Preliminary Geology And Petrography Of Swat Kohistan

ank do not extend on the eastern side which is occupied by diorites of different
appearance and texture. It can thus be assumed that a fault runs along the
stream to the south of Dewangar. Consequently, the western part of the valley
having been shifted to the south as compared to its eastern pert, by more than
s mile. A similar situation is seen in the volcanic rocks near Paloga where the
southern limit extends 1% miles more on the western bank than on the eastern.
However, it is also possible that this difference may be due to the intrusion of
the granites, more on the eastern side. The age of the fault may be post
volcanic and diorites, however, it appears to be older than the Dewangar
Granite which has not been affected.
The volcanic rocks have been inturded by the diorites of Gabral, Deshai,
and the Matiltan Granite. The latter, and the granites of Dewangar, also
intrude the diorites, It is clear from Matsushita's account that the eastern
tributary of Dewangar confluence fiows along the contact of diorites and granite.
Same may also be the case with the western tributary. Because of extreme
relief, the contact between the volcanic rocks and the Basic Complex has not
been carefully studied.
Matsushita and Huzita (1966) pointed out that "the geological structure of
the Western Ka.rakoram is characterized by the zonal arrangement of rock
formasions .................. the boundary between each zone is in some cases
represented by a fault." We have noted a similar zonal arrangement in Swat
Kohistan, although not as perfect as that of their area. The southern part of
Swat Kohistan is occupied by the Basic Complex, extending to the eest and
west. North of this is the zone of metasedimentary and volcanic rocks extending
up to (?) westernDir, Further north are zones of diorites (of Deshai and
Gabral) and Dewangar Granite. All of the plutonic rocks, apparently, are
connected with the Himalayan orogeny.
ECONOMIC GEOLOGY .
In addition to preparing a 'base map, a main purpose of the work in Swat
Kohistan waa the search for economjc minerals. A few days mere also spent
in the Indus Valley to investigate the potentials of the ultrnmafic rocks exposed
near Jijal along the Indue River. Following is the result of the id~esti~ation:
(a) Building a ~ Decorative d Material.
Most of the Swat Kohistsn is covered by plutonic igneous rocks of light to
medium colour which are suitable for building purposes. Special mention can