USA

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