Calcareous Nannofossil Biostratigraphy of Maastrichtian-Paleocene Oil Shales from Jordan

Local biostratigraphic scheme based on calcareous nannofossil assemblages has been suggested in this work for upper Cretaceous and Paleocene oil shale successions. A total of 148 smear slides are studied from three oil shale boreholes throughout Jordan for their content of calcareous nannofossils. Six calcareous nannofossil biozones for Maastrichtian and nine zones for Paleocene are recognized from well OS-28. Cretaceous/Paleocene (K/P) and Paleocene/Eocene boundaries are detected either by calcareous nannofossil extinction or gamma ray. The K/P boundary appears to be missed. Although the short hiatus at K/P boundary is present, a distinctive gamma ray excursion remarked this boundary. Calcareous nannofossil assemblages were recovered gradually in the Danian, Complete biostratigraphic zones from Early Paleocene to Late Paleocene are recognized without any sedimentation break or hiatus in the central Jordan. Whereas uplift is proposed during Early to Late Paleocene to mark the hiatus in the northern and southern Jordan. Maastrichtian and Paleocene oil shales were deposited in the deep pelagic ramp, and the absence of allochthonous calcareous nannofossils provides strong evidence for that the sub-basins have not been exposed to winnowing and erosion process.