Application of basic remote sensing in Geology. This presentation tries to discriminate the lithology in the Landsat-7 scene located Karachi West. Although other enhanced methodology available to discriminate the rock types, here just a band ratios and simple band combination used for lithology identification.

2. "Say:” Travel in the land and see how (Allah)
originated creation, and then Allah will bring
forth (resurrect) the creation of the Hereafter
(i.e. resurrection after death). Verily, Allah is
able to do all things."
(Surat Al-'Ankabut: 20)

3. OBJECTIVE

Identify the following on satellite image of
Landsat 7 :
 Discrimination
between different rock types.
 Identification of limestone.
Hands on practice of software ENVI 4.7 &
Arc GIS 9.3
 Result & Conclusion.


4. METHODOLOGY
 Literature
review
Acquisition of the Landsat 7 data.
 Layer stacking of image.
 Index processing
 Band Combination & Band Ratios
application.
 Thematic maps using Arc GIS.


5. INTRODUCTION
GEOLOGICAL MAPS
 A geological map is a special-purpose map made for
showing subsurface geological features. Geologic maps
are often superimposed over a topographic map (and at
times over other base maps) with the addition of a color
mask with letter symbols to represent the kind of
geological unit, fault lines, strike and dip symbols, and
various additional symbols (e.g. mine or mineralization)
as indicated by the map key.

Geological maps provide a plan view of an area. They are
produced by a combination of aerial surveys and on-theground mapping. They show rock types appearing at
Earth’s surface, as well as the orientation of rock strata.

6. STUDY AREA
The targeted area is
located
at
the
southern
end
of
Kirthar Fold Belt
which in turn is
located to the west of
the Karachi city. The
area
belongs
to
Survey of Pakistan
topographic
sheet/map No. 35
L/13.

7. LANDSAT 7 IMAGE OF STUDY AREA (2009)

8. FALSE NATURAL COLOR COMPOSITE BANDS 7,4,2

9. VEGETATION ENHANCEMENT BANDS 4,3,2

10. BANDS 7/4, 7/5, 7 IN RGB FOR LIMESTONE

11. BANDS 7/4, 7/5, 7 IN RGB FOR LIMESTONE

12. GSP GEOLOGICAL MAP

13. UNSUPERVISED CLASSIFICATION

14. RESULT

Ratios of Landsat TM bands played an important role in
Landsat image interpretation and identification of different
lithologies.

Landsat data also revealed to be capable of depicting lineaments
during geological mapping

The unsupervised classification by using all seven bands has
attested positive in identifying the major rock types present in the
study area.

Interesting features like these support the need of ground
truthing purposely for clearing doubts emerged in the analysis.

15. CONCLUSION

Band ratios and composite images have played a great
role in discriminating and identifying different rock types.

Results from this study suggest that large part of
geological mapping can be done through the use of
Landsat data as an alternative approach

Additionally they are cheap compared to the geological
data, sometimes these data are free of charge.

Moreover, to the third world countries, the approach is a
solution to the unavailability of fund which has been an
ordinary song from their national governments.

16. THANK YOU