Stratigraphy and Palaeontology
Peiman Rajabi
Abstract
The Asmari carbonate formation in Lorestan is seen in the form of a medium to the thick limestone-rich layer of benthic foraminifera and often as a rock formation. In this study, the stratigraphic sequence of Asmari carbonate formation in the Chenareh Anticline section located in the south of Lorestan ...
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The Asmari carbonate formation in Lorestan is seen in the form of a medium to the thick limestone-rich layer of benthic foraminifera and often as a rock formation. In this study, the stratigraphic sequence of Asmari carbonate formation in the Chenareh Anticline section located in the south of Lorestan basin and Amiran Anticline section located in the middle part of Lorestan basin were studied in terms of lithology and micro biostratigraphy. The thickness of the Chenareh Section was 180 meters and the Section of Amiran Anticline was 158 meters. In total, more than 290 thin sections of both were prepared and examined in the laboratory. The results of fossil studies based on the expansion of foraminifera finally lead to the introduction and presentation of 1 Assemblage biozone in the Amiran anticline section and 3 Assemblage biozones related to the Chenareh anticline stratigraphic section. Accordingly, the age of the Asmari Formation is in the Chenareh section is Oligo-Miocene (Chattian-Bordigalian) and in the Amiran section is Miocene (Bordigalin). According to the lithostratigraphic studies, the border of the Asmari Formation in both sections of Chenareh and Amiran with Shabazan Formation is progressive-continuous and discontinuous, and in both sections of the upper boundary with Gachsaran Formation can be seen in the same way as evaporative sediments.
