Cenomanian-Early Turonian carbonate platform of northern Oman: stratigraphy and palaeo-environments

Abstract

Abstract The Jebel Akhdar and Adam foothills outcrops in northern Oman (Arabian Peninsula) offer the opportunity to study in detail the lateral and vertical changes of a Cenomanian-Early Turonian carbonate platform formed by the Natih Formation (Wasia Group). Eleven sections with less than 5 km offset were logged to express metre-scale lithological and biostratigraphical vertical changes. The first rudist zonation is established, complementing classical benthonic foraminifer and ammonite biozones. Typical Cenomanian rudist association (caprinids and radiolitids) occur in the Natih e-c-d-a (lower part) whereas lower Turonian hippuritid rudists are represented in the upper part of the Natih a. A sedimentological and palaeoecological approach leads to identification and interpretation the facies and discontinuities of the Natih carbonate platform and to a reconstruction of its spatial organization. Application of the concepts of sequence stratigraphy allows interpretation of the units of the Natih in terms of Systems Tracts. An attempt is made to correlate the sequence stratigraphical model to eustatic sea level changes and regional tectonic events. Three palaeoenvironmental models, taking into account bio- and lithofacies, are proposed.