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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXX V, Part B7. Istanbul 2004
Mineral Mapping Flowchart
Understanding the distribution type of spectral
reflectance data for each band interval
+
Calculation of the descriptive statistics
of the reflectance data
Defining the maximum and minimum values
for the band intervals
Band
Rationing
Calculation of the upper and lower limits
of the band ratios
mi
Filtering the band ratios according
to the predefined limits
——— ————
Add / Remove Band
Ratios
Final Mineral
Map
Figure 6. Flow chart of the mineral mapping technique.
Yenipinar e |
]i
Ye x CH 4
X ^"
w e
%
T À
/ NS |
1
\ : PET |
À y |
|
JJ |
i |
Altunhisar |
0 25 5 10 Km
RU REN |
Figure 7. Band4/Bandl ; Band4/Band7 ; Band5/Band? are filtered for
Kaolinite according to the upper and lower limits. Passed values are
displayed as black pixels.
3. CONCLUSION
All of the conventional methods agree that the volcanic eruption
centers of Tepekóy, Keciboyduran and Melendiz volcanic
complexes are highly altered having both clay and iron oxide
minerals and away from the centers, iron oxide zone is mapped in
PCA and Ls-fit. techniques.
The proposed method aimed to map the alteration minerals
individually. Statistical method of filtering the band ratios is tested
and found to be very accurate with the vegetation data. For every
mineral 30 combinations of band ratios are present. Bands that are
likely to give high ratios are selected for the filtering process.
Although some of the previously known clay altered areas could
not be mapped, in general the results were coincident with the
previously applied methods. Detailed mineral maps are obtained
as outputs of this method.
389
The resulting mineral maps are grouped for ironoxide minerals
and clay minerals separately. Main ironoxide-rich areas are
mapped in Tepekóy, Melendiz and Keciboyduran volcanic centers
and along a north-south trending linear path in the west of
Keciboyduran volcanic center. This linear concentration overlaps
with the buried fault in the same area (Yetkin, 2003).
!
Figure 8. Areas that are both clay and iron oxide altered by mineral
mapping method.
Clay-rich areas are mapped in Melendiz volcanic center. in the
Tepekóy volcanic center, in the northwest flanks of Hasandag
complex and a small area between Keçiboyduran and Hasandag
volcanic complexes directed along Tuzgólü fault zonc.
Melendiz volcanic center is mapped as both clay and ironoxide
altered, where small areas of Tepekóy and Hasandag volcanic
complexes are mapped as ironoxide altered only.
However there are significant intersections with the conventional
methods’ outputs and mineral mapping method outputs, Tepekoy
volcanic center, mapped as both clay and ironoxide rich in
classical ways, is mapped as more fresh by the spectral analysis
method (Fig. 8).
REFERENCES
Aydar, E., Gündogdu, N., Bayhan, H. and Gourgaud, A., 1994.
Volcano-structural and petrological investigation of the
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Beane, R.E., 1982, Hydrothermal alteration in silicate rocks,
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Geology of the Porphyry Copper Deposits, Southwestern North
America: Tucson, Univ. Ariz. Press, Chapter 6.
Besang, C., Eckhardt, F.J., Harre, W., Kreuzer, H., Müller, P.,
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Eruptivgesteinen der Tiirkei. Geol. Jb. B 25, 3-36.
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using a complete band shape least-squares fit with library
reference spectra. In R. O. Green (Ed.), Proceedings of the second
