Akademik Veri Yönetim Sistemi
V. Jeokimya Sempozyumu, Denizli, Türkiye, 23 - 25 Mayıs 2012, ss.161-162
The Pan-African basement of the
Menderes Massif consists of partially migmatized metasediments, i.e.
paragneisses and metapelites, which were intruded by numerous poly-metamorphic
Precambrian gabbros and syn-to post-metamorphic Pan-African metagranites /
orthogneisses. The relict phases and assemblages attributed to the Pan-African
metamorphic evolution at granulite- and eclogite-facies conditions have been
recognized in the basement. The relicts of granulite facies metamorphism are
represented by orthopyroxene bearing-orthogneisses, pelitic granulites and
metatonalites. In addition to granulite facies metamorphism, widespread
migmatization and anatectic granite generation occur in the basement.
In this study, SHRIMP and LA-ICP-MS were applied to provide timing constraints on the granulite facies
metamorphism and overprinting migmatization, which affected the
Pan-African basement of the Menderes Massif. Cathodoluminescence
imaging of zircons separated from
pelitic granulites occurring in the southern part of Ödemiş-Kiraz submassif (SE
of Tire) reveals that many of the
grains contain unzoned and/or planar zoned overgrowth textures
representing metamorphic growth on inherited cores. Textural relationships
clearly reveal that granulite facies unzoned zircon overgrowth must have
occurred prior to planar zoned overgrowth reflecting crystallization from
anatectic melts. SHRIMP analyses of unzoned overgrowths yield concordia age of 582.0 ± 5.3 Ma. Whereas, planar zoned zircon overgrowths
occurring in the outermost parts of the crystals gave concordia age of 565.0 ± 5.4 Ma.
LA-ICP-MS analyses of unzoned overgrowths yield concordia age of 582.0 ± 5.3 Ma. The zircons separated from metatonalite at the centre of Ödemiş-Kiraz submassif (northeast
of Birgi area) show that many of the
grains contain magmatic crystallization texture and unzoned overgrowths
representing the high temperature metamorphism. Oscillatory zoned magmatic
zircons yielded a concordia age of 591.0 ± 6.9 Ma and unzoned overgrowths occurring in the outermost parts of the magmatic zircons gave a concordia age of 578.4 ± 8.2
Ma by LA-ICP-MS U-Pb analyses. Thus, c. 590 Ma is
interpreted the crystallization age the protolith of metatonalite. A 580-585 Ma is interpreted the age of
granulite facies metamorphism and 565 Ma can be accepted as the age of
migmatization affected the basement series. All ages coincide with final amalgamation
processes resulting in the formation of the Gondwana super continent as a
consequence of the closure of the