Chapter 3 Thrusts, extensional faults and fold patterns of the major units

Abstract

Abstract This chapter is concerned with the main faults and folds within the Southeastern Oman Mountains based on available literature. The main, best and most widely exposed thrusts are those related to the SW-directed late Cretaceous obduction of the allochthonous nappes onto the Arabian platform and margin. These thrusts are related to obduction of rocks, which had formed hundreds of kilometres offshore Oman. The thrusts were active from the Cenomanian to the Campanian. Obduction-related thrusts and folds are spectacularly exposed within the rocks of the Arabian platform in the eastern part of the Saih Hatat Dome, including large-scale recumbent cylindrical folds and sheath folds. At least six fold sets can be studied in the Southeastern Oman Mountains. At least two of them had formed prior to obduction and are exposed in the Pre-Permian formations of the Jabal Akhdar Dome. At least three fold sets formed in the course of obduction, while at least one fold set is postobductional in age. Besides the compressional structures, the Oman Mountains expose major post-obductional extensional faults, mostly at the margins of the Jabal Akhdar and Saih Hatat domes. The throw of these faults amounts to a few to several kilometres. Finally, this chapter provides an overview of the enigmatic Batinah Mélange which consists of slivers of Hawasina rocks, resting (unusually) structurally above the Semail Ophiolite.