Temporal–spatial distribution and tectonic setting of porphyry copper
deposits in Iran: Constraints from zircon U–Pb and molybdenite
Re–Os geochronology
Mehraj Aghazadeh
a,
⁎, Zengqian Hou
b
, Zahra Badrzadeh
a
, Limin Zhou
b
a
Department of Geology, Payame Noor University, Iran
b
Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, People's Republic of China
abstract article info
Article history:
Received 30 April 2014
Received in revised form 4 March 2015
Accepted 7 March 2015
Available online xxxx
Keywords:
Geochronology
Ore forming episode
Tectonic setting
Porphyry copper deposit
Iran
Porphyry copper deposits (PCDs) in Iran are dominantly distributed in Arasbaran (NW Iran), the middle segment
of the Urumieh–Dokhtar Magmatic Arc (UDMA), and Kerman (central SE Iran), with minor occurrences in east-
ern Iran and the Makran arc. This paper provides a temporal–spatial and geodynamic framework of the Iranian
porphyry Cu (Mo–Au) systems, based on geochronologic data obtained from zircon U–Pb and molybdenite
Re–Os dating of host porphyritic rocks and molybdenites in 15 major PCDs. The dating results define a long
metallogenic duration (39–6 Ma), and suggest a long history of tectonic evolution from the accretionary orogeny
related to early Cenozoic closure of the Neo-Tethys Ocean to subsequent collisional orogeny for the Iranian por-
phyry copper systems.
The oldest porphyry mineralization occurred in the eastern part of Iran after the closure of a branch of the Neo-
Tethyan (Sistan) Ocean between the Lut and Afghan blocks in the late Eocene (39–37 Ma). This was followed by
mineralization in the Kerman porphyry copper belt over a time interval of about 20 m.y., where two metallogenic
epochs have been recognized, including late Oligocene (29–27 Ma) and Miocene (18–6 Ma). The Bondar-e-
Hanza deposit formed in the late Oligocene, while and the remaining dated deposits belong to Miocene epoch.
According to the deposits' characteristics and their ages, the Miocene epoch can be divided into early, middle,
and late stages. The Darreh Zar, Bakh Khoshk, Chah Firouzeh and Sar Kuh deposits formed during the early–mid-
dle Miocene. The largest porphyry deposits occur in the middle stage during the middle Miocene (14–11 Ma) and
include the Sar Cheshmeh, Meiduk, Dar Alu and Now Chun deposits. These deposits were formed during crustal
thickening, uplift, and rapid exhumation of the belt. The final stage of porphyry mineralization occurred during
the late Miocene (9–6 Ma), and formed the Iju, Kerver, Kuh Panj and Abdar deposits.
There were two porphyry mineralization stages in the Arasbaran porphyry copper belt in NW Iran, including an
older late Oligocene (29–27 Ma) and a younger early Miocene (22–20 Ma) events. The Haft Cheshmeh deposit
belongs to the older stage, and the world-class Sungun and Masjed Daghi deposits formed during the early
Miocene.
In the middle segment of the UDMA (Saveh–Yazd porphyry copper belt), PCDs formed during middle Miocene
time (17–15 Ma). The geochronological results reveal that the porphyry mineralization moved from the north-
west to southeast of UDMA over the time.
Our dating results, combined with the possible late Eocene–Oligocene timing for collision between the Arabian
and Iranian plates, support a model for Iranian PCD formation by partial melting of previously subduction-
modified lithosphere in a post-subduction and post-collisional tectonic setting.
© 2015 Elsevier B.V. All rights reserved.
1. Introduction
Porphyry copper systems are mainly developed at convergent plate
margins, including continental margin and island-arc settings (Sillitoe,
2010, and references therein), where subduction of oceanic crust is
related to arc-type magmatism that generates most of the hydrous, ox-
idized upper crustal granitoids genetically related to ores. In these mag-
matic arcs, deformation can be very complex, and porphyry copper
deposits can form in a variety of tectonic settings (Richards, 2009). Por-
phyry copper deposits in the Andes are classic deposits that are generat-
ed in the continental arcs in response to flattening of the subducting
oceanic slab and associated crustal thickening and block uplift (Bissig
et al., 2003; Kay et al., 1999; Perelló et al., 2003; Richards et al., 2001;
Ore Geology Reviews xxx (2015) xxx–xxx
⁎ Corresponding author.
OREGEO-01464; No of Pages 22
http://dx.doi.org/10.1016/j.oregeorev.2015.03.003
0169-1368/© 2015 Elsevier B.V. All rights reserved.
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Please cite this article as: Aghazadeh, M., et al., Temporal–spatial distribution and tectonic setting of porphyry copper deposits in Iran: Constraints
from zircon U–Pb and molybdenite..., Ore Geol. Rev. (2015), http://dx.doi.org/10.1016/j.oregeorev.2015.03.003