Stratigraphical and Structural Analyses of the Sagrma (Sagerma) Anticline, Sulaimani Area, Iraqi Kurdistan Region

The Sagrma anticline is a name for two parallel series of mountain peaks that are separated by a deep, wide and elongate valley which has width and length of 2 and 40 km respectively. The valley is called Qopy Qaradagh and it is beautiful picnic area for the people of the nearby Qaradagh town and surrounding villages. The anticline is located 40 kms to the south of Sulaimani city at the boundary between High and Low Folded Zones. Recently the anticline is subjected to intense geological and seismic survey for oil exploration and an oil well is drilled to depth of 3400 m without finding economic oil. The aim of the present study is updating the data about the stratigraphy and structure of the anticline with the critical review of the previous studies. It is also aimed to give the possible reasons for the absence of oil in the anticline. The Kolosh, Sinjar, Gercus (or Khurmala) and Pila Spi Formations are exposed in the core, lower limbs, middle limbs and upper limbs of the inner arc of anticline respectively. The Pila Spi, Oligocene rocks, and Lower Fars, and Upper Fars Formations are exposed along the upper, middle and lower part of the outer arc of the two limbs. The previously described Sagerma and Avanah Formations are not recorded in the present study and this is true for the previous growth strata (as a syn-sedimentary deformation) too. Structurally, the Sagrma anticline is a tight double plunging anticline and its northeastern limb steeper than southwestern one. The anticline is not formed by fault propagation fold as concluded previously but deformed by limb rotation by which a detachment fold is generated. The rotation has intensely deformed the core of the anticline and due to this deformation the possible existed oil is not preserved. The main detachment fold is further deformed into several smaller (parasitic) anticlines which they have either Z or S shape which can be called anticlinorium. The anticline is shorted, in some places, by a large lateral thrust.