Geochemistry and Tectonomagmatic Setting of Plutonic Rocks in Ureh Complex (North West of Ardestan City)

The Ureh area is located in Urumieh – Dokhtar magmatic assemblage (UDMA). This complex show gabbro to granite composition range and their magmas penetrate in Eocene folded volcanic and pyroclastic rocks. The change in abundance of minerals such as pyroxene, magnetite, amphibole, biotite, plagioclase and feldspar in the volcanic rocks, indicates the successive process of differentiation in intermediate magma; the same change created variation in lithology. Petrographic features as well as major and trace element geochemistry appear to suggest a common dioritic parental magma for all rock types. The Ureh plutons are characterized by enrichment in(LILE), moderate depletion in(HFSE) and enrichment of LREE compared to HREE on spider diagrams. The Ureh complex rocks show calc alkaline to high calk alkaline and meta aluminous nature. Granitoid rocks are High temperature I- type and Syn- Collision in geotectonic diagrams. Considering of some evidences like locating of these intrusive in Urumieh-Dokhtar magmatic belt, the normative hyprestene, calkalkaline nature, the anomalies in REE and other trace elements in spider diagrams, plating of more basic samples in calk alkaline and island arc setting, it seems the formation of these intrusives are belong to subduction zone.

Keywords:

Geochemistry , plutonic rocks , Ureh complex , Tectonomagmatic Setting