Stratigraphy and Palaeontology
Zeinab Manouchehri; Tayebeh Mohtat; Seyed Ali Aghanabati; Morteza Khalatbari Jafari; Fatemeh Vakil Baghmisheh
Abstract
The sediments are generally limestone and marl. The lower boundary with the loer red Formation is disconfomity and the upper boundary with the equivalent formatin of Bakhtiari Firmation is paraconformity. The total number of fossils found in this section is 69 species, 72 genera and 46 families. These ...
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The sediments are generally limestone and marl. The lower boundary with the loer red Formation is disconfomity and the upper boundary with the equivalent formatin of Bakhtiari Firmation is paraconformity. The total number of fossils found in this section is 69 species, 72 genera and 46 families. These sediments are formed in an open shelf and under the open sea and lagon environment. The variety and abundance of bentic foraminifer’s forms and the low presence of plagic forms testify to the shallow basin in this section, which is also confirmed by the study of other fossils. One of the Markable features of this section is the presence of Ammonia species, especially Ammonia parkinsonia. This section has a complete sequence of members of Qom Formation. This species are profe of shallow water and continental shelf for this carbonates. This section consist all of members of Qom Formation and based on identified foraminifera comparable to assemblage zone 1 & 2 introduced by Adams & Bourgeois (1967). These zones that inclod: 1-Borealis Melo Group- Meandropsin; 2- Miogypsinoides- Archaias- Valvulinid. Based on index foraminifer's species and their stratigraphic distribution the age of this section is Chatian- Burdigalian (Upper Oligocene-Lower Miocene)
Stratigraphy and Palaeontology
Ebrahim Mohammadi; Mohammad Javad Hassani
Abstract
Paleoecology of the Qom Formation ostracods in the Bojan and Varkan sections have been studied. The age of the sections has determined base on foraminifera and is Rupelian-chattian for the Bujan and Chattian for the Varkan Section. Ostracoda content of the Bujan and Varkan sections include 44 and 33 ...
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Paleoecology of the Qom Formation ostracods in the Bojan and Varkan sections have been studied. The age of the sections has determined base on foraminifera and is Rupelian-chattian for the Bujan and Chattian for the Varkan Section. Ostracoda content of the Bujan and Varkan sections include 44 and 33 species respectively. The pecies of genus Cytheridea are the most abundant and the most dominant ostracods of the Bujan section. In the lower part of the Bujan section, different species of Cytherella and Cytheridea constitute the dominant ostracods, but upward the abundance of Cytherella is declined and Cytheridea, Neonesidea, and Bairdia are dominant. Podocopids constitute 76% and 86% of the Bujan section ostracods during Rupelin and Chattian, respectively. Neonesidea elegans, Bythocypris pseudoreniformis, Paracypris pandyai, Paracypris sapperi and Paracypris naalunensis constitute the dominant ostracods of the Varkan Section. Podocopid ostracods are dominant in the Varkan marls and constitute 77% of the ostracods. The high percentage of podocopid ostracods indicates that the environment was oxygen-rich and without the ecological stresses in both section; while in the Varkan Section, the ecological conditions are stable but in the Bujan section, the oxygen enriches upward and ecological conditions become closer to normal marin basins.
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
shahram navavajary; Iraj Maghfouri Moghaddam; Ali Reza Shahidi; Hamid Nazari
Abstract
Oligo-Miocene rocks are deposited between Pyrenean and Pasadenian orogenic phases. This rocks in central Iran back arc deposits are named Qom formation. There are well developed outcrops of Qom formation at the North of Central Iran zone. In order to study microbiostratigraphy of the formation, Three ...
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Oligo-Miocene rocks are deposited between Pyrenean and Pasadenian orogenic phases. This rocks in central Iran back arc deposits are named Qom formation. There are well developed outcrops of Qom formation at the North of Central Iran zone. In order to study microbiostratigraphy of the formation, Three sections, north west of Darjazin town , Bonak mount and Arvaneh were selected. In these sections Qom formation with discontinuity overlays the Lower Red formation and with the same quality under the Late Miocene Conglomerate with intercalations of Sandstone, which is equivalent to the Upper Red Formation is placed. The main lithological composition of the Qom Formation in the study area alternates between layers of limestone and Marl with intercalations of siliciclastic rocks. Members and submembers of the Qom formation type area are not visible in this area and can only based on the lithological characteristics divide to local units. Based on bentic foraminifera and other microbiostratigraphical data, Qom Formation age in north west-west of Semnan (Darjazin-After zone), which is located in the Central Alborz structural- sedimentary zone, is early Miocene epoch and Burdigalian stage, which is the equivalent of Borelis melo curdica-Borelis melo biozone.
Stratigraphy and Palaeontology
Arash shabanpour Haghighie; Lida Bakhshandeh; Tayebeh Mohtat; Masood Zamanipedram; Seyed hamid Vaziri
Abstract
In this research the Gurpi Formation in the Zagros Basin outcropping in the Dasht-e Arjan section, Shiraz province ,for the purpose of biozonational and Paleobathymetric studies were investigated. The thickness of these sediments is about 130 m and consists of Limestones and Shales.To determine the palaeobathymetry ...
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In this research the Gurpi Formation in the Zagros Basin outcropping in the Dasht-e Arjan section, Shiraz province ,for the purpose of biozonational and Paleobathymetric studies were investigated. The thickness of these sediments is about 130 m and consists of Limestones and Shales.To determine the palaeobathymetry of the Gurpi Formation, Planktonic and benthic foraminifera were investigated . A depth of about 270m to 510m was determined for these sediments based on the ratio of planktonic foraminifera to the total assemblages of foraminifera after omitting infaunal benthic foraminifera (%P*) by using the equation D = e (3.58718+(0.03534 × %P* )).In this study sixty-two species of planktonic foraminifera belonging to eighteen genera were recognised .According to the studied planktonic foraminifera the Upper Cretaceous deposits in this area were divided into nine biozones as following :biozone1- Dicarinella concavata Interval Zone. Biozone2- Dicarinella asymetrica Total Range Zone. Biozone3- Globotruncanita elevata Partial range zone .Biozone4- Globotruncana ventricosa Interval Zone. Biozone5- Radotruncana calcarata Interval zone. Biozone 6- Globotruncanella havanensis Partial Range Zone. Biozone7- Globotruncana aegyptiaca Interval Zone. Biozone 8- Gansserina gansseri Interval Zone. Biozone 9- Contusotruncana contusa Interval ZoneBased on the studied planktonic foraminifera the Early Santonian to Maastrichtian ages were determined for the sediments .
Stratigraphy and Palaeontology
Fatemeh Vaez-Javadi; Mohammad Ali Ghanbarian
Abstract
Jurassic deposits are well spread in the north of Karim Abad village, north of Bahabad, central Iran. These deposits contain 41 species of palynomorphs, in which 15 spore species (12 genera), 15 pollen species (10 genera), and 10 species of dinocysts (3 genera) were identified. Vertical distribution ...
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Jurassic deposits are well spread in the north of Karim Abad village, north of Bahabad, central Iran. These deposits contain 41 species of palynomorphs, in which 15 spore species (12 genera), 15 pollen species (10 genera), and 10 species of dinocysts (3 genera) were identified. Vertical distribution of miospores allows erection within the Hojedk Formation of one biozone–Klukisporites variegatus- Chasmatosporites apertus Interval zone based on the FOO and LOO of selected taxa. Moreover, vertical distribution of dinoflagellate cysts allows erection within this formation of one biozone- Nannoceratopsis triceras-Nannoceratopsis gracilis Assemblage zone. The relative abundance of dinoflagellate cysts, spore, and pollen is 86.21%, 7.2%, and 6.6%, respectively. Therefore, the relative abundance of dinoflagellate cysts was high and the marine environment was prominent in this area during Jurassic sedimentation. Based on relative abundance of miospores' parent plant fossils, ferns, cycads, and conifers are 37%, 31.5% and 11.82%, respectively, and related sporomorph ecogroups (SEGs) indicate that they occurred in different environments such as upland, wetter / drier lowland, river and coastal with temperate-sub-tropical and humid climate.
Stratigraphy and Palaeontology
Nasrollah Abbassi; Majid Mirzaie Ataabadi; Mohammad Hasanpour
Abstract
A stratigraphic section from the upper part of Ziveh Formation (Middle Miocene) has been surveyed in north Ojagh Kandi village, northeast Kalibar, Azarbaijan province. Ziveh Formation overlayed by Tortonian sediments as an angular unconformity in the studied section and its lower boundary covered by ...
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A stratigraphic section from the upper part of Ziveh Formation (Middle Miocene) has been surveyed in north Ojagh Kandi village, northeast Kalibar, Azarbaijan province. Ziveh Formation overlayed by Tortonian sediments as an angular unconformity in the studied section and its lower boundary covered by recent alluvium. A diverse body fossil assemblage includes molluscan, plants, and vertebrate collected from this section. Among them, abundant ichnofossils of bivalves on woodground, Teredolites longissimus discovered in a horizon. Occurrence of wooden substrate in this horizon shows first events of rising of the sea level, and its basal background is considerable for the lower boundary for TST. On the other hand, Teredolites bearing horizon indicates beginig of transgressive event in the sequence stratigraphic interpretation of the studied section.
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
A. Shaabanpour Haghighi; , L. Bakhshandeh; T. Mohtat; , M. Zamani Pedram; S. H. Vaziri
Abstract
In this study the Upper Cretaceous sediments in the Zagrous Basins Fars province,the Pyrgheib Section,for the purpose of Biostratighraphy and sea level change studies were investigated. These sediments with about 206 m thickness consist of Limestone, Shale, Marl and limy marl. The investigated ...
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In this study the Upper Cretaceous sediments in the Zagrous Basins Fars province,the Pyrgheib Section,for the purpose of Biostratighraphy and sea level change studies were investigated. These sediments with about 206 m thickness consist of Limestone, Shale, Marl and limy marl. The investigated foraminifera led to identification of 70 species of planktonic foraminifera that belong to 16genera. Based on planktonic foraminifera the Upper Cretaceous deposits were divided into 6 biozone which are cosmopolitan and respectively are:biozone1 - Dicarinella concavata Interval Zone,Biozone2- Dicarinella asymetrica Total Range Zone,Biozone3- Globotruncanita elevata Partial range zone Biozone4- Globotruncana ventricosa Interval Zone,Biozone5- Radotruncana calcarata Interval zone. Biozone6- Globotruncanella havanensis Partial range zone ,Biozone7- Globotruncana aegyptiaca Interval zone. Biozone8- Gansserina gansseri Interval zone, Biozone9- Contusotruncana contusa Interval Zone. The Upper Cretaceous sediments in the study area on the basis of Planktonic Foraminifera are of the Late middle Coniacian to theLate Maastrichtian ages. According to the Morphotype groups of planktonic foraminifera deeping the basin from the Coniacian to the Middle Santonian is seen .However, in the late Santonian shallowing the basin and again in the Early Campanian deeping the basin, in the Late Campanian and close to the Campanian-Maastrichtian boundary shallowing the basin and a sea regression is observed.
Stratigraphy and Palaeontology
Hossein Gholamalian; Roya Fanati Rashidi
Abstract
Kazhdumi Formation strata in Anguran section (NW Bandar Abbas) are investigated and eight echinoid species belonging to eight genera have been identified. These species are: Tetragramma malbosii, Orthopsis ruppelli, Phyllobrissus aff. angustatus, Epiaster dartoni, Hemiaster sp., Pliotoxaster comanchei, ...
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Kazhdumi Formation strata in Anguran section (NW Bandar Abbas) are investigated and eight echinoid species belonging to eight genera have been identified. These species are: Tetragramma malbosii, Orthopsis ruppelli, Phyllobrissus aff. angustatus, Epiaster dartoni, Hemiaster sp., Pliotoxaster comanchei, Iraniaster douvillei, Coenholectypus planatus. Iraniaster douvillei that has already been reported from the Coniacian – Santonian beds of Lorestan Zone (West of Iran); is present in the Albian – Cenomanian strata of Anguran section. So; we can propose the new range of Middle Albian – Santonian for this species. Kazdumi Formation in the studied area has the age of Middle Albian to Early Cenomenian on the basis of foraminifers those accompany with echinoids. This formation conformably overlies the Dariyan Formation and disconfomably underlies the Gurpi Formation.
Stratigraphy and Palaeontology
Behzad Saeedi Razavi; mozhgan rikhtehgarzadeh; saeedeh senemari
Abstract
In order to study the biostratigraphy of Sarvak and Ilam in wells A1 and A2 of Binak oilfield, B of Gachsaran oilfield, C of Aghajari oilfield and D of Rag-Sefid oilfield, numerous thin sections have been studied microscopically In the biostratigraphic study of 5 biozones in the Sarvak and Ilam formations, ...
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In order to study the biostratigraphy of Sarvak and Ilam in wells A1 and A2 of Binak oilfield, B of Gachsaran oilfield, C of Aghajari oilfield and D of Rag-Sefid oilfield, numerous thin sections have been studied microscopically In the biostratigraphic study of 5 biozones in the Sarvak and Ilam formations, the following fields were introduced: 1-Oligostegina flood zone, 2- Nezzazata – Alveolinids assemblage zone, 3- Rudist debris zone, 4 -Nezzazatinella – Dicyclina assemblage zone, 5- Rotalia skourensis – algae assemblage zone and Oligostegina food zone. Based on the study of age of Sarvak Formation from Late Albian to Turonian, and for Ilam Formation from Coniasian to Santonian. Based on the biostratigraphy correlation and thickness analysis of biozones introduced in the two studied formations, the depth of the Zagros basin from northwest to southeast decreases dramatically.
Stratigraphy and Palaeontology
Manizhe Famarini Bozchalouei; Nasrollah Abbassi; Armin Salsani; Afshin Zohdi
Abstract
Soltanieh Formation comprises seven informal submembers as alternation of dolomites and shales, more than 1110 meters in thickness, was surveyed in the Seyedkandi section, 32 km southwest of Zanjan, northwest Iran. These submembers were subdivided as lower dolomite, lower shale, second dolomite, second ...
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Soltanieh Formation comprises seven informal submembers as alternation of dolomites and shales, more than 1110 meters in thickness, was surveyed in the Seyedkandi section, 32 km southwest of Zanjan, northwest Iran. These submembers were subdivided as lower dolomite, lower shale, second dolomite, second shale, third dolomite, upper shale and upper dolomite, respectively. Based on ichnological data from 109 specimens, 23 ichnogenera and 42 ichnospecies have been recognised. The abundance of trace fossils is very high in the second shale submember, so that 99 specimens were collected from this rock unit. Ichnofossil data from the studied section showsthat the Neoproterozoic-Cambrian boundary is located in the 8 m above the base of second dolomite submember in the studied section, where the first occurrence of Treptichnus pedum was been recorded.
Stratigraphy and Palaeontology
maryam naderiyan; elahe zarei; khadijeh Mohammad-khani
Abstract
The Dalichai Formation in Darjazin section in NE Semnan with a thickness of 631 meters consisting of an alternation of bulish-gray was studied. This formation overlies the Shemshak formation disconformity with conglomerate bed and it has gradually been covered by the thick-beded limestones of the Lar ...
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The Dalichai Formation in Darjazin section in NE Semnan with a thickness of 631 meters consisting of an alternation of bulish-gray was studied. This formation overlies the Shemshak formation disconformity with conglomerate bed and it has gradually been covered by the thick-beded limestones of the Lar formation. In order to study paleoenviroment of the Dalichai Formation the authors examined many different factors including Microfacies and palynological data (abundance and diversity of Dinocyst, proximate to chorat Dinocyst, palynofacies analysis and "selective preservation of organic matter"). A high percentage of brown wood and sporomorphs and the dominance of cavate and proximate dinocysts such as Nannoceratopsis gracilis, and pareodinia ceratophora and fluorescent amorphous organic matter, as well as Miliolid benthic foraminifera are evidence of suboxic to anoxic condition, which favored accumulation and preservation of organic matter in open marine lagoon, in the lower part of Dalichai Formation. A decrease in the brown wood and abundance and species richness of marine palynomorph (mainly chorate dinocysts) reflects more offshore settings in the upper part of Dalichai Formation. On the other hand, Appearance and increase of planktonic foraminifera and Radiolar and posidonia indicate development of strong marine transgression and deposition in an open marine environment.
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
Mahnaz Parvaneh Nejad Shirazi; M. Seddighi; P. Balicheh khorram abadi
Abstract
This study deals with lithostratigraphy, biostratigraphy, microfacies analysis, and depositional setting of the Jahrum Formation in Chellehgah Sepidan section, NW Shiraz. Vertical changes in lithological characteristics led to recognition of 15 lithotypes. The Jahrum Formation, in this area, rests conformably ...
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This study deals with lithostratigraphy, biostratigraphy, microfacies analysis, and depositional setting of the Jahrum Formation in Chellehgah Sepidan section, NW Shiraz. Vertical changes in lithological characteristics led to recognition of 15 lithotypes. The Jahrum Formation, in this area, rests conformably (with a gradational boundary) on the Pabdeh Formation and is overlain unconformably by the Asmari Formation. Micropaleontological analyses based on benthic foraminifera (Nummulites striatus, N. cf. fabianii, N. gr. bullatus-garganicus, Spiroclypeus sp.) suggest a middle-upper Eocene age for the formation. Facies analyses allowed to recognize the 6 facies (including 12 microfacies) for the examined strata. The results also suggest that the Jahrum Formation deposited in a homoclinal ramp.
Stratigraphy and Palaeontology
Mir Amir Salahi; Abbas Ghaderi; Alireza Ashouri; Ali asghar siabghodsi
Abstract
To separate the different units of the Paleogene sequences of the Kopet-Dagh basin and their regional correlation with the adjacent areas in the Central Asia, the Oyster bivalves fossils are used in the current research. Also, the study of their paleobiogeography has been considered in this study. Based ...
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To separate the different units of the Paleogene sequences of the Kopet-Dagh basin and their regional correlation with the adjacent areas in the Central Asia, the Oyster bivalves fossils are used in the current research. Also, the study of their paleobiogeography has been considered in this study. Based on this fauna, Pycnodonte-Oestra community in the Chehelkaman Formation uppermost parts represents the late Paleocene age and the first occurrence of Flemingostrea hemiglobosa at the base of the Khangiran Formation confirms the beginning of Eocene epoch. Association of different species and subspecies of Turkostrea in the Khangiran Formation demonstrates the middle part of early Eocene and Sokolowia community near the top of the Khangiran Formation shows the Lotetian-Bartonin ages. These features are in full compliance with the bivalve communities recorded from the other parts of Central Asia such as Amu-Darya, Farghana, Afghan - Tajik and Trim basin of China. It illustrates the same geological history of the mentioned areas during Paleogene, indicates the occurrence of different types of molluscan taxa in the Kopet-Dagh basin is the same as parallel horizons and equivalent time units throughout the extensive Central Asian region.
Stratigraphy and Palaeontology
faeze Amiri; E Zarei
Abstract
The Gurpi formation in Bishe-deraz Section, south of Ilam, consists of 201m marl with intercalations of limy marl with two formal members of Seymareh (Lopha) and Emam-Hasan. The formation overlies the Ilam Formation and is gradationally overlain by the purple shales of the basal part of the Pabdeh Formation. ...
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The Gurpi formation in Bishe-deraz Section, south of Ilam, consists of 201m marl with intercalations of limy marl with two formal members of Seymareh (Lopha) and Emam-Hasan. The formation overlies the Ilam Formation and is gradationally overlain by the purple shales of the basal part of the Pabdeh Formation. The Gurpi Formation was divided to 9 biozone on the basis of planktonic foraminifera which almost are cosmopolitan and consist of: 1- Radotruncana calcarata Taxon-Range Zone. 2- Globotruncanita stuartiformis Partial-Range Zone. 3- Globotruncana aegyptiaca Interval Zone. 4-Gansserina gansseri Interval Zone. 5- Contusotruncana contusa Interval Zone. 6- Abathomphalus mayaroensis Interval Zone. 7- Praemurica uncinata Interval Zone. 8- Morozovella angulata Interval Zone. 9- Globanomalina pseudomenardii Interval Zone. The formation was deposited from upper Campanian through late Paleocene (Selandian-Thanetian?) according to the planktonic foraminifera recorded. A distinct hiatus was confirmed at the Cretaceous-Paleogene boundary according to microbiostratigraphic and sedimentologic studies and also field work observation.
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
k. Khaksar
Abstract
This research has described for determinate of Oligo-Miocene Foraminifers at the Do Baradar section. The main aim project was scrutiny age of this Formation and Paleoecology distribution lot of basins have created with big streams between Zagros and Alborz with Central Iran. Final transgressive sea on ...
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This research has described for determinate of Oligo-Miocene Foraminifers at the Do Baradar section. The main aim project was scrutiny age of this Formation and Paleoecology distribution lot of basins have created with big streams between Zagros and Alborz with Central Iran. Final transgressive sea on the Rupelian to Late Miocene have created the continue sediments consist low depth Lime stone and Marls. These sediments have complete different colors and lithology have named Lower Red Formation and Upper Red Formation and total Qom Formation. In this section the thickness of Qom Formation is 830 Meters that 8 units can separate of Marls and Limestone. From the Limestone have collected a lot of Samples and on Marls have samples isolate Foraminifers. The result of this research have been showing: The Central Iran Sediments on the Rupelian to Burdigalian have a warm climate (Tropical) to sub warm (Subtropical) climate with restrict marine environment but continue to open sea. The depth on Oligo-Miocene was different and have swing.
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
Mahin mohamadi; R. Shabanian; H. M. Alizadeh
Abstract
This research has aimed to study the biostrtigraphy and lithostratigraphy of late cretaceous deposits in south of Maracan village , with 320 m thickness.This sequence overlaid the lower cretaceous deposits and have been covered by Quaternary sedimentary and magmatic rocks. Based on field ...
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This research has aimed to study the biostrtigraphy and lithostratigraphy of late cretaceous deposits in south of Maracan village , with 320 m thickness.This sequence overlaid the lower cretaceous deposits and have been covered by Quaternary sedimentary and magmatic rocks. Based on field study and lithological diversity 8 lithic zone have been investigated. 102 samples have been picked up systematically from this sequence. This study lead to determining 41 species from 15 genera of planktonic foraminifera.The systematic and classification of fauna are based on The (Postuma 1971) , (Caron1985) , (Loeblich and Tappan 1988) and (Permoli Silva And Verga 2004). .Based on their range chart the bio zonation model for this deposit with 9 Bio Zones as bellow have been suggested and have compared with cretaceous global standard bio zones (Robazynsky and Caron 1985) and (Permoli Silva and Verga, 2004) Dicarinella concavata Interval Zone (Robazynsky and Caron, 1995) Dicarinella asymetrica Total range Zone(Robazynsky and Caron, 1995) Globotruncanita elevata IntervalrangeZone(Robazynsky and Caron, 1995) Globotruncana ventricosa IntervalZone (Robazynsky and Caron, 1995) Rodotruncana calcarata Total range Zone(Robazynsky and Caron, 1995) Globotruncanella havnensis Partial Range Zone (Robaszynski and Caron, 1985) Globotruncana aegyptiaca Interval Zone (Robazynsky and Caron, 1995) Gansserina gansseri Interval Zone (Robazynsky and Caron, 1995) Abathamphalus mayaroensis Total range Zone(Robazynsky and Caron, 1995) The suggested age for th.is sequence based on planktonic foraminifera is upper coniantian to upper Maestrichtian and belong to deep shelf area . Based on the morphology of planktonic foraminifera and their keei we suggest deep sea environment for these deposits.
Stratigraphy and Palaeontology
Abbas Ghaderi; Mahdi Badpa; Ali Reza Ashouri
Abstract
To study of Permian corals at the northwest of Iran, Ali-Bashi stratigraphic section was selected and sampled. After microscopic studies of several longitudinal, transverse, and serial sections were obtained from more than 180 coral fossils, 12 species belonging to 6 genera of rogues and tabula corals ...
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To study of Permian corals at the northwest of Iran, Ali-Bashi stratigraphic section was selected and sampled. After microscopic studies of several longitudinal, transverse, and serial sections were obtained from more than 180 coral fossils, 12 species belonging to 6 genera of rogues and tabula corals were determined. The Permian succession of the Julfa area is the dominion of two types of coral fauna. Waagenophyllidae fauna that is the territory of the colonial coral forms comprises typically Tethyan indicators such as Ipciphyllum and Waagenophyllum with the age of Middle?- Late Permian. Cyathaxonia fauna, Late Permian in age, include terminal phylogenetic representatives of the rugose corals, mostly composed of solitary one Pentaphyllum. This genus is persistent till the vicinity of the extinction horizon at the near end Permian in the Ali Bashi Formation topmost horizon. Also, the last standing tabula coral before the Late Permian extinction in the Julfa region is the genus Protomichelinia. The Permian coral fauna of the NW Iran finely corresponds to those of the Abadeh region in Central Iran and Transcaucasus. The Waagenophyllidae forms are the same as South China fauna, whereas the Cyathaxonia ones reveal a high endemism in the Late Permian of NW Iran.
Stratigraphy and Palaeontology
Ghamarnaz Darabi; iraj Maghfouri Moghaddam; Abbas Sadeghi; Bizhan Yusefi
Abstract
In this study, biostratigraphy and Paleobathymetry of the Gurpi Formation in section southwest of Kuhdasht were studied. The thickness of Gurpi Formation in this section is 160 meters and its main lithology includes Marl, Limy Marl, Limestone and Shale. In this section Lower boundary of Gurpi Formation ...
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In this study, biostratigraphy and Paleobathymetry of the Gurpi Formation in section southwest of Kuhdasht were studied. The thickness of Gurpi Formation in this section is 160 meters and its main lithology includes Marl, Limy Marl, Limestone and Shale. In this section Lower boundary of Gurpi Formation is transition with Ilam Formation, and its upper boundary with Amiran Formation is unconformably. Here, on the basis of foraminiferal studies,50 species belonging to 24 genera of planktic foraminifera and Benthic were identified. Based on the stratigraphic distribution of the well known foraminifers, six foraminiferal biozones were established in the Gurpi Formation including: Globotruncana ventricosa Interval Zone, Radotruncana calcarata Taxon Range Zone, Globotruncanella havanensis Partial Range Zone, Globotruncana aegyptiaca Interval Zone, Gansserina gansseri Interval Zone, Contusotruncana contusa Interval Zone.The age of Gurpi Formation in this examined is determined based on identified biozones of Middel Campanian to Late Maastrichtian. A depth of 450 - 600 m was assigned for most parts of the sediments Gurpi Formatan was assigned ccording to planktic/epibenthic ratio and Percentage Morphotype 3 and the regression equation Depth = e (3.58718 + (0.03534 × %P*))
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
mahdi badpa; Hamed Yarahmadzahi; Kaveh Khaksar
Abstract
The Anarak Group with Zaladu (Gzhelian-Asselian age) and Tigh-e-Madanu (Sakmarian age) formations in the Ozbak Kuh Mountains (Central Iran) is more than 180 m thick and includes thick units of conglomerate, shale, sandstone, calcareous sandstone, sandy limestone, fusulinid limistone, marl and dolomite ...
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The Anarak Group with Zaladu (Gzhelian-Asselian age) and Tigh-e-Madanu (Sakmarian age) formations in the Ozbak Kuh Mountains (Central Iran) is more than 180 m thick and includes thick units of conglomerate, shale, sandstone, calcareous sandstone, sandy limestone, fusulinid limistone, marl and dolomite layers. In the sequence of Zaladu formation, the accumulation of coral species of Pseudozaphrentoides winsnesi Flügel, 1995, was abundantly identified in two horizons in the upper part of the Ghezelin layers. Based on fuanal composition, diversity and abundance, spacing of corallits and microfacies, the mentioned accumulation is categorized as low-level (of Type A, ecological zone of A2). This zone represents a tough ecological condition where only a limited number of solitary corals could have survived the life-threatening factors. Based on microfacies studies, the coral community was identified to be restricted to the shoal and around it (lagoon toward shoal and open sea toward shoal) in a shallow platform.
