40 Ar/39/Ar dating and cooling history of the Pangeon granitoids, Rhodope Massif (Eastern Macedonia, Greece)
(EN)
ELEFTHERIADIS, G.
FRANK, W.
PETRAKAKIS, K.
The Pangeon granitoids are distinguished into two pétrographie types with sharp contacts: (a) heterogranular, medium- to coarse-grained, hornblende+biotite- bearing porphyritic tonalités and granodiorites (PTG), and, (b) equigranular, medium-grained, biotite±muscovite-bearing granodiorites and granites (MGG). Dark-coloured, medium-grained monzodioritic enclaves occur in PTG rocks. Hornblende 40Ar/39Ar spectra from the PTG rocks yielded cooling ages of 21.7±0.5 Ma to 18.8±0.6 Ma. With the exception one sample, the corresponding hornblende ages from enclaves coincide well with the above ages. The age of 21.7±0.5 Ma is considered as the lower limit for the PTG rocks emplacement. Muscoviteplateau ages of c. 15.7±0.5 Ma and total gas biotite ages of 15.2±0.4 Ma to 13.8±0.5 Ma from the studied rocks, constrain the cooling history of the Pangeon granitoids (with some local variations) in the range 430 - 300Ί C.
(EN)
