Resumen de Biostratigraphy of the Late Paleogene-Early Neogene succession, north-central border of Persian Gulf, Iran

Ali Seyrafian, Alireza Mojikhalifeh

• The Late Paleogene-Early Neogene succession studied at the Khurmug area, on the northern flank of the Persian Gulf, includes upper part of the Jahrum, lower and middle parts of the Asmari and the most lowest part of the Gachsaran Formations.

  The upper part of the Jahrum Formation is characterized by limestones from theDictyoconus-Coskinolina-Orbitolites andGloborotalia renzi-Globigerina assemblage zones of the Middle Eocene. The lower part of the Asmari Formation is gypsiferous marly, dolomitic limestones, and limestones from theNummulites-Operculina assemblage zone of the Middle Oligocene (Rupelian) age. The middle part of the Asmari Formation is gypsiferous dolomitic limestone and limestone from theArchaias-Peneroplis assemblage zone of Early Miocene (Aquitanian) age. The lower part of the Gachsaran Formation is characterized by thick-bedded anhydrite and thin beds of dolomitic marls, with miliolids, reflects deposition during to Late Aquitanian through Burdigalian.

  Within the above succession, two conformable non-conformities correlatable to Priaborian-Lattorfian and Chattian times is recognized. Also, unlike most of the Zagros Basin, marine carbonate deposition (correlatable to the upper parts of the Asmari Formation) is replaced by the evaporitic facies of the Gachsaran Formation during that accumulated the Burdigalian time.