Late Cretaceous and Paleocene Ostracods from the Waha and Heira Formations of the Sirte Basin, Libya

Geology, Paleontology

Mohamed-Saleh, Ali El Sogher

University:University of Glasgow

关键词: Geology, Paleontology;   

Others  :  http://theses.gla.ac.uk/78289/1/11008021.pdf

来源: University of Glasgow

【 摘 要 】

The aim of the project is to study the taxonomy of the ostracods of the Upper Cretaceous (Waha Formation), and Lower Paleocene (Heira Formation) in the Sirte Basin, Libya, and to discover their value in correlation between wells in Libya, and between Libya and adjacent regions. No study has previously been carried out on the ostracods of these formations. The material studied was mainly ditch cuttings with a few core chips from the Waha and the Heira Formations of wells E12, E46, and E57 in the Raguba Oil Field of the Sirte Basin, Libya. Thirty-five genera, seventy-three species and two subspecies have been recorded among which twenty-five species are proposed as new; seventeen species have previously been described; thirteen can be closely compared with described species; and the remainder left under open nomenclature. Many of the species previously described have a wide range of distribution in the Upper Cretaceous and the Paleocene of North Africa, West Africa, and the Middle East. Nine species make their first downhole appearance in the Waha Formation, of which only four species are previously described. Cristaeleberis fornicata Bassiouni is important because it is only known from the Maastrichtian in other areas. The presence of certain species such as Paracosta pervinquieri (Damotte & Donze) in the Heira Formation suggests that it is probably Early Danian in age. A brief review of the palaeoecology and palaeobiogeography of the investigated ostracod taxa has been described. The generic and specific composition of the overall fauna suggests deposition at mid-shelf depths. A brief review of Paleocene faunas for considering the palaeobiogeographical purposes is undertaken, and the need to take into account the presence of the Lower Paleocene hiatus in many localities in North Africa and the Middle East. In general the Paleocene ostracods show a relationship with other parts of North Africa as well as with West Africa, Jordan, and Saudi Arabia.