a conglomerte bed as a possible lower boundary - Professor Kamal ...

CHAPTER ONE
INTRODUCTION
during the Pliocene time. He added that the regional structure of the area trends with
the Zagros, NW-SE direction, though several changes in the direction have been
recorded (Fig.1.2). Structurally, the studied area is located within the Thrust Zones
(Buday and Jassim, 1987). The same authors, in their tectonic subdivision of Iraq put
the studied area in the Qulqula-Khuakurk Subzone. The area is characterized by
obscured anticlines and synclines which have been stacked together as very thick
and tight successions which were overturned toward southwest. Most of these
structures suffered from thrusting, therefore, Stocklin, (1968) called the studied area
“Crushed Zone” this is because it is highly deformed on large scale and small scale,
even one can see fracture, fault and fold under polarizing microscope. According to
Karim, (2003); Karim and Surdashy, (2005), Baziany, (2006), the deformation and
development of the studied area mainly began from Campanian. They added that at
this age the continental part of Iranian and Arabian plate is collided with Iranian and a
Foreland basin is formed. By continuous advancing (thrusting) of the foreland and
hinterland of the Iranian plate the sediments inside the basin is progressively
deformed and accumulated as accretionary prism. The deformations and
sedimentation were continuous until the end of Tertiary, by which the studied area
gained the present geological setting which is now highly modified by weathering and
erosion.
The studied area consists, at least, of four large horsts which are separated by
three grabens (Fig.1.3). The first horst is located in the area around Halabja town
while the second one is located in the north east of Sulaimani city in the area
between Said Sadiq and Chuarta towns. On this horst, the Jurassic rocks are
exposed near the northeastern boundary (Fig.1.3). This horst is bounded by two
transverse normal faults from northwest and southeast. The former fault is described
by Karim, 2005) which is located in the east of Chuwarta town while the latter is
found in this study, and it passes through Said Sadiq town and Kaolos village. The
third horst is located between Mawat and Qaladiza towns.
The grabens are consisting of low lands (plains) such as Sharazoor plain (eastern
part), Mawat and Chuwarta low lands and Sangasar Plain. In this area, the Qulqula
Formation acts as thrust fault inside the graben while is perform as reverse faults on
the horsts (Karim et al, 2007) (Fig.1.3).
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