Abstract

The analysis of foraminifera and radiolaria in 3000 carbonate and 150 siliceous rock samples from the Oman Mountains results in revision of the existing stratigraphy and supports the definition of new units. In the Hawasina allochthonous unit the main results are as follows: (i) Permian bedded chert exists near the base of the sequence and is thus the first Permian bedded chert occurrence reported from the Tethyan region); (ii) an important volcanic event is dated as Triassic; (iii) bedded chert horizons are dated as Liassic; (iv) the thick turbiditic sequence has been divided into several units of Middle and Late Jurassic age. In the Samail ophiolite: (i) the ages of four tectonic episodes were established from the beginning of oceanic spreading (Albian—Early Cenomanian), to the obduction of the ophiolitic nappe (Campanian).