TITLE:
Biostratigraphy and Paleoecological Study of Pabdeh Formation in Interior Fars, Zagros Basin, Iran
AUTHORS:
Manooseh P. Khavari Khorassani, Fatemeh Hadavi, Ebrahim Ghasemi-Nejad, Reza Mousavi-Harami
KEYWORDS:
Biostratigraphy, Pabdeh Formation, Zagros, Ecozone, Nannofossil
JOURNAL NAME:
Open Journal of Geology,
Vol.4 No.11,
November
27,
2014
ABSTRACT: The Zagros basin, which
trends NW-SE, is covered by a sea during the Paleogene, resulting in deposition
of the Pabdeh Formation in the deeper parts of the basin. The thickness of the
Pabdeh Formation in Tang-e-Abolhayat is about 221 m and it consists of purple
shale at the base, gray shale, marl and marly limestone with a few horizons of
nodular limestone toward the top. Seventy-two samples were collected and
processed for nannofossil studies. Based on the identified nannofossil zones the age of the formation in
Tang-e-Abolhayat is Late Paleocene-Late Oligocene (NP9-NP24). Changes in the abundance of different
genera over the studied interval have resulted in identification of three ecozones:
Ecozone 1 is characterized by oligotrophic conditions with an abundance of warm
water taxa; Ecozone 2 marks when conditions became more eutrophic and the
abundance of temperate taxa increased; Ecozone 3 represents a return to
oligotrophic conditions with an increase in warm water taxa.