A Mosavinia; K Seyed-Emami; A.A Aryai
Abstract
The Aitamir Formation follows conformably but with a sharp boundary the dark shales of Sanganeh Formation (Aptian-early Albian) and is followed discontinuously by the whitish marls and chalky limestones of the Abderaz Formation (Turonian-Coniacian). 7 species, 13 genera and 2 subgenera of ammonites are ...
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The Aitamir Formation follows conformably but with a sharp boundary the dark shales of Sanganeh Formation (Aptian-early Albian) and is followed discontinuously by the whitish marls and chalky limestones of the Abderaz Formation (Turonian-Coniacian). 7 species, 13 genera and 2 subgenera of ammonites are reported in this paper. The following genera and species, found in the Iranian Kopeh Dagh region, are reported for the first time: Anahoplites cf. praecox Spath, 1925, Anahoplites mantelli Spath, 1925, Epihoplites aff. trifidus (Spath, 1923) and Hysteroceras orbignyi (Spath, 1922). The described specimen of Dinosauria comes from the upper part of the Aitamir Formation in Zawin Section. The fragment of the Dino was found on the topmost sandstone layer of the section, together with a number of mortonoceratid ammonites, indicating a late Albian (Mortoniceras inflatum Zone) age. So far, it is the first record of marine Dinosauria from the Certaceous of Iran.
F. Dabbaghi Sadr; K. Seyed-Emami; M. Majidi Fard
Abstract
Upper Jurassic rocks are well developed at the western part of the Binalud Range (northeast Iran). These consist mainly of limestone, marlstone and marl with few intercalations of sandstone and conglomerate. The thickness of this succession in the study section (Bormahan, northwest of Neyshabour) ...
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Upper Jurassic rocks are well developed at the western part of the Binalud Range (northeast Iran). These consist mainly of limestone, marlstone and marl with few intercalations of sandstone and conglomerate. The thickness of this succession in the study section (Bormahan, northwest of Neyshabour) is 1084 meters and can be subdivided into 6 members. The lower boundary with the dark siliciclasts of ?Kashafrud Formation (Upper Bajocian / Lower4 Bathonian) is sharp. The upper boundary with buff and cliff-forming carbonates of the ?Mozduran Formation (Upper Jurassic) is transitional. Ammonites are the most important and abundant macrofossils.Totally more than 300 specimens have been collected, comprising 21 genera and 36 species.The relative abundances at the family level are: Phylloceratidae (48%), Perisphinctidae (42%), Oppeliidae (6%), Haploceratidae (2%), Aspidoceratidae (1%) Based on the ammonite fauna 15 biozones are recognized which can be fairly good compared with the ammonite biozonation of Sub-Mediterranean Province. According to the ammonite fauna an Early Bathonian to Kimmeridjian age is proposed.The ammonite fauna is closely related to those of the Sub-Mediterranean Province, indicading a permanent faunal exchange.
Ali Shekarifard; F. Baudin; K. Seyed-Emami; J. Schnyder; H. Rahimpour-Bonab
Abstract
Geochemical characteristics (Rock-Eval pyrolysis and elemental analysis of kerogen), palynofacies and organic petrography (using light transmitted-reflected-uv microscopy) of the basal black shale from the Shemshak Group (Upper Triassic- Middle Jurassic) in the Tazareh section (Eastern Alborz) have been ...
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Geochemical characteristics (Rock-Eval pyrolysis and elemental analysis of kerogen), palynofacies and organic petrography (using light transmitted-reflected-uv microscopy) of the basal black shale from the Shemshak Group (Upper Triassic- Middle Jurassic) in the Tazareh section (Eastern Alborz) have been investigated. The basal black shale is rich in amorphous organic matter with fewer amounts of vitrinite particles that was deposited in lacustrine environment under anoxic to suboxic conditions. According to vitrinite reflectance values (mean VRr=2.1%), organic matter of the basal black shale has experienced high thermal maturity during deep burial. In this study samples residual organic carbon content is 1 wt.% on average. Thermal modeling results using 1D Genex4 software show that the basal black shale of the Shemshak Group became mature during the Middle Jurassic-Lower Cretaceous time and generated hydrocarbon. At the present day, this organic facies in the Tazareh section is thermally over-mature and depleted in hydrogen and is located in the dry gas generation window. Presently, these sediments are considered as shale gas resources.
K. Seyed Emami; N. Behfar; M. R. Majidifard; A. Behfar
Abstract
Middle Jurassic strata are well developed northeast of Damghan (E Alborz). At the study section the Dalichai Formation has a maximum thickness of 156 m, consisting of an alternation of bluish-grey limestones and marls, being subdivided into 4 members. The lower boundary with the siliciclastics of the ...
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Middle Jurassic strata are well developed northeast of Damghan (E Alborz). At the study section the Dalichai Formation has a maximum thickness of 156 m, consisting of an alternation of bluish-grey limestones and marls, being subdivided into 4 members. The lower boundary with the siliciclastics of the underlying Shemshak Formation is unconformity, due to the Mid-Cimmerian tectonic event, whereas the upper boundary with the light and cliff-forming carbonates of the Lar Formation is gradational. The Dalichai Formation at the study section is very fossiliferous. Summing up 1750 fossil specimens were collected, among which the ammonoids with 1491 specimens clearly predominate. Altogether 27 genera, 33 species of ammonites, belonging to 6 biozones (Parkinsoni Zone, Zigzag-Aurigerus zones, Subcontractus Zone, Bullatus-Gracilis zones, Anceps-Coronatum zones, Athleta Zone) has been recognized. In addition 17 genera and 8 species of planktonic and benthic foraminifers are described.These can be divided into 2 biozones. The fossil-content is mainly concentrated within few meters of red and nodular limestone in the upper part of the section. Based on the ammonite fauna the age of the Dalichai Formation in the investigated area ranges from Upper Bajocian to Oxfordian. Paleobigeographically the fauna shows close relationship to western Europe and Sub-Mediterranean region. This indicates a paleogeographic position of the area at the northern Tethys during the Middle-Upper Jurassic.
M. Shams; K. Seyed-Emami
Abstract
The Dalichai Formation and its ammonite fauna is studied for the first time in the Parvar area, Central Alborz. At Parvar the Dalichai Formation, with a thickness of about 70 m, consist of an alternation of grayish silty marls, marlstones, marly limestone and limestone and is subdivided into 5 members. ...
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The Dalichai Formation and its ammonite fauna is studied for the first time in the Parvar area, Central Alborz. At Parvar the Dalichai Formation, with a thickness of about 70 m, consist of an alternation of grayish silty marls, marlstones, marly limestone and limestone and is subdivided into 5 members. A rich ammonite fauna (407 specimens) have been collected from the member 4 and 5, comprising the following families: Phylloceratidae, Lytoceratidae, Oppeliidae, Haploceratidae, Sphaeroceratidae, Parkinsoniidae, Morphoceratidae and Perisphinctidae. These indicate a Late Bajocian and Bathonian age. Member five consists of greenish to reddish, nodular and flaggy limestones and is a typical condensed horizon.
R. Azimi; K. Seyed-Emami; A. Sadeghi
Abstract
The calpionellid biozonation within Shal and Kolur Formations in Shal region, SE Khalkhal are accomplished based on standard biozonation of Allemann et al. (1977). In this study, 5 biozones are introduced from Tithonian to Hauterivian:biozone. Biozone 1 belongs to Shal Formation ...
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The calpionellid biozonation within Shal and Kolur Formations in Shal region, SE Khalkhal are accomplished based on standard biozonation of Allemann et al. (1977). In this study, 5 biozones are introduced from Tithonian to Hauterivian:biozone. Biozone 1 belongs to Shal Formation and biozones 2 to 5 to Kolur Formation: 1- Crassicollaria intermedia Taxon Range Zone; Late Tithonian, 2- Calpionella alpina Acme Zone; Early Berriassian, 3- Calpionellopsis simplex - Calpionellites darderi Interval Zone; Late Berriassian to Early Valanginian, 4- Calpionellites darderi - Tintinopsella longa Interval Zone; Valanginian, 5- Tintinopsella longa - Tintinopsella carpathica Interval Zone; Late Valanginian- Hauterivian. Biozone 2 is also subdivided into the Calpionella alpina and Calpionella elliptica Subzones. Biozone 3 is subdivided into the Calpionellopsis simplex and Calpionellopsis oblonga Subzones. Based on this zonation, the Jurassic /Cretaceous boundary (Tithonian/ Berriassian) is defined at the Lower boundary of the Calpionella alpina zone which is equivalent to the Shal and Kolour Formations boundary.
