Open Access40 Ar/39/Ar dating and cooling history of the Pangeon granitoids, Rhodope Massif (Eastern Macedonia, Greece)
Author(s) -
Georgios K. Eleftheriadis,
Wolfgang Frank,
Konstantin Petrakakis
Publication year - 2001
Publication title -
deltio tīs ellīnikīs geōlogikīs etaireias/deltio tīs ellīnikīs geōlogikīs etaireias
Language(s) - English
Resource type - Journals
eISSN - 2529-1718
pISSN - 0438-9557
DOI - 10.12681/bgsg.17116
Subject(s) - hornblende , biotite , porphyritic , geology , geochemistry , massif , muscovite , paleontology , quartz
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.