Original paper
Petrological and geochemical constraints on the evolution of the Cheshmeh-Sefid granitoid complex of Golpayegan in the Sanandaj-Sirjan zone, Iran
Davoudian, Ali Reza; Hamedani, Ali; Shabanian, Nahid; Mackizadeh, Mohammad-Ali
Neues Jahrbuch für Mineralogie - Abhandlungen Band 184 Heft 2 (2007), p. 117 - 129
published: Oct 31, 2007
DOI: 10.1127/0077-7757/2007/0085
ArtNo. ESP154018402001, Price: 29.00 €
Abstract
The Cheshmeh-Sefid granitoid complex, hosted by metasedimentry and meta-igneous rocks, north of Golpayegan, Sanandaj-Siran zone of Iran, is a heterogeneous pluton that comprises mainly quartz-monzonite, quartz-syenite, granite and syenite rocks. Geochemically, the granitoids are mostly peralkaline to metaluminous. They have similar trace element abundances over a range of SiO2 from 57 to 72.4 wt.%, and have a distinctive A-type chemistry characterized by high contents of Na2O + K2O, Nb, Zr, LREE and low MgO. The P-T conditions of crystallization of the granitoids were determined from amphibole-bearing samples using amphibole-plagioclase thermometry and Al-in-hornblende barometry. Aluminum-in-hornblende geobarometry indicates crystallization pressures of about 5 to 6 kbar; corresponding to intrusion depths of 17 to 20 km. Hornblende-plagioclase geother-mometry indicates hornblende crystallization temperatures of 750 to 790 °C. Also, the Zr saturation temperature based on zircon solubility reflects a mean temperature of 776 °C.
Keywords
a-type granitoid • sanandaj-sirjan zone • iran • geothermobarometry • geochemistry