A OPEN PIT MINING AÇIK OCAK MADENCİLİĞİ

1 INTRUDUCTION
The study area is located in the central
part of sanandaj- sirjan metamorphic zone
This zone has a great potential of
hydrothermal deposits such as Agdarreh
(gold), Zarshouran (gold) and Angouran
(mixed sulphide–nonsulphide zinc) (Figure
1). Most of the known deposits exhibit a
well-developed zonal pattern of
mineralization and wallrock alteration that
can be defined by broad variations in major
oxides and trace element concentrations.
These elemental compositions in turn reflect
variations in mineralogical composition of
the altered zones. Most of the hydrothermal
alteration processes produce clay and other
silicate minerals (e.g. argillic and phyllic
zones). Supergene alteration results in the
formation of extensive iron oxide minerals,
giving characteristic yellowish or reddish
color to the altered rocks. These alteration
minerals can be detected by remote sensing
techniques (Abrams et al., 1984; Elvidge &
Lyon, 1984; Amos & Greenbaum, 1989;
Drury & Hunt, 1989).
ASTER data has been used to locate areas
of iron oxides and/or hydrous minerals which
might be associated with hydrothermal
alteration zones. The host rocks that contain
ore deposits of hydrothermal origin always
show the result of interaction with the
hydrothermal fluids that change the mineral
and chemical composition of the rock and
cause the deposition of the ore and related
hydrothermal minerals (Rutz-Armenta &
Prol-Ledesma, 1998).
Aster Image dataset (Terra satellite) with
having suitable spatial and spectral
resolution, has a significant impact on
geological and exploration studies. This
dataset, with suitable spectral resolution in
infrared reflection range -that most minerals
are having absorption spectral charts in it -
provides the possibility of detachment
various alteration types. In addition, In
addition, this sensor having five spectral
bands in the thermal infrared range is
considered a Multi thermal sensor that can
separate Lithological units in this way.
Aster images are classified in 14-band.
The features of sensor images include:
- Visible Near Infrared images (VNIR) with
a ground resolution of 15 meters (3 bands).
- Short Wave Infrared images (SWIR) with a
ground resolution of 30 meters (6 bands).
- Thermal Infrared images (TIR) with 90 m
ground resolution (5 bands) (Fig. 1).
Figure 1. ASTER spectral bands and their
classifications.
In this project, we used the ASTER
images in various band combinations for
extracting geological structures (faults and
lineaments), rock unit types and alteration
associated with gold mineralization.
2 GEOLOGICAL SETTING OF
DARREHASHKI GOLD DEPOSITE
Darehashki gold deposit is located in 55
Km of eastern Golpayegan city, central Iran
(Fig 2). The deposit in one of gold deposits
of occurred in Muteh complex. The complex
were occurred in Sanandaj-Sirjan structuralmetamorphic
zone which has 1500 Km long
and 150 to 200 Km. The Sanandaj-Sirjan
zone related to the creation of the Tethys
ocean and its subsequent destruction during
Cretaceous and Tertiary convergence and
continental collision between the Afro-
Arabian and the Eurasian platesMohajjel et
al., 2003; Agard et al., 2005; Ghasemi &
Talbot 2006; Moritz et al., 2006; Daliran,
2008). The complexly deformed subzone of
the Sanandaj-Sirjan zone, which hosts the
Muteh gold deposits, is distinguished by
abundant greenschist and amphibolite facies
metamorphic rocks (Mohajjel et al., 2003).
Mesozoic and Tertiary sedimentary rocks
overlying Paleozoic sedimentary rocks
predominate in the Muteh complex and are
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