BIOSTRATIGRAPHY OF SOME SUBSURFACE MIOCENE ROCKS, NILE DELTA, MEDITERRANEAN­ EGYPT

Abstract

The present work deals with the biostratigraphy and paleobathymetry of the Miocene subsurface section of the offshore northeastern part of the Nile Delta of Egypt. Three subsurface Miocene sections have been analyzed from the wells; Horus-1, Akhen-1 and Osiris-1 east. 115 species and subspecies, beloging to 42 foraminiferal genera, were identified and discussed. Most of these species were photographed and illustrated. Six planktonic zones and two subzones were established, these are, from top to base, as follows: 1.Sphaeroidinellopsis Spp Zone (Early Pliocene) • 2.Non-distinctive Zone (Late Miocene) 3.Globigerinoides obliquus extremusl Globorotalia acostaensis Zone (Late Miocene) 4.Globorotalia menardii s.l. Zone (Middle Miocene) 5.Globorotalia siakensis Zone (Middle Miocene) •Globorotalia siakensis/Globigerinoides obliquus obliquus Subzone •Globigerinoides subquadrata/ Globoquadrina altispira altispira Subzone 6.0rbulina suturalis/Globorotalia peripheroronda. Zone (Middle Miocene) The paleobathymetric studies on the three wells, leads to conclude that the Middle and Late Miocene periods have witnessed two major transgressive and regressive cycles, respectively.