Taxonomical and biostratigraphical notes on Nummulites of Darnah Formation at Daryanah-Al Abyar area, Cyrenaica, NE Libya.

Abstract

Darnah Formation at Wadi Ekhil in Daryanah- Al Abyar area, Al Jabal al Akhdar, Northeast Libya has been subjected to micropaleontological and biostratigraphical analyses based on larger foraminifera "Nummulites" which has largely used as a time marker in the Tethyan region (Circum-Mediterranean). Taxonomical measurements were performed during this study from which the following five species were identified, Nummulites gizehensis, N. lyelli, N. beaumonti, N. striatus and N. sp. The studied sections assigned to the i) N. gizehensis biozone Late Eocene "Late Lutetian" age due to the acme occurrence of the zonal marker species N. gizehensis; and ii) N. lyelli biozone Late Eocene “Biarritzian" due to the total range of the zonal marker species N. lyelli. The concerned nummulites-bearing sections of Darnah Formation indicate an inner neritic environment of bank settings as indicated by A/B ratio.