First evidence for Lower Cretaceous HP/HT-Metamorphism in the Eastern Rhodope, North Aegean Region, North-East Greece
Wawrzenitz, Nicole; Mposkos, Evripidis
European Journal of Mineralogy Volume 9 Number 3 (1997), p. 659 - 664
published: Jun 2, 1997
manuscript accepted: Mar 11, 1997
manuscript received: Oct 31, 1996
ArtNo. ESP147050903012, Price: 29.00 €
Abstract 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 l 19.0 ± 3.5 Ma, gives first evidence of a Lower Cretaceous HP-event in this area. The garnet-pyroxenites are characterised by the assemblage hornblende-spinel ± olivine-garnet-clinopyroxene and are part of a metaperidotite complex. This complex experienced HP/HT-metamorphism, together with the hosting metapelites and orthogneisses. In all rock types, this was followed by near isothermal decompression during exhumation of the metamorphic rocks. In contrast to the situation in the host rocks, HP-mineral assemblages of the investigated sample were not affected by plastic deformation and retrogression during decompression. It is thus assumed that the isotopic equilibrium attained during HP/HT-metamorphism was not disturbed during later events. In addition, Rb-Sr mica ages indicate differential uplift and different minimum ages of Alpine HP-metamorphism in quartzofeldspathic rocks in different tectonic units of the Eastern Rhodope.