NEOTECTONIC MOVEMENTS IN DARBANDI BAZIAN AREA, SOUTHWEST OF SULAIMANIYAH CITY, NE IRAQ

Abstract

The northeastern part of Iraq is known to be tectonically an active area due to its position in the northeastern marginal part of the Arabian Plate, which is in collision with the Eurasian (Iranian) Plate. Therefore, the whole area referred to the High Folded Zone is consequently active. The activity, however, is not uniform; locally more active areas do exist causing Neotectonic movements. Darbandi Bazian Gorge that is located southwest of Sulaimaniyah city, NE Iraq suffers from Neotectonic movement, being more active from near surroundings. The gorge is located within the Pila Spi Formation that consists of well bedded, hard limestone and dolostone with very rare marl intercalations; its thickness is about 120 m. The Pila Spi Formation forms a continuous ridge, few hundred kilometers in length that represents the boundary between the High Folded and Low Folded Zones, the former being in the north.The area had suffered from Neotectonic movement, which is indicated by the existence of large alluvial fans, southwards of Darbandi Bazian Gorge, the fans are formed by a single perennial stream that was previously flowing out of the gorge towards south. The older alluvial fan is now inactive, because the stream is divided into two parts; the divide point being on the top of the Pila Spi Formation that forms a high ridge, about 200 m and dips southwestwards. Part of the stream; called Chamai Bawa Fany flows southwards across the alluvial fan, whereas the other part; Tainal Stream flows northeastwards then turns southeastwards; parallel to the ridge of the Pila Spi Formation and continues its direction for about 20 Km, then turns southwestwards and crosses the same ridge in another gorge; called Basara, which is parallel to Darbandi Bazian Gorge.The abandoned alluvial fan, the presence of old fan near Cham Chamal town, the division of the stream into two opposite parts, the abnormal trend and course of Tainal Stream, and the abnormal shape of the Darbandi Bazian Gorge are good indications for uplifting Neotectonic movement in Darbandi Bazian area, which is estimated to be during the late Holocene.