The petrology and chemistry of eleven leptynites from the Edough metamorphic complex are described. Geochemical studies suggest that the rocks are metamorphosed crustally-contaminated granites while detailed trace element modelling indicates they are neither partial melts of the intimately associated biotite orthogneisses nor they represent their more differentiated end-member. It is conducted that the leptynites are acid dykés or sills crystallised from a later magma relative to that from which the biotite orthogneisses were generated and hence cannot be used as a guide to the origin of the biotite gneisses.

Key words : Edough, leptynites, petrogenesis, S-type, dyke, sill.