A PRE-D2 AGE FOR THE 590-MA BEN-VUIRICH GRANITE IN THE DALRADIAN OF SCOTLAND

Regional mapping demonstrates that S2 is the main fabric in the Centra l Highland Dalradian and that it is this fabric, not S3 as previously thought, which overprints the 590 Ma Ben Vuirich granite. The granite appears to have been emplaced following a tectonic event (D1) in the D alradian rocks, for a finely-spaced penetrative fabric seen in newly-d iscovered hornfelses from the granite aureole is overgrown by contact metamorphic cordierite and andalusite porphyroblasts (now both altered ) which predate the D2 metamorphism.