Deducing the Lateral Growth of Anticlines using Drainage Analysis and Geomorphological Features

Abstract

The Low Folded Zone in Iraq is an active tectonic area witnessing different evidences for Neotectonic activities, among them are the lateral growth of Jambour, Pulkhana, and Qumar anticlines which are part of anticlinal series in the Low Folded Zone and Zagros Fold–Thrust Belt. The exposed rocks are of Middle Miocene – Pleistocene age overlain unconformably by different types of Quaternary sediments which show different indications for lateral growth. Three anticlines are dissected by tens of different size valleys crossing the anticlines forming water gaps and wind gaps which are good indication for the anticlines lateral growth. We studied the lateral growth of three anticlines using different means of qualitative analysis of satellite imagery and digital topography and ArcGIS technique. The anticlines lateral growth was mainly manifested by the drainage system and patterns which exhibited strange courses during dissecting the three studied anticlines. Moreover, the main streams deposited alluvial fans during Early Pleistocene and even Early Holocene which were also influenced by both lateral and vertical anticlines growth. Their abnormal shapes, abandoned fans and streams were among indications. We measured different geomorphological indices which indicated tectonic activity of the study area.