Post-oligocene Tectono-Eustatic Fluctuations and Their Influence on the Stratigraphy of Eastern Arabia: The Fars Group of the Batina Coast, Oman: The Fars Group of the Batina Coast, Oman

The Fars Group of the Batina Coast of North Oman lies unconformably over Oligocene Asmari Formation (also known as MAM reefs). The group occurs along the low-lying region between the Al-Hajar Mountains and the coast of the Gulf of Oman. The group is divisible into three tectonostratigraphic successions represented by three formations: Sultan Qaboos University (SQU), Suwadi, and Barzaman, in ascending order. The SQU Formation consists of conglomerates, sandstones, and mudrocks with plant imprints in the muddier facies. The lower boundary of the formation is recognized in a well drilled in the Barka area (~35 km west of the SQU campus). This boundary indicates an erosional unconformable contact. A disconformable contact also defines the upper limit of the formation. The formation represents an alluvial fan to braided river system deposits with interfluvial ponds and flood plains. The Suwadi Formation is a carbonate tongue with abundant corals, calcareous algae, larger benthic foraminifera (LBF), echinoids, and mollusks. The LBF fossils indicate Langhian-Serravalian age. The underlying SQU Formation is envisaged to be early Miocene in age. The Barzaman Formation is dominated by pebble- to cobble-size sandy conglomerates with sandstone and mudrock interbeds. These facies accumulated in a fluvio-deltaic environment connected to lacustrine system. The formation consists of a lower unit with rootlets, imbricated clasts, scour surfaces, normal grading, and minor diagenetic (carbonatized) alterations and an upper unit defined by the typical “Barzamanite facies” (ophiolite detrital grains diagenetically altered to carbonate). The age of the Barzaman Formation is considered to be late Miocene to Pliocene in age. The Fars Group has been affected by Pliocene–Pleistocene uplifting and tilting. This resulted in terrigenous Quaternary deposits with marked erosional surface and angular contact.