Biostratigraphical Study on Selected Water Wells Al Jabal al Akhdar, Libya

Twelve subsurface boreholes (water wells, maximum depth reaches 650m) have been stratigraphically studied and micropaleontologically investigated, which are located in an area extended from Battah to the vicinity of Darnah in the second escarpment of Al Jabal al Akhdar region, Northeast Libya. The microfossils (foraminifers and calcareous nannofossils) contributed directly in determining the age of the aquifers via in-situ diagnostic taxa, and indirectly via stratigraphical position and lateral correlation in relation with the neighboring wells. One Miocene biozone, two Oligocene biozones, two Eocene biozones and one Cretaceous biozones of foraminifers are recognized during this study. Meanwhile, only Eocene and Cretaceous calcareous nannofossils biozones are recognized.