THE PALEOCENE OF CENTRAL EAST SINAI, EGYPT - SEQUENCE STRATIGRAPHY INMONOTONOUS HEMIPELAGITES

Tracking sequences in hemipelagic facies is complicated because of the rather monotonous appearance of the hemipelagic deposits, lack of sub aerial exposure, and absence of typical sequence stratigraphic geometr ies. This study addresses how the sequence stratigraphic model can be applied in hemipelagic environments. Eight latest Maastrichtian to ear ly Eocene hemipelagic sections from Central East Sinai have been recor ded and biostratigraphically and paleobathymetrically studied by means of planktic and benthic foraminifera, calicareous nannofossils and se dimentological observations. Sea-level changes were reconstructed usin g the foraminiferal planktic/benthic ratio, hiatuses, hard calcareous marl beds, and benthic foraminifera. Correlation of the observed paleo bathymetric cycles yielded a sea-level history for the region consiste nt with the existing literature. Candidate systems tracts boundaries w ere interpreted using a simple model that provides an approximate rela tionship between relative sea level and systems tracts. Sequence strat igraphic history was compared with regional sea-level curves from cent ral/southern Egypt, Tunisia and Texas, as well as with European (Harde nbol and others, in press) and 'global' (Haq and others, 1987) sequenc e charts. Correlation is excellent for the early and middle Paleocene (WT boundary to mid Globanomalina pseudomenardii Zone). Deposition in Central Sinai during this time may, therefore, have been predominantly controlled by eustatic sea level rather than local tectonics. Interpr etation of sea-level development in the late Thanetian is more ambiguo us. The study demonstrates the applicability of the sequence stratigra phic concept in suitable hemipelagic environments. The Paleocene hemip elagites of Sinai represent a paleobathymetric interval suitable for s ea-level changes to be recorded in the foraminiferal faunal compositio n in terms of the planktic/benthic ratio.