The northeastern part of Iraq; the Kurdistan Region is a mountainous area with rough topography that increases in relief differences and roughness towards north and northeast. Among those mountains is Pera Magroon with highest peak at elevation of 2773 m (a.s.l.) and relief difference with the southern plain of about 1000 m. Pera Magroon Mountain represents a double plunging anticline trending NW – SE; with many minor complications on both limbs. The oldest exposed rocks in the anticline belong to Late Jurassic, whereas the rocks of the Qamchuqa Formation form the carapace of the mountain. The southwestern limb is steeper than the northeastern one; almost being vertical. A very old and large landslide had occurred along the southwestern limb of Pera Magroon anticline ended near Qara Chattan village; therefore, it is called “Qara Chattan Landslide”. The landslide is a rock slide type with rectangular tongue-shaped and crescent-like toe area. The slid blocks belong to Qamchuqa Formation, range in size up to 3 m3; but the average size is about 1 m3. The Qara Chattan Slide had happened; most probably above an area that was originally an old alluvial fan. The slid mass has swiped the alluvial fan sediments as the large blocks were moving in very high speed down the slope during the sliding. However, on both sides of the landslide the remnant of the alluvial fan sediments can be seen in form of longitudinal and narrow masses; like embankments. To estimate the age of Qara Cahttan Landslide, the exposure dating method is used depending on the size, depth and length of the existing valleys, the age of the nearby landslide and alluvial fans, and historical data acquired from archaeological site. Accordingly, the age of the landslide is estimated to be few thousand years; during the Holocene.
Keywords: Landslide, Alluvial fan, Pera Magroon anticline, Kurdistan, Iraq