The Palaeo-Ecology and Geochemistry of Potential Source and Reservoir Microbialites in the Ediacaran-Cambrian Sirab Formation, Sultanate of Oman

Abstract

Background Rationale & Aim; Ediacaran - Cambrian microbial carbonates are known to range from West Africa to Arabia and Pakistan. In the Sultanate of Oman, these microbialites serve as both source rock and reservoir in the Ara Group of the South Oman Salt Basin and host over three-quarters of Oman's petroleum reserves. Unfortunately, given its importance, the Ara Group is only present subsurface and so in-depth studies of it rely solely on well logs, cuttings and cores. Extensive geological field surveying and sampling by the PI in the Al Huqf desert of east central Oman, revealed the presence of an Ediacaran - Cambrian outcrop equivalent of the Ara, subsequently named the Sirab Formation (see Nicholas & Gold, 2012). This project will undertake the first, detailed sedimentological and palaeo-ecological study of the microbial textures and their trace element, REE and stable isotopic geochemistry, with a view to assessing their potential source and reservoir rock properties as surface analogues for the Ara Group subsurface. Can we identify the geochemical signature and ideal Microbialite texture and its depositional palaeo-environment for potential microbial source and reservoir rocks to accumulate?