Z. latifi; F. Foroughi; M. Motamedalshariati; S. N. Raeisossadat
Abstract
Calcareous nannofossils of Nimbolook section in north west of Qayen, east of Iran have been investigated. The section is 164 m thick and consists of limestone, marlstone and shale. Seventy six nannofossil species belong to thirty genera from fifteen families were identified. Based on the identified calcareous ...
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Calcareous nannofossils of Nimbolook section in north west of Qayen, east of Iran have been investigated. The section is 164 m thick and consists of limestone, marlstone and shale. Seventy six nannofossil species belong to thirty genera from fifteen families were identified. Based on the identified calcareous nannofossils, a part of subzone CC7b and biozone CC8 and a part of biozone CC9 of Sissingh biozonation (1977) and a part of subzone NC7 and biozones NC8, NC9 and a part of biozone NC10 of Roth biozonation (1978) have been suggested for the Nimbolook section. Therefore, an age of late Aptian–Albian and early Cenomanian? is assigned to the deposits of this section.
H Mosaddegh; M Hadi; M Parandavar
Abstract
The Eocene marine deposits in the Chenarbu section in Torbat-e-Jam region (eastern part of Central Iran Zone) have been biostratigraphically studied based on large benthic foraminifera coincide with Shallow Benthic Zones (SBZ) and Calcareous Nannofossils, according to standard worldwide zones (NP). This ...
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The Eocene marine deposits in the Chenarbu section in Torbat-e-Jam region (eastern part of Central Iran Zone) have been biostratigraphically studied based on large benthic foraminifera coincide with Shallow Benthic Zones (SBZ) and Calcareous Nannofossils, according to standard worldwide zones (NP). This investigation has been conducted on carbonate sediments with a focus on large benthic foraminifera assemblage such as Eorupertia magna (La Calvaz), Fabiania cassis (Oppenheim), Eoannulariaeoconica (Cole ve Bermudez), Gypsina sp., Textularia sp., Nummulites perforatus (De Montfort) Nummulites sp., Discocyclina sp., Rotalia sp., Acervulina sp., and calcareous nannofossils such as Cribrocentrum reticulatum, Sphenolithus obtusus, Sphenolithus spiniger, Sphenolithus editus, Helicosphaera compacta, Coccolithus pelagicus, Coccolithus eopelagicus, Reticulofenestra sp., Discoaster sp., Discoaster siapanensis, Discoaster barbadiensis. Therefore, based on the determined index species, the SBZ15?- 17 biozones of large benthic foraminifera and the NP16 biozone of calcareous nannofossils in the studied section have been detected which both assign the Late Lutetian- Early Bartonian (Middle Eocene) age for the section.Also, the Lutetian- Bartonian boundary according to index calcareous nannofossil species was separated carefully, and the first appearance of the foraminifera species of N. perforatus (de Montfort) in the middle part of the deposited sequence was recorded during geological time of the Bartonian stage. Therefore, this fact points that in Iran alike western parts of the Tethys basin, the first appearance of N. perforatus (de Montfort) occurred in Early Barthonian (SBZ17). Systematic of Nummulites perforatus (de Montfort) was described based on typological and biometrical characterization.
F Jalili; F Hadavi; B Rahimi; A.R Khazaei
Abstract
In this research, biostratigraphy of a stratigraphic section in the east Afzalabad section in Lut Block (part of flyschoid basin in East Iran) were investigated based on calcareous nannofossils. Nineteen genera and 52 species of calcareous nannofossils were identified based on which the studied ...
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In this research, biostratigraphy of a stratigraphic section in the east Afzalabad section in Lut Block (part of flyschoid basin in East Iran) were investigated based on calcareous nannofossils. Nineteen genera and 52 species of calcareous nannofossils were identified based on which the studied sequence confirm with NN8- NN10 biozones of Martini (1971) indicating a middle Miocene to late Miocene age.
A Ahifar; A Kani; H Amiri Bakhtiar
Abstract
Pabdeh Formation has been investigated in three sections viz. the Type Section, Tang-e Hatti and the northern limb of Gurpi Anticline within the ZagrosSedimentaryBasin with emphasis on calcareous nannofossils. Study of microscope slides prepared from the 1508 collected samples resulted in determination ...
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Pabdeh Formation has been investigated in three sections viz. the Type Section, Tang-e Hatti and the northern limb of Gurpi Anticline within the ZagrosSedimentaryBasin with emphasis on calcareous nannofossils. Study of microscope slides prepared from the 1508 collected samples resulted in determination of 256 species belonging to 59 genera from 22 families of nannofossils and biostratigraphic classification was carried out based on their stratigraphic distribution. According to Martini (1971) zonal scheme, presence of NP4-NP23 nannofossil zones at the Type Section, and NP5-NP23 nannofossil zones at both Tang-e Hatti and northern limb sections have been ascertained thus indicating Early Paleocene to Early Oligocene age for the Pabdeh Formation at these three localities. Calcareous nannofossil assemblages reveal sedimentation of Pabdeh Formation occurred in an oligotrophic, warm water environment during Paleocene-Eocene which was later on replaced by a relatively cooler water condition in Oligocene times.
F Foroughi; A Lotfali Kani; S Gardin; M Vahidinia
Abstract
The Kopet-Dagh basin is located in the northeast of Iran, in the triangle border of Iran, Turkmenistan and Afghanistan and consists of the marine Jurassic to Neogene strata. The Abtalkh Formation is one of the thickest lithostratigraphic upper Cretaceous units in the eastern Kopet-Dagh basin and is composed ...
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The Kopet-Dagh basin is located in the northeast of Iran, in the triangle border of Iran, Turkmenistan and Afghanistan and consists of the marine Jurassic to Neogene strata. The Abtalkh Formation is one of the thickest lithostratigraphic upper Cretaceous units in the eastern Kopet-Dagh basin and is composed of light gray, green to bluish marl and silty marl. The Abtalkh Formation conformably overlies the Abderaz Formation, which contains marls and chalky limestones and is conformably overlain by the Nayzar Formation, which consists of sandstone, silty marl and limestone. The Abtalkh Formation contains very aboundant, rich and good to moderately preserved calcareous nannofossil assemblages of Tethyan realm. The total 220 samples in the jalilabad and 467 samples in the AbtalkhVillage stratigraphic sections, representing the oldest and youngest strata of upper Abderaz, Abtalkh and base of Nayzar successions, were collected. The thickness of Abtalkh Formation in the Jalilabad stratigraphic section is 1325.8m and for the AbtalkhVillage stratigraphic section is 1765m. One hundred sixteen nannoplanktonic species belonging to forty three genera and fifteen families were identified. The biostratigraphic study allowed the recognition of the calcareous nannofossil biozones of Sissingh (1977) emended by Perch-Nielsen (1985) and Burnett (1998). From bottom to top, part of CC19, CC20, CC21, CC22, part of CC23a biozones and UC14dTP, UC15bTP, UC15cTP, UC15dTP subzones and UC16 biozone were identified in the Jalilabad section. The Abtalkh Village section in the middle of eastern Kopet-Dagh basin is started with CC20 (UC15bTP) biozone and continued to CC23a (UC16) biozone. Nearly more than 30 calcareous nannofossil species were reported for the first time in Iran. The results of this study indicated that the age of Abtalkh Formation spans from early to uppermost Late Campanian for these two sections in the Kopet-Dagh basin.
