TITLE:
Geology of the Aftabrou Polymetallic Deposit, Saveh, Iran
AUTHORS:
Akram Sabzian, Fariborz Masoudi, Hooshang Asadi-Harooni, Mohammad-Hashem Emami, Nima Nezafati
KEYWORDS:
Aftabrou, Polymetallic Mineralization, Calcalkaline, Fluid Inclusion, IOCG Deposit
JOURNAL NAME:
Open Journal of Geology,
Vol.7 No.7,
July
21,
2017
ABSTRACT:
Aftabrou polymetallic prospect is located at the contact of Oligo-Miocene
calcalkaline granodioritic to dioritic and Eocene andesitic to basaltic volcanic
complex in middle section of Urumiyeh-Dokhtar volcanic arc in NW of Saveh
city. Petrographic study indicated that the volcanic rocks are mostly: lava and
tuff. Composition of lavas is mainly andesite and tuffs are mainly composed
of dacite to rhyodacite. Major phenocrysts in these rocks are plagioclase, clinopyroxene,
hornblende and opac minerals. Petrographic and geochemical
studies indicated an I-type granitoid and, calcalkaline magmatism associated
with continental margin of subduction zone. This study determined three
mineralization subzones of 0.2% - 5.3% Cu, 0.02 - 1.31 ppm Au and 1.2% -
3.9% Zn. Fluid inclusion studies on quartzic veins associated with magmatism,
demonstrated that homogenization temperatures of this mineralization
fluid are between 170°C to 330°C, the salinity of the system is between 11.7 to
23.5 weight percent, density of this fluid is 0.8 - 1.1 g/cm3 and is occurred in
depth of less than 1800 m of surface. Fluid inclusion studies suggested that
formation of mineral deposit is simple cooling and mixing with atmospheric
water and type of Aftabrou deposit is IOCG. In this base, it is assumed that
this IOCG mineralization is occurred associate with magmatism that is
formed as a result of Neo-Tethys oceanic subduction beneath the Central Iran
zone which is replaced in the Orumieh-Dokhtar magmatic arc.