A OPEN PIT MINING AÇIK OCAK MADENCİLİĞİ

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largely covered by Quaternary rocks, as
shown in Figure 1 (Moritz et al., 2006).
The Muteh complex consists of 9 gold
deposits for gold mineralization that Chah
Khaton and Senjedeh are extracted since
1991, as depicted in Figure 2 (Moritz et al.,
2006). The rocks in the vicinity of the Muteh
deposit are predominantly schist and gneiss,
subsidiary amphibolite and quartzite, and
local marble and magnetite horizons (Thiele
et al., 1968; Paidar-Saravi, 1989).
Figure 2. Location of the Muteh complex and
the Iranian famous hydrothermal deposits at
the intersection of the Sanandaj–Sirjan
metamorphic zone with magmatic belt of
Urumieh–Dokhtar. Simplified tectonic map
of southwestern Iran, showing the
subdivisions of the Sanandaj-Sirjan tectonic
zone (Stöcklin, 1968 and Daliran, 2008)
The schist contains mainly quartz, biotite,
chlorite, and muscovite. The granitic rocks
emplaced in the metamorphic complex in the
immediate vicinity of the Muteh gold mine
are mediumgrained biotite and two-mica
leucogranites, which locally can be
extremely rich in quartz and feldspar and
mica poor (Thiele et al., 1968). Hornfelsic
rocks result from contact with the granite
(Paidar-Saravi, 1989).
Paidar-Saravi (1989) also described a
range of different meta-volcanic rocks,
including rhyolitic, dacitic, and andesitic tuff
and lava, which were already described in
internal reports of the Geological Survey of
Iran (Alavi- Tehrani, 1980, cited in Paidar-
Saravi, 1989). According to Paidar-Saravi
(1989), these rocks have a granolepidoblastic
texture with quartz and feldspar
forming a mosaic intergrowth and mica and
chlorite defining the foliation. Pyrite and
locally larger crystals of are also mentioned.
Paidar-Saravi (1989) described the metavolcanic
rocks as interlayered with schist but
provided no further textural evidence that
they are tuffs or lavas. During our fieldwork,
we did not recognize any primary textures,
and these rocks cannot be distinguished from
the other metamorphic rocks in the area.
Therefore, we refer to them as gneiss or
schist. Rachidnejad-Omran et al. (2002) also
mentioned the presence of meta-rhyolite and
meta-volcanic tuff, in spatial association with
higher gold grades, but with no additional
evidence for this rock classification. They
interpreted the meta-rhyolite together with
the amphibolite as a bimodal volcanic suite
and the host schist and gneiss as an early
Paleozoic (to Late Proterozoic) volcanosedimentary
complex.
Hydrothermal alteration associated with
the gold occurrences is characterized by
intense, pervasive bleaching of the host
rocks. In areas where alteration is less
intense, it can be seen that the bleaching
occurs along small fractures crosscutting the
sub-horizontal foliation of the host rocks
(Moritz et al., 2006). It consists of silicified
rock with microcrystalline to crystalline
quartz, fine-grained muscovite, pyrite,
dolomite-ankerite, and albite overprinting the
metamorphic minerals of the host rocks.
Lithological units in Dareh-Ashki deposit
concluded green schist, granite and
hornfelse. Some parts of the deposit covered
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