Spatial arrangement of fold types in the Zagros Simply Folded Belt, Iran, indicated by landform morphology and drainage pattern characteristics

Authors

Caroline M. Burberry, University of Nebraska-LincolnFollow
John W. Cosgrove, Imperial College LondonFollow
Jian Guo Liu, Imperial College London

Date of this Version

2008

Comments

Published in Journal of Maps, 2008, 417-430; http://www.journalofmaps.com

Abstract

The spatial arrangement of fold types within the Zagros Simply Folded Belt was analysed using satellite images, a digital elevation model and a digital drainage network. Distinct fold geometries, principally fault-bend folds and detachment folds, can be identified by characteristic interactions with streams flowing SW from the High Zagros Mountains into the Persian Gulf. In addition, the morphology of the landforms is reflected in the minor channel patterns across the folds. This morphology can also be categorised using geomorphic indices, L/W ratio and symmetry index. The distribution of fold types is shown for the region N27°-N30°, E50°-E54° at a scale of 1:750,000. Anomalously long, high-aspect ratio folds, coincident with topographic steps, were inferred to be fault-bend folds, crossed by multiple wind gaps, overlying major thrust faults. These faults formed sequentially as the deformation front migrated from the collision zone towards the SW, causing diversion of stream channels. Movement up thrust ramps created fault-bend folds behind which serial detachment folding developed in the cover.