Abstract

This study focuses on late Paleocene–middle Eocene planktonic and small benthic foraminiferal assemblages from the Khangiran Formation in the Kopet-Dagh Basin (NE Iran). The patterns of regional distribution of foraminiferal fauna were observed in this study, although many of the global foraminiferal index species are absent in the studied southernmost Peri-Tethys neritic section. Accordingly, this work proposes to update a regional biostratigraphic scheme and correlation with adjacent basins based on the first and last appearance of diagnostic species. Biozones correlative with Acarinina acarinata Zone, Morozovella subbotinae Zone, Morozovella aragonensis Zone, Acarinina bullbrooki Zone, and Acarinina rotundimarginata Zone of interregional zonal scheme based on planktonic foraminifera and biozones correlative with Annectina paleocenica Zone, Pseudogaudryina externa Zone, and Pseudogaudryina pseudonavarrana Zone based on small benthic foraminifera were recognized in the type section of the Khangiran Formation indicating Thanetian-middle Lutetian age. Toward the upper part of the studied section in the last phase of marine sedimentation regional oyster beds (Sokolowia spp.) point out late Lutetian-early Priabonian age. Possibly Arctic-Tethys communication systems through the early Paleogene epicontinental seas were responsible for the faunal assemblage similarities and suggest that the Kopet-Dagh Basin of Iran was connected to northern basins of Former Soviet Union and other Central Asian basins during the Paleogene.

中文翻译：

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来自Kangiran组类型剖面的晚古新世-中始新世浮游和小型底栖有孔虫动物群，Kopet-Dagh盆地（伊朗东北部），最南端的Peri-Tethys

摘要

这项研究的重点是来自 Kopet-Dagh 盆地（伊朗东北部）的 Khangiran 组的晚古新世 - 中始新世浮游生物和小型底栖有孔虫组合。在这项研究中观察到有孔虫动物区系的区域分布模式，尽管在研究的最南端的 Peri-Tethys 浅海剖面中没有许多全球有孔虫指数物种。因此，这项工作建议根据诊断物种的首次和最后一次出现更新区域生物地层方案和与相邻盆地的相关性。与 Acarinina acarinata 区、Morozovella subbotinae 区、Morozovella aragonensis 区、Acarinina bullbrooki 区和 Acarinina rotundimarginata 相关的生物区基于浮游有孔虫的区域间地带计划区和与 Annectina 古新世区相关的生物区，在Khangiran组的类型剖面中识别出Pseudogaudryina externa Zone和基于小型底栖有孔虫的Pseudogaudryina pseudonavarrana Zone，表明Thanetian-middle Lutetian时代。朝海洋沉积末期区域牡蛎床研究剖面的上部（Sokolowia spp.) 指出了卢特阶晚期 -普里亚博阶早期。可能是北极-特提斯通讯系统通过早期古近纪陆上海造成了动物群落的相似性，并表明伊朗的 Kopet-Dagh 盆地在古近纪期间与前苏联北部盆地和其他中亚盆地相连。