Oxfordian Benthic Foraminifera and Ostracods from the Hanifa Formation (Hawtah Member), Central Saudi Arabia

Abstract

The Hanifa Formation in Saudi Arabia consists of mostly carbonate units of Late Jurassic age and is well exposed along the Tuwaiq Mountain escarpment. Micropaleontological analyses of samples from three outcrops have revealed the presence of benthic foraminifera and ostracods. The study of fossil faunas from the Hawtah Member, has led to the identification of six foraminiferal species: Alveosepta (Redmondellina) powersi, Oolina globosa, Nautiloculina oolithica, Kurnubia palastiniensis, Pseudomarssonella cf. maxima, Lenticulina sp. and two ostracod species: Hutsonia asiatica and Cytherella cf. umbilica. The survey of species covered in this research suggests that they indicate a predominantly euryhaline to polyhaline marine setting, possibly with a slightly brackish influence and deposited in a supratidal environment, suggesting a progressively shallowing environment on the inner shelf with intermittent shoal complexes.