Biostratigraphy of the Katkoyeh Formation in the Asyab-Valley section, northwest of Kerman (southeast of Zarand) based on conodont fauna
Subject Areas : زمین شناسی نفتfirozeh balaghati 1 , Ali Bahrami 2 * , Hosyen Vaziri moghadam 3 , Hamed Ameri 4 , Yazdi Yazdi 5 , Gustavo Gabriel Voldman 6
1 - Department of Geology, University of Isfahan
2 -
3 - Department of Geology, University of Isfahan
4 - , Department of Ecology, Institute of Science, High Technology and Environmental Science,
5 - professor
6 - PhD Stratigraphy and Paleontology, Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET, Universidad Nacional de Córdoba, X5016GCB Córdoba, Argentina
Keywords: Ordovician, Katkoyeh Formation, northwest Kerman basin, Asyab-valley, Katkoyeh, Zarand,
Abstract :
Ordovician marine sedimentary sequences occur in several structural blocks widely in Iran, along the northern margin of Gondwana. In north Kerman province, the Ordovician deposits are known as the Katkoyeh Formation, which includes 70 to 300 meters of siliciclastic rocks with rare and thick pyroclastic carbonate layers in its upper part. In order to better percise biostratigraphy of the Katkoyeh Formation in Kerman region, systematic sampling for conodonts was carried out in Asyab-valley section, located about 12 km southeast of Zarand city, the thickness of Ordovician deposits in the studied section is 154/4 meters. The Ordovician deposits of Katkoyeh Formation in the studied section includes silty shales, diabase, pilolava, basaltic tuffs, red sandstone, marl, limestone and sandy limestone. After sampling and recovery of conodonts, a total of nearly 680 conodont elements were obtained from the studied samples, a total of 14 genera and 21 species of conodonts were discriminated. Based on the occurrence of biostratigraphically important species, three conodont ranges have been recorded. These three biozones are:
1) Rossodus manitouensis/Paltodus deltifer Concurrent Range Zone (the lowest part of Late Tremadocine; Early Ordovician)
2) Juanognathus variabilis Range Zone (Fluvian; Early Ordovician)
3) Icriodella superba Range Zone (Katian - ? Hirnantian; Late Ordovician)
Considering the CAI (5) of recovered conodont elements, the region has a high thermal history and the presence of hydrocarbon materials in the deposits of this area is ruled out.