Paleoecology of the Maastrichtian and Danian sediment at North of Central Alborz, Iran, based on Planktonic foraminifera

Abstract

In order to study the fossil contents of the Ziarat-kola section for biostratigraphical purposes the 212 meters was sampled at Central Alborz. The sequence is mainly made up of monotonous grey-green to light grey marl. Based on Planktonic foraminifera age of Maastrichtian-Danian is determined to the section.Four zone were determined by the benthic foraminifera morphogroup for showing oxygen and productivy change. The approximate Low oxygen and high food supply has been indicates zone of one that increase infauna to epifauna morphotype percent is low(nearness 60% infouna , 40% epifauna). In zone two, with due attention to equal percent of Epifauna ratio to infauna , intermediate oxygen and food supply is anticipated .The decrasing epifauna foraminifera and increasing infauna demonstrates low oxygen and high food supply condition at zone of three. In zone four, increasing epifauna (approximate 90 percent) that are indicated high oxygen condition and low food supply. Analysis of planktonic foraminifera assemblage at this section with Cretaceous biostratigraphical provinces is indicating a close similarity with Tethyan provinces.