SUBALKALINE GRANITES OF THE LAPLAND GRANU LITE NAPPES AS A GEOCHEMICAL ANALOG OF THE RAPAKIVI GRANITES

Geological and geochemical study of the microcline subalkaline granite s of the base of the Lapland granulite nappes was carried out. The gra nites are generaiy weakly foliated and form the sill-like bodies withi n garnet amfibolites, the latter being markers of the granulite nappes . Subalkaline granites are characterised with high content of K, Rb, G a, Zr, Y, REE and high values of K/Na and Fe/Mg ratios being close to the corresponding geochemical parameters of the rapakive granites of t he Southern Fennoscandia. Thus the studied rocks could be attributed t o A-type granites, so the former could be derived as a product of part ial melting of the lower crust stimulated by the abyssal fluids in the process of deep thrusting.