پتروگرافي و پترولوژي مجموعه پلوتونيك جنوب قروه

Petrography and Petrology of the Plutonic Complex of the South of Qorveh

The Qorveh Plutonic Complex(QPC) is in Sanandaj-Sirjan Zone(SSZ), that is located in south of Qorveh about 80 km in NW Hamadan, between 47° 42ʹ and 48° E-longitude and between 34° 50ʹ and 35° 10ʹ N-latitude. Due to post-emplacement tectonism QPC is a multi-pulse structure, containing a large variety of rocks. Three main units have been identified within the QPC based on field observations and mineralogical and geochemical characteristics. Mafic intrusions consist of gabbro-diorites, followed by felsic units that include granitoids and aplites. The QPC lies within the SSZ and emplaced during Eocene-Oligocene times. Microgranular mafic enclaves(MME) and amphibole-rich clots(ARC) are in the QPC. It is composed mainly of metaluminous with I-type affinity and had occurred in volcanic arc to an active continental margin setting. Harker variation diagrams show compositional gap between 59 to 68 wt% Si02 contents and different units derived from a different sources. The combinations of field, petrographic and geochemical data show mafic units derived from mantle source that were enriched by Nb, Rb, Sr, Ba by hyrous fluids and/or malts through crustal contamination.