Stratigraphy and Palaeontology
Kamyar Younesi; Anoshiravan Lotfali Kani; Hormoz Ghalavand
Abstract
A conformable passage between Sarvak and Surgah Formations in Lurestan sedimentary basin reveals the potential of studying the Turonian–Coniacian boundary within Surgah Formation. Two sections of the Surgah Formation at Posht-e-Jangal and Pasan anticlines situated on the southeast of the Lurestan ...
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A conformable passage between Sarvak and Surgah Formations in Lurestan sedimentary basin reveals the potential of studying the Turonian–Coniacian boundary within Surgah Formation. Two sections of the Surgah Formation at Posht-e-Jangal and Pasan anticlines situated on the southeast of the Lurestan sedimentary basin have been studied on the basis calcareous nannofossils, and based on the observed distribution of nannoflora, the presence of CC12 to CC16 nannofossil biozones is documented which points to the latest Turonian to Coniacian age for the base of this Formation, while the top boundary is estimated approximately at earliest Santonian. Due to the absence of Micula staurophora, however, separation of CC13 and CC14 biozones is not possible and therefore, the Turonian–Coniacian boundary is placed somewhere within the said undivided interval. The FO of Calculites obscurus as the marker event for the top of CC16 biozone is not identified but on the basis of suspected LO of Lithastrinus septenarius as the marker event of the top of UC11 and onset of UC12, the record of early Santonian beds seems probable.
Stratigraphy and Palaeontology
Saeedeh senemari; Narges Monjezi
Abstract
Pabdeh Formation to Asmari Formation transition deposits were studied in the stratigraphic section of Khaviz located in the northeast of Behbehan. In the present research, the deposits of the upper part of Pabdeh Formation consisting shale and interbedded of argillaceous gray limestone with a thickness ...
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Pabdeh Formation to Asmari Formation transition deposits were studied in the stratigraphic section of Khaviz located in the northeast of Behbehan. In the present research, the deposits of the upper part of Pabdeh Formation consisting shale and interbedded of argillaceous gray limestone with a thickness of about 66 m were studied, which are followed by deposits of the lower part of Asmari Formation with a thickness of about 21 m, including cream-colored clay limestone. As a result of this study, 33 species belonging to 15 genera of calcareous nannofossils were identified. Based on the recorded bio-events and associated fossil assemblages, the bio-zones of Sphenolithus pseudoradians Zone, Ericsonia subdisticha Zone, Helicosphaera eticulate Zone, Sphenolithus predistentus Zone, Sphenolithus distentus Zone were determined. The studied zones are consistent with CNE20- CNO4/ CNO5 from Agnini et al. (2014) zonation. Based on the introduced bio-zones, the age of the upper part of Pabdeh Formation in the studied section of the Priabonin-early Rupelian and the age of the lower part of the Asmari Formation Rupelian-Chattian are suggested. In this study, the boundary between Pabdeh and Asmari formations is continuous, which indicates sedimentation with decreasing depth in the boundary of these two formations.
Stratigraphy and Palaeontology
nahid khodashenas; Fatemeh Hadavi; Marziyeh Notghi Moghaddam; Ahmadreza Khazaei
Abstract
In the present study, Baghamshah Formation in Baghdadeh section located in the eastern margin of Lut Block to biostratigraphic studies based on calcareous nannofossils was sampled. Thickness of Baghamshah Formation in this section is 253m and mainly contains of shale and marl. According to the paleontological ...
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In the present study, Baghamshah Formation in Baghdadeh section located in the eastern margin of Lut Block to biostratigraphic studies based on calcareous nannofossils was sampled. Thickness of Baghamshah Formation in this section is 253m and mainly contains of shale and marl. According to the paleontological studies, 43 nannofossil species belong to 20 genera with well to moderate preservation in Baghdadeh section were identified and photographed. Based on the index calcareous nannofossils and assemblages species, CC1-CC5 biozones of Sissingh (1977) were determined. According to determined biozones, age of the Baghamshah Formation in Baghdadeh section Early Berriasian to Early Barremian was suggested.
Stratigraphy and Palaeontology
Azam Mahanipour; Maryam Eftekhari; Soheila Soheili
Abstract
In order to study the early Aptian Oceanic Anoxic Event 1a (OAE 1a), calcareous nannofossils are investigated at the late Barremian ‒ early Aptian sediments of the Garau Formation at south west of the Kabir-Kuh anticline, Qaleh-Darreh section. Ninety species of calcareous nannofossils from 43 genus ...
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In order to study the early Aptian Oceanic Anoxic Event 1a (OAE 1a), calcareous nannofossils are investigated at the late Barremian ‒ early Aptian sediments of the Garau Formation at south west of the Kabir-Kuh anticline, Qaleh-Darreh section. Ninety species of calcareous nannofossils from 43 genus and 15 families are identified along with marker species like Hayesites irregularis and Eprolithus floralis. Based on index calcareous nannofossil taxa, the studied interval is located between the uppermost part of the CC6/NC5 and the early part of CC7/NC7A. The first occurrence of H. irregularis, the marker of the Barremian ‒ Aptian boundary, used as an index species between CC6/NC5E and CC7/NC6. Statistical analysis of the calcareous nannofossil assemblages at the studied interval indicate the presence of nannoconid decline at the Barremian ‒ Aptian boundary and early Aptian and nannoconid crisis at CC7a/NC6B biozone. Nannoconid crisis is one of the main markers of the early Aptian OAE 1a that is recorded from different parts of the world at the Tethys and Boreal realms, Atlantic and Pacific oceans at the early Aptian (NC6 biozone). At the current study the early Aptian OAE 1a is recorded from the Garau Formation based on calcareous nannofossil assemblages.
Stratigraphy and Palaeontology
A. Mahanipour; Reza Afrooz
Abstract
In the present study, calcareous nannofossil biostratigraphy was investigated at the Paleocene ‒ middle Eocene interval at northeast Kazerun (Shahneshin anticline). A thickness of 50 m from the upper part of Gurpi ‒ lower part of Pabdeh formations is investigated and mainly consists of marly limestone, ...
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In the present study, calcareous nannofossil biostratigraphy was investigated at the Paleocene ‒ middle Eocene interval at northeast Kazerun (Shahneshin anticline). A thickness of 50 m from the upper part of Gurpi ‒ lower part of Pabdeh formations is investigated and mainly consists of marly limestone, marly shale and marl. 180 species from 31 geneus of calcareous nannofossils are identified. According to the index calcareous nannofossils and based on Agnini et al. zonation, zone CNP3 to CNP11 and zone CNE1 to CNE8 are identified at the Paleocene and Eocene interval, respectively. These biozones corresponds with zone NP3 to NP9 (in Paleocene) and NP10 to NP14 (in Eocene), based on Martini zonation. Regarding calcareous nannofossil assemblages and biozones, the Paleocene ‒ Eocene boundary is located between CNP11/NP9 and CNE1/NP10 zones, where the top of Fasciculithus richardii group is recorded. The extinction of Fasciculithus is recorded at 23 m by the last occurrence of Fasciculithus tympaniformis, which is considered as an index for early Eocene. The appearance of some species, such as Rhomboaster spp., Tribrachiatus bramlettei and assymetrical species of Discoaster araneus is recorded at the Paleocene ‒ Eocene boundary similar to other parts of the world.
Stratigraphy and Palaeontology
s senemari
Abstract
In order to study biostratigraphy of the Pabdeh Formation in the Northeast Kazerun, Murdak section was selected. In this section, Pabdeh Formation is mainly consists of marl, shale and marly limestone. The study of calcareous nannofossils led to the recognition of 70 species and 28 genera. According ...
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In order to study biostratigraphy of the Pabdeh Formation in the Northeast Kazerun, Murdak section was selected. In this section, Pabdeh Formation is mainly consists of marl, shale and marly limestone. The study of calcareous nannofossils led to the recognition of 70 species and 28 genera. According to the first and last occurrence of index species and assemblages fossil, the following biozones based on global standard zonations are identified: Discoaster multiradiatus Zone (NP9/CP8a/CNP11), Tribrachiatus contortus Zone (NP10/ CP8b-CP9a/ CNE1- CNE2), Discoaster binodosus Zone (NP11/ CP9b/ CNE3), Tribrachiatus orthostylus Zone (NP12/ CP10/ CNE4), Discoaster lodoensis Zone (NP13/ CP11/ CNE5), Discoaster sunlodoensis Zone (NP14/ CP12/ CNE6- CNE8), Nannotetrina fulgens zone (NP15/ CP13/ CNE9-CNE11), Discoaster tanii nodifer Zone (NP16/ CP14a/ CNE12-CNE15), Discoaster saipanensis Zone (NP17/ CP14b/ CNE15- CNE16), Chiasmolithus oamaruensis Zone (NP18/CP15a/CNE17-CNE18), Isthmolithus recurvus Zone (NP19/CP15b/CNE18-CNE19), Sphenolithus pseudoradians Zone (NP20/ CP15b/ CNE20), Ericsonia Subdisticha zone (NP21/CP16a-b/CNE21-CNO1), Helicosphaera reticulate Zone (NP22/ CP16c/ CNO2), Sphenolithus predistintus Zone (NP23/ CP17- CP18 / CNO3- CNO4). As a result of this study and based on the obtained biozones, the age of Pabdeh Formation in Murdak section, is Late Paleocene (Thanetian) to Oligocene (Rupelian-Chatian).
Stratigraphy and Palaeontology
Katayoon Barmakizadeh; A. Mahanipour
Abstract
Abstract The lower part of the Garau Formation with a thickness of 212 m at the southwest of the Kabirkuh anticline is investigated with regard to the calcareous nannofossils. Lithology of the studied interval is mainly consists of marl, marly limestone, black shale and limestone. 67 species from 33 ...
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Abstract The lower part of the Garau Formation with a thickness of 212 m at the southwest of the Kabirkuh anticline is investigated with regard to the calcareous nannofossils. Lithology of the studied interval is mainly consists of marl, marly limestone, black shale and limestone. 67 species from 33 genus and 13 families are recognized. Nannofossil events that are recorded from base to top of the section are as follow: the first occurrence (FO) of Calcicalathina oblongata, the last occurrence (LO) of Rucinolithus wisei, the FO of Lithraphidites bollii, the LO of Cruciellipsis cuvillieri, the first occurrence of Assipetra terebrodentarius and the last occurrence of Lithraphidites bollii. According to these index calcareous nannofossils, the studied interval is ranging from the uppermost part of CC2/NK2 biozone to the middle part of CC5b/NC5C subzone Considering these zonations, the age of the studied interval is Valanginian ‒ Hauterivian. According to the calcareous nannofossil data, the Valanginian ‒ Hauterivian boundary can’t be determined. This boundary is located at the base of the Tethyan ammonite Acanthodiscus radiatus at the leading GSSP candidate in the La Charce section of southeastern France.
Stratigraphy and Palaeontology
Mohammad Hassan Shokri; Fatemeh Hadavi; Lida Khodadadi; M. Notghi Moghaddam; Hossein KAMYABI SHADAN
Abstract
Economically the Surgah Formation is the most significant in the Zagros sedimentary basin. In this study, the calcareous nannofossils have been investigated of the Surgah Formation from the Shah-nakhjir section. The thickness of the Surgah Formation is about 147 meters and composed of marly limestone ...
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Economically the Surgah Formation is the most significant in the Zagros sedimentary basin. In this study, the calcareous nannofossils have been investigated of the Surgah Formation from the Shah-nakhjir section. The thickness of the Surgah Formation is about 147 meters and composed of marly limestone deposits with diversity and well-preservation of calcareous nannofossil assemblages. In total, 41species belong to 22 genera were determinate and ultimately have compared with nannofossil standard zones. According to identified nannofossils, the age of the Middle Cenomanian- Middle Santonian corresponding to CC10- CC17 (Sissingh, 1977) includes Microrhabdulus decoratusZone (CC10), Quadrum gartneri Zone (CC11), Lucianorhabdus maleformis Zone (CC12), Marthasterites furcatus Zone (CC13), Micula decussataZone (CC14), Reinhardtites anthophorus Zone (CC15), Lucianorhabdus cayeuxii Zone (CC16), Calculites obscurus Zone (CC17) were suggested for the Surgah Formation in the studied section. Palaeoecological interpretations based on the identified species show warm climate and low depth conditions in low latitudes for deposits of the Surgah Formation in southwest of Ilam city (Shah-nakhjir section).
Stratigraphy and Palaeontology
Maryam Eftekhari; Azam Mahanipour; Mohammad Dastanpour
Abstract
Abstract Barremian sediments of the Garau Formation have been investigated at the southwest of the Kabir-kuh anticline (Qaleh-Darreh section) with regard to calcareous nannofossils. According to the presence of index calcareous nannofossils, NC5 biozone and NC5c, NC5d and NC5e subzones of Roth (1978) ...
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Abstract Barremian sediments of the Garau Formation have been investigated at the southwest of the Kabir-kuh anticline (Qaleh-Darreh section) with regard to calcareous nannofossils. According to the presence of index calcareous nannofossils, NC5 biozone and NC5c, NC5d and NC5e subzones of Roth (1978) and CC5-CC6 biozones of Sissingh (1977) have been identified. At the studied interval, warm water taxa like Cyclagelosphaera margerelii, Diazomatolithus lehmanii, Lithraphidites carniolensis, Micrantholithus spp., Nannoconus spp., Rhagodiscus asper and Watznaueria spp. have been recorded along with cool water taxa such as Biscutum constans, Helenea chiastia and Zeugrhabdotus embergeri. The abundance of warm water taxa is higher than cool water taxa and a reverse trend can be observed between them. Regarding cool and warm water taxa three warming phases and two cooling phases are identified which includes the warming event of early Early Barremian, cooling event of Early Barremian, warming event of Mid-Barremian, cooling event of late Barremian and warming event of Barremian-Aptian boundary. It must be mentioned that these data are in accord with other parts of the world in the Tethyan (e.g., Italy) and the Boreal realms (e.g., NW Germany and NE England). Keywords: Barremian, Biostratigraphy, Paleoecology, Garau Formation, Calcareous nannofossils.
N Mousavi; A L.Kani; A Mosavinia
Abstract
In this study the succession comprising Aitamir and Abderaz Formation boundary is investigated along Amir Abad section in eastern Koppeh-Dagh region. Based on Calcareous nannofossils and NC biozonation scheme, Late Albian to Late Turonian time of deposition is estimated for the measured succession. There ...
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In this study the succession comprising Aitamir and Abderaz Formation boundary is investigated along Amir Abad section in eastern Koppeh-Dagh region. Based on Calcareous nannofossils and NC biozonation scheme, Late Albian to Late Turonian time of deposition is estimated for the measured succession. There is some evidence such as paleoecological changes and increase in organic carbon burial, enabling recognition of the Cenomanian – Turonian Oceanic Anoxic Event (OAE2) in this section. Anoxic events often occur as a result of high productivity leading to increased burial of organic matter. Paleoecological trends recorded including decrease in abundance of Broinsonia spp. and Biscutum spp. and increase in Watznaueria spp. at the beginning of the late Cenomanian interval suggest prevalence of oligotrophic condition during this interval of time. In the late Late Cenomanian and Cenomanian-Turonian boundary intervals, the increase in relative abundance of surface water high fertility markers such as Biscutum spp. and the increase of fertility index i.e. (Biscutum+Zeugrhabdotus)/Watznaueria, point to amore eutrophic condition. The absence of Nannoconus spp., which are not seen in anoxic conditions, is another evidence of OAE2. The rising trend of total organic carbon content in the Late Cenomanian part of the sedimentary succession and the mentioned paleoecological evidences, suggest presence of Late Cenomanian Oceanic Anoxic Event in eastern Koppeh-Dagh. Although this global event is mostly reported from oceanic black shales, in some sections especially in the east of Tethys, it is sometimes recorded in shallow water sediments. Shale and marl succession in Koppeh-Dagh region can be considered as the continuation of their global trend in the eastern-most part of the Tethyan realm where the Late Cenomanian Oceanic Anoxic Event (OAE2) has occurred in a rather shallow environment of deposition.
Stratigraphy and Palaeontology
S. Senemari
Abstract
Calcareous Nannofossils of the Gurpi Formation have been investigated at Kalchenar section (Northwest of Izeh). In this section, the Gurpi Formation is mainly consists of marls, shaly marls and marly limestones. For introducing index species, calcareous nannofossil assemblages and biozones, 150 slides ...
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Calcareous Nannofossils of the Gurpi Formation have been investigated at Kalchenar section (Northwest of Izeh). In this section, the Gurpi Formation is mainly consists of marls, shaly marls and marly limestones. For introducing index species, calcareous nannofossil assemblages and biozones, 150 slides have been studied which led to the recognition of twelve biozones. As a result, 61 species, 35 genera of calcareous nannofossils were detected. According to the identified biozones, the age of the Gurpi Formation is Late Campanian to Late Paleocene (Late Selandian) and K/Pg boundary is continuous at the studied interval, that is corresponding to CC21- CC26of zonation scheme of Sissingh (1977) and NP1- NP6 of zonation of Martini (1971).
A Mahanipour; A Najafpour; M Dastanpour
Abstract
Calcareous nannofossils have been investigated at the lower part of the Gurpi Formation at the southwest of Gurpi anticline. According to the index calcareous nannofossils CC22/UC15eTP to CC24/UC18 bio-zones have been identified and the age of Late Campanian ‒ Early Maastrichtian is considered for ...
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Calcareous nannofossils have been investigated at the lower part of the Gurpi Formation at the southwest of Gurpi anticline. According to the index calcareous nannofossils CC22/UC15eTP to CC24/UC18 bio-zones have been identified and the age of Late Campanian ‒ Early Maastrichtian is considered for the studied interval. Statistical analysis of the assemblages indicate the presence of high and low nutrient taxa. The relative abundance of oligotrophic taxa (Watznaueria barnesae, Watznaueria fossacincta, Prediscosphaera spp., Eiffellithus spp., Lithraphidites carniolensis, Staurolithites spp., Micula staurophora, Cribrosphaerella ehrenbergii) is higher than eutrophic forms (Biscutum constans, Discorhabdus ignotus, Placozygus spiralis, Reinhardtites spp., Zeugrhabdotus spp., Tranolithus orionatus), and an increasing trend in the relative abundance of oligotrophic taxa along with a decreasing trend in the relative abundance of eutrophic forms can be observed towards the upper parts of the section (Campanian-Maastrichtian boundary and Early Maastrichtian).
A Gholami fard; A Kani; A Mahanipour
Abstract
This study investigates the Lower Cretaceous sedimentary succession comprising Sarcheshmeh Formation and Sanganeh Formation in the Ghaleh zoo Section from the standpoint of Calcareous Nannofossils. The results reveals presence of 60 species from 33 genera of 15 families. Based on the index nannofossil ...
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This study investigates the Lower Cretaceous sedimentary succession comprising Sarcheshmeh Formation and Sanganeh Formation in the Ghaleh zoo Section from the standpoint of Calcareous Nannofossils. The results reveals presence of 60 species from 33 genera of 15 families. Based on the index nannofossil taxa, the upper part of NC6, NC7A, NC7(B&C) and NC8(A&B) nannofossil zones (equivalent to the upper part of of CC7a, CC7b and CC8 zones), are present in this section. The calcareous nannofossils found in this section point to an Early Aptian to Late Aptian age of deposition for the rocks of Sarcheshmeh Formation and Late Aptian to Early Albian for the rocks of Sanganeh Formation.
Mohammad Parandavar; A Mahanipur; S. A Aghanabati; S. A. Hoseini
Abstract
In this study the upper part of Gurpi Formation and the lower part of Pabdeh Formation have been investigated with regard to the calcareous nannofossils. The thinkness of the studied section is about 127 meter and it consists of Marls, gray-green shales and purple shales. 50 genus and 101 species ...
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In this study the upper part of Gurpi Formation and the lower part of Pabdeh Formation have been investigated with regard to the calcareous nannofossils. The thinkness of the studied section is about 127 meter and it consists of Marls, gray-green shales and purple shales. 50 genus and 101 species of calcareous nannofossils have been recognised in the studied section. According to the index genus and species in the studied interval, calcareous nannofossil biozones CC25-CC26 have been recognized at the cretaceous sediments and NP1-NP5 and NTp1-NTp9 biozones have been determined at the Paleocene sediments that NP1-Np4 and NTp1-NTp7A biozones are reported for the first time from the upper part of Gurpi Formation at the studied section. With regard to these biozones, the age of the upper part of Gurpi Formation in the studied section is late Maastrichtian- late Danian (late early Paleocene) and the age of Pabdeh Formation is started from early late Paleocene. According to the nannofossil data, the K/Pg boundary is continuous and is located at the upper part of Gurpi Formation. The K/Pg boundary is marked by a decrease in abundance of Cretaceous species, increase in the abundance of Thoracosphaera operculata and the appearance of the new-Paleocene taxa. In the Danian sediments the Cretaceous species are present along with Paleocene species continuously and with a good preservation that can be considered as surviving species that may have passed the boundary and are present at the Danian sediments.
S. Senemari; Sh. Hasanpour
Abstract
Calcareous Nannofossils are good tool for biostratigraphy, especially in the Late Cretaceous. With respect to this and due to the lack of any precise paleontological study, the calcareous nannofossils of Ilam and Gurpi Formations were investigated in the Southwestern Sarvestan. These Formations consists ...
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Calcareous Nannofossils are good tool for biostratigraphy, especially in the Late Cretaceous. With respect to this and due to the lack of any precise paleontological study, the calcareous nannofossils of Ilam and Gurpi Formations were investigated in the Southwestern Sarvestan. These Formations consists of marl, clay limestone and shale. In this study, for the first time, 14 families, 22 genera and 39 species of nannofossils were identified. Based on the information obtained on nannofossils, the section is aged at Late Coniacian-Early Santonian to Early Maastrichtian corresponding to CC14-CC24 zones (Sissingh, 1977).
M. Azizi; S. Senemari
Abstract
Using calcareous nannofossils is a powerful way for biozonation in sub-stage level, especially in the Late Cretaceous and Cenozoic, because they are planktonic, cosmopolitan, abundant and have very short age. Considering lack of any precise paleontological studies about the Gurpi Formation in the NW ...
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Using calcareous nannofossils is a powerful way for biozonation in sub-stage level, especially in the Late Cretaceous and Cenozoic, because they are planktonic, cosmopolitan, abundant and have very short age. Considering lack of any precise paleontological studies about the Gurpi Formation in the NW of shiraz (Bavan), nannofossils chose to investigate. This Formation consists of shale, marl and limestone. In this study, 23 genera and 46 species of nannofossils were identified. According to the identified marker species, 14 biozones were diagnosed that classified as CC14-CC26 and NP1(Base of the Pabdeh Formation). According to these biozones, it has been suggested that this section is aged of the Gurpi Formation from Early Santonian to Danian. The existence of CC26-NP1 zonal marker species of the K/T boundary has been considered which indicates continuous sedimentation from the Late Cretaceous to Early Paleocene.
A. Mahanipour; A. Kani; M. H. Adabi; S. N. Raisossadat
Abstract
The Lower Cretaceous sedimentary succession of western Kopet Dagh Basin (Sarcheshmeh and Sanganeh formations) was investigated. Taking into account the considerable thickness of the studied section (1668 m) and the possibility of recording all the important events, determination of calcareous nannofossil ...
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The Lower Cretaceous sedimentary succession of western Kopet Dagh Basin (Sarcheshmeh and Sanganeh formations) was investigated. Taking into account the considerable thickness of the studied section (1668 m) and the possibility of recording all the important events, determination of calcareous nannofossil biostratigraphy was put on the agenda. This resulted in recognition of NC5, NC6 and NC7A nannofossil zones. Accordingly the age of the Sarcheshmeh Formation within the studied section is determined as Late Barremian- Early Aptian while the age of the Sanganeh Formation is late Early Aptian- early Late Aptian. The calcareous nannofossil assemblage of Sarcheshmeh and Sanganeh Formations has a Tethyan affinity with abundant warm-water varieties such as Rhagodiscus spp. and Nannoconus spp. while the cold-water species like Repagulumparvidentatum and Seribiscutum spp. are rare.
M. A. Sina; A. Aghanabati; A. L. Kani; A. R. Bahadori
Abstract
Calcareous nannofossils are suitable for biostratigarphical studies since they are abundant, planktonic, rapidly evolving and largely cosmopolitan, especially in the late Cretaceous. In this regards, 131 microscopic slides from shale and marl sediments of Gurpi formation of Poldokhtar section with thickness ...
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Calcareous nannofossils are suitable for biostratigarphical studies since they are abundant, planktonic, rapidly evolving and largely cosmopolitan, especially in the late Cretaceous. In this regards, 131 microscopic slides from shale and marl sediments of Gurpi formation of Poldokhtar section with thickness of 320 meters were collected. Out of this, 22 genera and 35 species were determined and their range chart is plotted. The distribution of nannofossil species indicates that there are 9 biozones in the study Poldokhtar section that can be separated, based on first occurrence (FO) of index species. They can be placed in CC18-CC26 of Sissingh (1977) time zones. On this basis, the age of sedimentation of this formation can be suggested to be from lower Companion to late Masstrichtian. In addition, presence of index species of low latitude in Poldokhtar section of Gurpi formation shows that this sedimentary basin was located in low latitude at the time of sedimentation.
saeedeh senemari; L. Fazli; M. Omrani
Abstract
Nannofossils and foraminifera planktonic have been short range stratigraphy and spread vast geographical because of that two fossils groups can be used for subdividing biostratigraphy. According to this, and due to the lack of any correlational paleontological study, the nannofossils of Gurpi Formation ...
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Nannofossils and foraminifera planktonic have been short range stratigraphy and spread vast geographical because of that two fossils groups can be used for subdividing biostratigraphy. According to this, and due to the lack of any correlational paleontological study, the nannofossils of Gurpi Formation have been investigated in north of Gachsaran. This formation has been formed of marl. As a result of this study and based on the obtained nannofossils and foraminifera planktonic, the studied section is Late Santonian to Late Maastrichtian in age, that corresponding to CC16-CC26 Zones (Sissingh, 1977) and Dicarinella asymetrica- Globotruncanita elevata Zone toAbathomphalus mayaroensis Zone (James & wind, 1985).
F. Hadavi; K. Khosrow Tehrani; S. Senemari
Abstract
Nannofossils are good for biostratigraphy, since they are abundant, planktonic, rapidly evolving and largely cosmopolitan especially in the Late Cretaceous. With respect to this reality and due to the lack of any precise paleontological study, the nannofossils of Gourpi Formation were investigated in ...
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Nannofossils are good for biostratigraphy, since they are abundant, planktonic, rapidly evolving and largely cosmopolitan especially in the Late Cretaceous. With respect to this reality and due to the lack of any precise paleontological study, the nannofossils of Gourpi Formation were investigated in the north of Gachsaran. This formation consists of marl and clay limestone.
In this study, for the first time, 23 genera and 43 species of nannofossils were identified. Based on the obtained nannofossils, the study section is Late Santonian to Late Maastrichtian in age corresponding to CC16-CC26.
