FIRST EVIDENCE FOR LOWER CRETACEOUS HP HT-METAMORPHISM IN THE EASTERNRHODOPE, NORTH AEGEAN REGION, NORTHEAST GREECE/

In the Upper Unit of the Eastern Rhodope, North Aegean region, a Sm-Nd whole-rock, garnet and clinopyroxene isochron of a garnet-pyroxenite (metagabbro), corresponding to an age of 119.0 +/- 3.5 Ma, gives first evidence of a Lower Cretaceous UP-event in this area. The garnet-pyro xenites are characterised by the assemblage hornblende-spinel +/- oliv ine-garnet-clinopyroxene and are part of a metaperidotite complex This complex experienced HP/HT-metamorphism, together with the hosting met apelites and orthogneisses. In all rock types, this was followed by ne ar isothermal decompression during exhumation of the metamorphic rocks . In contrast to the situation in the host rocks, HP-mineral assemblag es of the investigated sample were not affected by plastic deformation and retrogression during decompression. It is thus assumed that the i sotopic equilibrium attained during HP/HT-metamorphism was not disturb ed during later events. In addition, Rb-Sr mica ages indicate differen tial uplift and different minimum ages of Alpine HP-metamorphism in qu artzofeldspathic rocks in different tectonic units of the Eastern Rhod ope.