Stratigraphy and Palaeontology
marjan zadesmaeil; Mahmoud Reza Majidifard; Seyed Hamid Vaziri; Davood Jahani
Abstract
The Middle and Upper Jurassic sedimentary well successions is located in the northwestern Damghan, (eastern Alborz range). The Dalichai Formation with a thickness of 618 meters in the studied section consists of marl, limestone and marly limestone. The lower boundary with the siliciclastic of the underlying ...
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The Middle and Upper Jurassic sedimentary well successions is located in the northwestern Damghan, (eastern Alborz range). The Dalichai Formation with a thickness of 618 meters in the studied section consists of marl, limestone and marly limestone. The lower boundary with the siliciclastic of the underlying Shemshak Formation is unconformable and in the upper boundary is gradually covered by the Lar Formation. From studied section, altogether 371 fossile sample were collected of which 15 sample were related to other taxon (Bellemnite, Bivalve, Coral and Sponge). Altogether, 51 species of ammonites from the Dalichai Formations belonging to 25 genera and 9 families and 14 zones are described. The following families are reported: Phylloceratidae, Lytoceratidae, Haploceratidae, Oppeliidae, Parkinsoniidae, Morphoceratidae, Reineckeiidae, Perisphinctidae and Aspidoceratidae.Based on ammonites, the Dalichai Formation ranges from the Upper Bajocian to Lower Kimmeridgin and can be subdivided, from bottom to top, into six informal members.Palaeobiogeographically the ammonite fauna is closely related to that of the sub-Mediterranean Province of the northwestern Tethys.
Stratigraphy and Palaeontology
Tayaebe Sarbandi Farahani; Mehdi Yazdi; Mahmoud Reza Majidifard
Abstract
The present study deals with the ammonites from the upper part of the Chaman Bid Formation, member 4 (Middle-Upper Jurassic) at the type locality. Lithostratigraphicall, it is consites alternation of limestone and marls.Following ammonite families are present: Perispinctidae, Ataxioceratidae, Haploceratidae, ...
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The present study deals with the ammonites from the upper part of the Chaman Bid Formation, member 4 (Middle-Upper Jurassic) at the type locality. Lithostratigraphicall, it is consites alternation of limestone and marls.Following ammonite families are present: Perispinctidae, Ataxioceratidae, Haploceratidae, Oppeliidae and Aspidoceratidae, which indicate the Biozones: Hybonoticeras hybobotum , Semiformiceras semiforme , Semiformiceras fallauxi , Microcanthoceras ponti and Micracanthoceras micracanthum Zones. Paleobiogeographicall, the ammonite fauna is closely related with the Submeditteranean Provice, with few affinities to South Tethys (Ethiopian province ),migrated during the Tithonian. Following taxa are reported for the first time fromthe Tithonian strataNorth Iran: Zappalia cf. zapalensis, Paraulacosphinctes transitorios, P. seneoides.
Stratigraphy and Palaeontology
Tayebe Sarbandi Farahani; Mehdi Yazdi; Mahmoud Reza Majidifard
Abstract
This paper focused on the systematic of the benthic foraminifera from the Chaman Bid and Goznawwi sections. At the type locality of the Chaman Bid Formation, consists of alternation of limestone (grainstone to wackstone), argilasious limestone and marl. The age of tha Chaman Bid Formation based on ammonite ...
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This paper focused on the systematic of the benthic foraminifera from the Chaman Bid and Goznawwi sections. At the type locality of the Chaman Bid Formation, consists of alternation of limestone (grainstone to wackstone), argilasious limestone and marl. The age of tha Chaman Bid Formation based on ammonite fauna range from ?Bathonian to late Tithonian. and the age. Near the Azadshar, the Farsian Formation is exposed and consists of fossilferous the soft marl, sandstone, limestone and silt which based on ammonite, age of this sediment considered as Callovian. Two studied sections are bearing well - preserved foraminifera which most belong to Lagenina (most belong to Nodosaridae and Vaginolinidae families) and Rotalina (Epistominidae); total 23 genus and 39 species from Goznawwi and 10 genus and 16 species from Chaman Bid sections. The 28 species of the benthic isolated foraminiferal assemblages are first recorded from Iran. In additional, based on this study, Iranian assemblage of foraminifers at this time are most similar to those of the North of the tetyan releam.
Stratigraphy and Palaeontology
Fateme Mahdikhani; Mahmoud Reza Majidifard; T. Mohtat; L. Bakhshande; M. Zamanipedram
Abstract
In order to study the biostratigraphy and lithostratigraphy of the K/Pg boundary two sections was considered. They are the Kuh-e Zaluband and Kuh-e Hunu sections in east of Khur (Esfehan Province). At the Kuh-e Zaluband section has a maximum thickness of 100 m, consisting of marl, limestone, sandy limestone, ...
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In order to study the biostratigraphy and lithostratigraphy of the K/Pg boundary two sections was considered. They are the Kuh-e Zaluband and Kuh-e Hunu sections in east of Khur (Esfehan Province). At the Kuh-e Zaluband section has a maximum thickness of 100 m, consisting of marl, limestone, sandy limestone, sandstone and conglomerate and in the Kuh-e Hunu consisting of marl, limestone and sandy limestone. The lower part of the sections belonging to Farrokhi formation and upper part to Chupanan formation. Based of biostratigraphy at the study sections, summing up 88 thin sections were collected, among which the foraminifera with 17 specimens clearly predominate and belonging to 31 genera. Based on the foraminifera the age of the upper part of Farrokhi formation in the investigated area ranges Late Maastrichtian and Late Paleocene for lower part of Chupanan formation. Based on the paleontology, lithology and facies, there is disconformity in Cretaceous-Paleogene boundary in Kuh-e Zaluband and paraconformity in Kuh-e Hunu.
Seyed Hamid Vaziri; Mahmoud Reza Majidifard; Marc Laflamme
Abstract
The Precambrian Kushk Series in the Bafq and Behabad regions of Central Iran contains a diverse assemblage of latest Ediacaran fossils that showcase a fossil assemblage much more diverse than typically known from the latest Ediacaran systems worldwide. The Kushk Series reaches a thickness of >500 ...
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The Precambrian Kushk Series in the Bafq and Behabad regions of Central Iran contains a diverse assemblage of latest Ediacaran fossils that showcase a fossil assemblage much more diverse than typically known from the latest Ediacaran systems worldwide. The Kushk Series reaches a thickness of >500 m and consists of carbonate (sandy dolomitic limestone and dolomite) and siliciclastic (shale, sandstone, and siltstone) facies with extensive accumulations of volcanic rhyolite, microdiorite, and tuff, which its argillaceous shales contain an assemblage of abundant Ediacaran fossils including Kuckaraukia multituberculata,Persimedusites chahgazensis, Corumbella werneri, Cloudinasp., Chuaria sp., Kimberella persii, Gibbavasis kushkii, Erniettomorpha, Rangeomorpha and numerous tubular organisms. The discovery of classic terminal-Ediacaran index fossils Cloudina and Corumbella in this assemblage confirms a latest Ediacaran age (Nama-Assemblage ~545-539 Ma) for these deposits. These taxa help expand our understanding of the latest Ediacaran prior to the Ediacaran extinction and the Cambrian explosion of complex animals.
Sh. Nouri; E. Ghaseminejad; M. R. Majidifard
Abstract
The Sanganeh Formation is one of the Early Cretaceous rock units in the Koppeh- Dagh basin. This formation in the Dahaneh Gholaman section (in north of Bojnord city) with a thickness of 900 meters (consist of marl, shale and limestone) is laying conformably on the Sarcheshmeh Formation and covered by ...
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The Sanganeh Formation is one of the Early Cretaceous rock units in the Koppeh- Dagh basin. This formation in the Dahaneh Gholaman section (in north of Bojnord city) with a thickness of 900 meters (consist of marl, shale and limestone) is laying conformably on the Sarcheshmeh Formation and covered by Atamir Formation. In this study, biostratigraphic investigations on 50 palynological samples from the Sanganeh Formation led to recognition of 21 genera and 31 species of dinoflagellate cysts indicating an age of Late Aptian-Albian belonging to Odontochitina operculata zone. Also palynofacies studies revealed two types of palynofacies (II and IV). Palynofacies studies show dominance of palynofacies II through the stratigraphic column indicating a marginal dysoxic-anoxic basin. On the other hand, presence of palynofacies IV in some parts along the stratigraphic column reflects increase in the depth of the marine environment from time to time.
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.