DOI: 10.5176/2251-3353_GEOS14.45
Authors: Ahmed M. Muftah
Abstract: The data base of this paper is came from five unique surface exposures (Jardas al Abid school, Ras al Hilal cliff, Wadi al Qalah, Wadi al Athrun and Uwayliah quarry) and subsurface well D1-NC152 from Al Jabal al Akhdar "Cyrenaica" NE Libya. The recovered foraminifers are identified and used herein to construct a comprehensive biozonation for the concerned Upper Cretaceous/Lower Tertiary successions.
Eight Cretaceous foraminiferal biozones are recognized from the above-mentioned localities, these are in ascending order, the Favusella washitensis biozone (a local established biozone), Rotalipora cushmani biozone; Helvetoglobotruncana helvetica biozone; Concavutruncana concavata biozone; Concavutruncana asymetrica biozone; Globotruncanita elevata biozone; and Globotruncana aegyptiaca/Gansserina gansseri biozones. In addition to four Paleocene foraminiferal biozones in ascending order: the Parvularugoglobigerina eugubina biozone, Morozovella angulata biozone, Morozovella pseudobulloides biozone and Planorotalites pseudomenardii biozone. However, these biozones are difficult to recognize in most occasions due to the absence of the diagnostic species which is attributed to the unsuitable paleoenvironment and/or to the destructive diagenetic process. Accordingly, a biostratigraphical correlation has been also constructed in order to verify the possible unconformity surfaces as well as the nature of Cretaceous/Early Tertiary boundary.
Keywords: Foraminifera; biozones; Cyrenaica; Favusella; Concavutruncana
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