Early Maastrichtian-Early Eocene Biostratigraphy of El Hasana Area, Central Sinai, Egypt

Abstract

Ten calcareous nannofossils and ten planktic foraminiferal biozones were recognized from two sections measured in El Hasana area, in Central Sinai, Egypt. In the West El Hasana section, an early Maastrichtian/early Paleocene (K/Pg) unconformity was recorded due to the absence of the planktic foraminiferal Gansserina gansseri, Abathomphalus mayaroensis, and Globigerina eugubina Zones and the calcareous nannoplankton Micula prinsii and Markalius inversus Zones. The early Paleocene is represented by two biozones, Morozovella pseudobulloides (P1b) and Morozovella trinidadensis (P1c) that correlate with the Cruciplacolithus tenuis Zone (NP2), Chiasmolithus danicus Zone (NP3), and Ellipsolithus macellus Zone (NP4). In both sections, during the middle Paleocene three biozones were recorded: Morozovella uncinata (P2), the lower part of P3 Morozovella angulata, and Planorotalites pusilla pusilla (upper part of P3). The first and second biozones are equated with the upper two thirds of Ellipsolithus macellus (NP4), while the third one is correlated with Fasciculithus tympaniformis Zone (NP5). In the West El Hasana section, the Planorotalites pseudomenardii Zone (P4) ends the measured section. A small hiatus was observed across the late Paleocene/early Eocene (P/E) boundary in the East El Hasana section. This hiatus is due to the absence of the Planorotalites pseudomenardii Zone (P4), Morozovella velascoensis Zone (P5), M. edgari Zone (lower part of P6) and Heliolithus kleinpellii Zone (NP6), Discoaster molheri Zone (NP7), Heliolithus riedelli/Discoaster nobilis Zone (NP8), and Discoaster spp. (e.g., D. araneus) Subzone NP9a. The P/E boundary in East El Hasana section is delineated with the appearance of Rhomboaster spp. (e.g., Rhomboaster bitrifida) NP9b Subzone that coincides with the appearance of the planktic foraminiferal Morozovella subbotinae Zone (upper part of P6).