A OPEN PIT MINING AÇIK OCAK MADENCİLİĞİ

3.2.1.3 Propylitic alterations extraction
(epidote - chlorite)
Propylitic zone is outer zones and usually
largest portion of the hydrothermal alteration
and containing internal zones such as argillic
zone. Thus, identification of Propylitic zone
is as the key for experts to finding center
zone of alterations. In this project - for
importance of Propylitic alteration - parts of
the propylitic zone were divided as a result
can be seen in Figure 6c. Propylitic zone
which have separated the blue color in this
picture (Fig 6c)
3.2.1.4 Extraction of silica alteration
Due to the close relation of gold
mineralization and altered silisic zones,
silisic alteration separation helps to identify
potential opportunities for significant gold
mineralization zone.The best reflection of
silica in ASTER images is the range of
infrared wavelength.
Because spatial resolution of these bands
(90 meters) shouldn't expect that recognized
veins of silica with less 90 meter in lithology
units, but it rocks strongly silicified, and
exposed silisic vein with ninety meter wide
or larger can be identified.
Based on satellite data, considerable and
broad siliceous alteration zone appears in
Lithological units. It should be noted that the
separation of silica minerals as well as were
used other algorithms such as LS-fit and
SMACC in ENVI software (Fig 7).
4 CONCLUSION
The use of satellite images during the
early stages of mineral exploration has been
very successful in pointing the
hydrothermally altered rocks. ASTER data
has been used for enhancing the areas with
clay mineral alterations and iron oxide
minerals.
Principal component analysis was done on
the 14 bands and the relevant principal
components are chosen to obtain images that
show iron oxide and hydroxyl minerals (band
combinations technique).
Figure 7. ASTER satellite image with band
combination 1,3,4 in RGB show the
distribution of the silisic zone
Information derived from satellite images
involves the extraction of important
structures such as major and minor faults,
ring structures and clay altrations (propylitic
and argillic) and iron oxide alteration.
The relationship between Exploration and
these phenomena is very close. Most of
alterations occurred along faults or related to
the tectonic structure of the region.
Regarding the relationship between structure
and alteration with mineralization of gold in
this type of deposits, extraction of alterations
and structures increasing possibility of
existence gold mineralization.
In this project was trying with overlapping
faults and alterations associated gold
mineralization in satellite images, the best
areas with potential gold mineralization
identified. Then, these areas controlled with
field operation. Figure 8, was created
overlapping all of extracted data from
ASTER satellite images.
According to this picture, it looks like the
best place for a detailed exploration of gold
at the intersection where the interface
between tectonic structures and the alteration
is extracted from satellite images. Finally, we
can conclude here that remote sensing
technique can be used as a very reliable
method for enhancing the areas with
hydrothermal alteration as a fast and cheap
tool for exploration of orogenic gold
184