List of Articles Tirgan Formation

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  1 - Biostratigraphy of the Tirgan Formation in Robat-Eshgh (south-west of Bojnurd) and Ghezelghan (North of Bojnurd) stratigraphic sections, and comparing them with each other.
  nassim Riahi عباس  صادقی Mohammad Hossein Adabi حسین  کامیابی شادان
  In order to study biostratigraphy of the Tirgan Formation in western Kopet Dagh, two surface sections including Navia – Robat Eshgh and Ghezelghan, were selected and 230 samples were collected. The Tirgan Formation was measured with a total thickness of 237 and 192 mete More

  In order to study biostratigraphy of the Tirgan Formation in western Kopet Dagh, two surface sections including Navia – Robat Eshgh and Ghezelghan, were selected and 230 samples were collected. The Tirgan Formation was measured with a total thickness of 237 and 192 meters in Navia and Ghezelghan sections respectively and was represented by thick and sometimes medium bedded, grey and weathered cream colored limestones in two localities. In Navia section, the Tirgan Formation conformably overlies the Zard – Shurijeh Formation with sharp lithological changes. However, as a result of being located in the core of an anticline, this boundary is not determined in Ghezelghan section. The Tirgan Formation disconformably underlies the Abderaz Formation in Navia section while conformably underlies the Sarcheshme Formation at Ghezelghan section. As a result of biostratigraphical investigations, 58 species belonging to 68 genera of foraminifera were identified in the Tirgan Formation. Based on benthic foraminifera two biozones were determined as follows: 1. Palorbitolina lenticularis Taxon Range Zone 2. Novalesia producta – Orbitolina spp. assemblage zone According to the determined biozones and fossils associations, the age of the Tirgan Formation is Barremian – Early Aptian in both sections. The comparison of the Tirgan Formation, in two-mentioned sections, shows some differences. In terms of biostratigraphy, there is not any significant distinctions, except for thickness difference in biozones. Manuscript profile
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  2 - Biocorrelation, Biostratigraphy and determination basal of the Aptian stage at Tirgan Formation , west of Kopeh-Dagh sedimentary basin, NE Iran
  Atefeh Chenarani Meysam Shafiee Ardestani Mohammad Vahidinia
  10.52547/ispg.33928.11.21.78
  Tirgan Formation (Lower Cretaceous) in the Kopeh-Dagh sedimentary basin consists mainly of Oolitic, Orbitolina, dolomitic limestones that conformably overlies the Shurijeh and Sarcheshmeh formations, respectively. Upper contact of Tirgan Formation at Jozak section with More

  Tirgan Formation (Lower Cretaceous) in the Kopeh-Dagh sedimentary basin consists mainly of Oolitic, Orbitolina, dolomitic limestones that conformably overlies the Shurijeh and Sarcheshmeh formations, respectively. Upper contact of Tirgan Formation at Jozak section with Abderaz Formation is faulty and were placed under white chalky limestone of the Abderaz Formation. Two stratigraphic sections at Estarkhi and Jozak were measured and sampled. Biostratigraphicic studies lead to two benthic foraminifera and calcareous green algae fossil assemblages have been identified. Twenty one genera and 24 species of benthic foraminifera and 16 genera and 26 species of calcareous green alge at Estarkhi section, 21 genera and 26 species of benthic foraminifera and 10 genera and 10 species of calcareous green alge at Jozak section in west of Kopeh-Dagh sedimentary basin have been identified. This study has been suggested the Barremian- Early Aptian( Bedulian) stage for the Tirgan Formation at these localities that is corresponded with age of central and east basin. Also based on paleobio-events study were determined base of the Aptian stage in east of the kopeh-Dagh sedimentary basin base of FA(First Appearance) Dictyoconus pachymarginalis and LA(Last Appearance) Montseciella arabica and in center and west of the basin base of the FAs Palorbitolina lenticularis, Salpingoporella muehlbergii. Manuscript profile