The Effects of Climatic Variation, Tectonics and Base Level Shifts on the Depositional Framework for the Permian Gharif Formation, Sultanate of Oman

D. Alsop¹

Abstract

The Permian Gharif Formation is a major oil and gas reservoir in the Sultanate of Oman. The subsurface Gharif Formation is divided into three main depositional units (Lower, Middle and Upper Gharif) partially encompassing Depositional Sequences P10 and P20 of Sharland (2004).

Recent studies have looked in detail at the sequence stratigraphic framework of the Gharif Formation and the role of climatic variations and tectonics on the depositional framework. Relative sea level/base level changes have played an important role on depositional styles across the Sultanate of Oman. Deposition of the Gharif Formation followed the final melt-out phase of the Permo-Carboniferous glaciations resulting in a relatively rapid transgression of the Palaeo-Tethys seaway from north-west to south-east during the Lower Gharif times. This transgression is reflected by terrestrial to deltaic environments in the south and shallow marine shoreface deposition in the north-west. Following the P10 maximum flooding surface, a basinward shift of facies resulted in shallow marine carbonates of the Haushi Limestone deposited across much of northern and central Oman.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain