Oligocene and Miocene Rock Beds in Mamlaha anticline, Chamchamal town, Sulaimani city- Kurdistan region/ Iraq

Abstract

Previously, the Oligocene rock beds in the Mamlaha anticline have neither mentioned nor
 proved. There are some selected sections that detected during field surveys but did not verified
 weather belong to Oligocene- Miocene ages or not. Through this research, it is proved that they are
 composed of Oligocene and Miocene rock strata. They are well-known as excellent rock reservoirs
 for hydrocarbon accumulation in Kurdistan region and Iraq as a whole.
 Field survey and stratigraphic study with microfacies analysis showed that nearly 37 meter of the
 rock units from Mamlaha anticline (Mamlaha, Khwelin and Pungala sections) are representing
 these formations; Bajwan Formation (Middle Oligocene), Anah and Ibrahim formations (Late
 Oligocene) ages, Serikagni, Euphrates and Dhiban formations (Early Miocene) and Jeribe
 Formation (Middle Miocene) ages respectively.
 The contact between Bajwan and Anah is unconformable; the Lower contact of Bajwan Formation
 is not exposed in each of the section. Ibrahim Formation however not exposed as well beds of marly
 limestone; it shows as pocket of marly limestone, but it sandwiched between Bajwan and Anah
 formations and shows no clear boundary.
 The upper contact of Anah Formation is separated from Euphrates Formation by 2 meters of green
 marl which indicates abrupt change in the lithology. The upper contact of Euphrates shows
 unconformity, while Dhiban Formation is unconformably underneath the marly sandy bituminous
 limestone of Jeribe Formation; Jeribe Formation is also unconformably lies beneath the claystone of
 Fatha Formation.