Biozonation and Paleobathymetry on Foraminifera Upper Cretaceous Deposites of Central Iran Basins (Isfahan, Baharestan Section)

Bita Ghasem Shirazi, Lida Bakhshandeh, Abdollah Yazdi

Department of Geology, Kahnooj Branch, Islamic Azad University, Kerman, Iran.
Department of Geology, Science and Research Branch, Islamic Azad University, Tehran, Iran.

DOI: 10.4236/ojg.2014.48026                

Abstract

In this study Late Cretaceous stratum in central Iran, Baharestan section in Isfahan area, was evaluated by biozonation and paleobathymetry. These sediments have 89 meters thick, and strata have been formed of marl and marl limestone. In order to indicate the ancient depth of Upper Cretaceous at this time, planktonic and benthic foraminifera were studied. The percentage of the total planktonic foraminifera to the whole sample of foraminifera after the removal of indwell benthic foraminifera (%P*) using the formula D = e(3.58718 + (0.03534 × %P*)) was identified and depth of 200 - 450 meters was achieved for them. In the present investigation, 30 planktonic species of 11 genus have been identified. The Upper Cretaceous deposit was divided to 6 biozones on the basis of planktonic foraminifera which are cosmopolitan and consist of: Biozone 1—Marginotruncana sigali-Dicarinella primitiva partial range zone; Biozone 2—Dicarinella concavata interval zone; Biozone 3—Dicarinella asymetrica total range zone; Biozone 4—Globotruncanita elevata partial range zone; Biozone 5—Globotruncana ventricosa interval zone; Biozone 6—Radotruncana calcarata interval zone. Based on planktonic foraminifera, the Upper Cretaceous sediments in the study area are of the Turonian-Late Campanian ages.

Keywords

Biozonation, Foraminifera, Central Iran, Paleobathymetry, Turonian, Late Campanian

Conflicts of Interest

The authors declare no conflicts of interest.

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