List of Articles Cretaceous

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  1 - ‍Calcareous algae of the Shah Kuh Formation (Early Cretaceous) in southwest of Khur (Central Iran)
  hamid mirmohammadsadeghi  Adabi  
  A complete succession of the Shah Kuh Formation with the age of Early Cretaceous is exposed in southwest of Khur, in Central Iran. In order to study and describe calcareous algae the Shah Kuh Formation a stratigraphic section was selected, sampled and studied in Kuh- e More

  A complete succession of the Shah Kuh Formation with the age of Early Cretaceous is exposed in southwest of Khur, in Central Iran. In order to study and describe calcareous algae the Shah Kuh Formation a stratigraphic section was selected, sampled and studied in Kuh- e Tangal- e Bala, 80 Km southwest of Khur city. Association of calcareous algae consist of Delloffrella quercifoliipora belongs to Triploporellaceae, Montiella elitzae, Neomeris cretacea, Salpingoporella sp. and Terquemella sp. related to Dasycladacea and Permocalculus cf. minutus belongs to Gymnocodiacea. Also 2 genera of Udoteaceae (Arabicodium and Boueina) and 1 species of Solenoporaceae (Marinella Lugeoni) were identified. A species of algae ascribed to uncertain affinities (Lithocodium aggregatum) accompanied by skeletal fragments of colonial octocorals were identified in this research. In studied microfacies, ‍calcareous algae were observed in sediments of lagoon and bar environments. Based on ‍calcareous algae and benthic foraminifera association, the age of Late Barremian- Early Aptian was assigned for the succession of the Shah Kuh Formation in studied section. Manuscript profile
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  2 - Biostratigraphy of Mesozoic-Cenozoic boundary based on calcareous nannofossils in Bulfars section, Southwest Iran
  Saeedeh Senemari
  To study Mesozoic –Cenozoic boundary based on calcareous nannofossils, section of Tang-e- Bulfars in East Ramhormoz was studied. The fossil groups in determining the relative age of the Mesozoic and Cenozoic layers are important. In this interval, a thickness of 32 m More

  To study Mesozoic –Cenozoic boundary based on calcareous nannofossils, section of Tang-e- Bulfars in East Ramhormoz was studied. The fossil groups in determining the relative age of the Mesozoic and Cenozoic layers are important. In this interval, a thickness of 32 meters of shale and limestone were studied and for the first time 35 species of nannofossils were identified. As a result, the identified biozones includes Reinhardtites Levis Zone (UC18/CC24) and the base of Arkhangelskiella cymbiformis (CC25/UC19) with Late Cretaceous age and Heliolithus kleinpellii Zone (NP6) with Selandian/Thanetian age. Based on the identified zones, the transition period of Early Maastrichtian-Selandian/Thanetian and the boundary between the Cretaceous to Paleogene was determined as a discontinuity. The presence of index species of calcareous nannofossils indicates that the studied sediments in the section of Tang-e- Bulfars were deposited in the lower latitudes and under warm climatic conditions. . Manuscript profile
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  3 - Late Cretaceous Island-arc subduction magmatism in northern edge of central Iran, SW Sabzevar
  Elham Mirzakazemi Habibollah Ghasemi Fardin Mousivand Wilyam Griffin
  A thick sequence of Late Cretaceous volcano-sedimentary rocks crops out on the northern margin of Central Iran, in the southwest of the Sabzevar. The igneous rocks include extrusions (trachy-andesite, dacite and rhyolite) and shallow depth intrusions (gabbro, gabbrodior More

  A thick sequence of Late Cretaceous volcano-sedimentary rocks crops out on the northern margin of Central Iran, in the southwest of the Sabzevar. The igneous rocks include extrusions (trachy-andesite, dacite and rhyolite) and shallow depth intrusions (gabbro, gabbrodiorite, diorite and granite). These igneous rocks have geochemical signatures of magmatic rocks of island-arc subduction zones and plot within field in different tectonic setting discrimination diagrams. The parental magma of these rocks has island arc tholeiitic nature and was produced via partial melting of a depleted spinel lherzolite mantle source during closing of the Sabzevar Neo-Tethyan oceanic basin in the Late Cretaceous. This depleted mantle source was affected by the metasomatic fluids released from dehydration of the Neo-Tethys subducted oceanic slab. Manuscript profile
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  4 - Microfacies and sedimentary environment of Lower Cretaceous deposits in Qumenjan section, south west of Qayen
  Hourieh Zarei Seyed Naser Raisossadat M. Mortazavi M. Yazdi
  In order to study the Lower Cretaceous deposits, Qumenjan section has been selected and measured. Field and lab studies of the Lower Cretaceous deposits in this section reveal a gradual change of the depositional setting, from a fluvial depositional system (continental More

  In order to study the Lower Cretaceous deposits, Qumenjan section has been selected and measured. Field and lab studies of the Lower Cretaceous deposits in this section reveal a gradual change of the depositional setting, from a fluvial depositional system (continental environment) to a mixed siliciclastic- carbonate ramp (marine environment). The continental deposits of the studied section include conglomerate and sandstone lithofacies that are deposited in a proximal gravel- bed braided river. In the studied sedimentary sequence, the marine siliciclastic- carbonate facies associations are formed in three tidal flat, lagoon and shoal facies belt in the inner and mid ramp setting. Manuscript profile
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  5 - Temporal- spatial analysis of sedimentary environments of the Upper Cretaceous carbonate deposits in the Bajestan area (North of Lut Block)
  Zahra Rezazadeh Mahmoud Jalali Mahbobeh Hosseni- Barzi Ahmad- Reza Khazaee
  In this study, microfacies, sedimentary environment and sedimentary model of the Upper Cretaceous carbonate deposits in the Bajestan region were studied and analyzed in four sections Chachool, Shahrak Sanati, Mazar and Bahabad. These deposits are exposed in different se More

  In this study, microfacies, sedimentary environment and sedimentary model of the Upper Cretaceous carbonate deposits in the Bajestan region were studied and analyzed in four sections Chachool, Shahrak Sanati, Mazar and Bahabad. These deposits are exposed in different sections with different thicknesses. Based on sedimentary texture, petrographic and biotic evidences, 6 carbonate microfacies belonging to three facies belts of lagoon, shoal and shallow open marine located on the inner ramp were identified in these deposits. Comparison of microfacies and facies zones of different sections show a slight and gradual increase in the depth of Cenomanian and a significant increase in Santonian- Early Campanian relative to Cenomanian. Furthermore, the depth of these sediments in Chachool and Shahrak Sanati sections is almost similar and shallower than the others, while Mazar and Bahabad sections represent deeper environment. Accordingly, the approximate coastline trend seems to be east, northeast- west, southwest. However, the presence of different amounts of siliciclastic sand in some facies could be related to the tectonic activity along the basement faults in the area. Manuscript profile
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  6 - Sudden drowning of the Late Cretaceous carbonate platform in central Zagros basin: a case study from the shaley Laffan Member in one of the Oil Fields of Abadan Plain, SW Iran
  maryam kianifard علی حسین  جلیلیان nasser arzani
  Rapid sea-level rise and drowning of carbonate platforms is one of the important geological events in the Late Cretaceous and after the Turonian global unconformity. This transgression in central and western Zagros Basin is represented as shaley sediments of the Laffan More

  Rapid sea-level rise and drowning of carbonate platforms is one of the important geological events in the Late Cretaceous and after the Turonian global unconformity. This transgression in central and western Zagros Basin is represented as shaley sediments of the Laffan Member, which were deposited over the Sarvak Formation. The stratigraphic position and the occurrence of the Charophytes-Ostracods biozone indicate the late Cretaceous, Coniacian age for the Laffan Member, which is stratigraphically equivalent to the Surgah Formation in Lurestan area in the west of Iran. The Laffan Member is mainly shaley in lithology with intercalations of thin-bedded argillaceous limestones and is the caprock over the reservoir of the Sarvak Formation in some oil fields in SW Zagros. Microfacies, sedimentary environments, biostratigraphy and sequence stratigraphy of the Laffan Member in two wells of Azadegan Oil Field located in Abadan Plain were investigated. Petrographic data revealed the presence of a shaley facies and two carbonate microfacies including charophitic mudstone-wackestone to bioclastic planktonic foraminiferal wackestone. These microfacies were deposited in transitional-brackish to deep marine environments. Marine transgression over the eroded palaeotopography of the Cenomanian-Toronian carbonates resulted in estuaries as channels and transitional environments. In these estuaries, mixture of the fresh and marine waters resulted in deposition of the lower parts of the Laffan Member and graded upward into the marine deposits of the upper parts of this Member.The sudden change of shallow-transitional facies to deep marine sediments in the Laffan Member indicates drowning of the carbonate platform of central Zagros Basin in Coniacian. The evidence like erosional base, deepening-upward sequences, frequency of mudstone facies (shale) and continuity with marine carbonates confirm this conclusion. Investigation of vertical changes of the microfacies with gama-ray well log data indicate the Laffan Member is part of a sequence as lowstand deposits (LST), transgressive deposits (TST) which grade upwards into maximum flooding surface (MFS) and high-stand deposits (HST) which comprise a third-order sequence. This sequence begins with an erosional unconformity and follows up with the formation of the estuary and deep sea sediments. The latter package is covered with the carbonate sediments of the lower part of the Ilam Formation (Santonian) which represents carbonate platform deposits of high-stand system track (HST). Manuscript profile
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  7 - Calcareous nannofossil biostratigraphy in the upper part of the Garau Formation in the Sheikh Saleh section in Northwest of Kermanshah, Lurestan Province (Zagros Basin)
  سعیده  سنماری
  In this study, the upper part of the Garau Formation with a thickness of 24 m in the section of Sheikh Saleh anticline located in the northwest of Kermanshah was investigated from the calcareous nannofossils. In this section, the Garau Formation is mainly composed of me More

  In this study, the upper part of the Garau Formation with a thickness of 24 m in the section of Sheikh Saleh anticline located in the northwest of Kermanshah was investigated from the calcareous nannofossils. In this section, the Garau Formation is mainly composed of medium bedded argillaceous limestone. In order to introduce the index species and biozones, 17 slides from the Garau Formation were studied, which resulted in the identification of three biozones. As a result of this study, 20 species and 15 genera of calcareous nannofossils were identified. Based on the obtained biozones, the age of the upper part of the Garau Formation in the studied section is suggested the late early Cenomanian to the late late Cenomanian. This age is corresponding to the upper part of Eiffellithus turriseiffelii Zone (CC9), Microrhabdulus decorates Zone (CC10), lower part of Quadrum gartneri Zone (CC11) from the Sissingh (1977) zonation and UC1, UC2, UC3, and lower part of UC7 from the Burnett (1998) zonation. Manuscript profile
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  8 - Biostratigraphy of the Cretaceous/ Paleogene boundary in the Chahardeh section (Izeh zone, Khuzestan province)
  نسرین  هداوند خانی عباس  صادقی علیرضا  طهماسبی محمد حسین  آدابی
  Abstract In order to study of Cretaceous/ Paleogene (K/Pg) boundary in the Izeh zone-Chahardeh section, 100m of sediments at the top of Gurpi Formation are collected during geological sampling. These sediments mainly consist of green shale and marl of Gurpi Formation More

  Abstract In order to study of Cretaceous/ Paleogene (K/Pg) boundary in the Izeh zone-Chahardeh section, 100m of sediments at the top of Gurpi Formation are collected during geological sampling. These sediments mainly consist of green shale and marl of Gurpi Formation. On the basis of the identified planktonic foraminiferal assemblages, six biozones are recorded: - Plummerita hantkenoides Zone (CF1), (Late Maastrichtian) - Guembelitria cretacea Partial-range Zone (P0), (Danian) - Parvularugoglobigerina eugubina Taxon-range Zone (Pα), (Danian) - Eoglobigerina edita Partial-range Zone (P1), (Danian) - Praemurica uncinata Lowest-occurrence Zone (P2), (Danian) - Morozovella angulata Lowest-occurrence Zone (P3), (Danian-Selandian) Based on above mentioned biozones, the Cretaceous/ Paleogene (K/Pg) boundary in this section located on 79m lower than Pabdeh/Gurpi Formations boundary. The biostratigraphic correlations based on planktonic foraminiferal zonations showed a comparison between the biostratigraphic zones established in this study and other equivalents of the commonly used planktonic zonal scheme around the Cretaceous/ Paleogene boundary in Tethys. Manuscript profile
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  9 - Biostratigraphy of Dariyan Formation in Lar Anticline (north east Gachsaran) and Lower Cretaceous sediments in Kolah Ghazi section (South west Isfahan)
  Mahdie Shirzad Hosyen Vaziri moghadam Ali Bahrami
  In order to identify foraminifera and determine the age of Dariyan Formation and the lower Cretaceous sediments of Central Iran, a section of Dariyan Formation in Lar Anticline (northeast Gachsaran) (with a thickness of 111m, thick, medium and thin layer of limestone, m More

  In order to identify foraminifera and determine the age of Dariyan Formation and the lower Cretaceous sediments of Central Iran, a section of Dariyan Formation in Lar Anticline (northeast Gachsaran) (with a thickness of 111m, thick, medium and thin layer of limestone, marl and marly limestone) and Kolah Ghazi section (south west Isfahan) (with a thickness of 260m, thick to medium layer limestone and shale) were studied. Based on biostratigraphic studies of Lar Anticline section, 28 benthonic foraminifera and 4 planktonic foraminifera have been identified in 4 biozones contains: Hedbergellids - Orbitolinids assemblage zone, Mesorbitolina texana zone, Mesorbitolina gr. subconcava zone, Favusella washitensis rang zone. Based on biostratigraphic of Lower Cretaseous sediments in Kuh-e-Kolah Ghazi, 21 benthonic foraminifera and 1 planktonic foraminifera have been identified and consequently 2 biozones are recognized contains: Mesorbitolina texana zone, Mesorbitolina gr. subconcava zonethe studied areas were correlated with some sections of the Dariyan in Kuh-e-Fahliyan, Kuh-e- Mangasht and Meymand. Accordingly, the sedimentation of two studied sections in Lar Anticline and Kuh-e-Kolah Ghazi were started from Late Aptian which were later than the other sections, and the end of sedimentation in the Kuh-e-Kolah Ghazi was earlier than the other sections in the Late Aptian age, while the end of sedimentation of Dariyan Formation in other sections was in Early Albian age Manuscript profile
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  10 - Biostratigraphy and paleoecology of Family Gavelinellidae in Sanganeh and Aitamir Formations at the Kopeh-Dagh basin
  Maryam Motamedalshariati Mahmoud Jalali
  10.61186/ispg.41339.11.22.89
  The sedimentary basin of Kopeh-Dagh is located in the northeast of Iran. This sedimentary basin has been of interest for a long time because of hydrocarbon materials. Gavelinellids are the most abundant and dominant groups of benthic foraminifera in epicontinenal seas d More

  The sedimentary basin of Kopeh-Dagh is located in the northeast of Iran. This sedimentary basin has been of interest for a long time because of hydrocarbon materials. Gavelinellids are the most abundant and dominant groups of benthic foraminifera in epicontinenal seas during Cretaceous period which belong to Rotaliinacean foraminifera. They have shown a wide biogeographical distribution and dispersion in many areas of Tethys. Their evolutionary trend during the Cretaceous time was success. The high concentration of marine sedimentary rocks and the absence of igneous activities in the Kope-Dagh sedimentary basinhave caused it to be considered the most suitable basin for the formation and accumulation of hydrocarbons after the Zagros sedimentary basin. This basin has suitable layers of carbonate rocks and porous sandstones to store hydrocarbon materials, also thick layers of shales in this basin can act as suitable source and cap rocks. In this research some genera and species from this family in Sanganeh and Aitamir Formations at five stratigraphic sections including Marave Tappeh, Takal kuh, Sheykh, Gadvecanlou and Kalat from point of biostratigraphical and paleoecological applications have been investigated. In this study, four biozones including Gavelinella flandrini-Gaudryina cf. praedividens assemblage zone, Berthelina intermedia assemblage zone, Berthelina cenomanica Assemblage Zone, Berthelina intermedia-Osangularia schloenbachi Assemblage Zone have been introduced. Based on the reported genera and species of the Gavellinidae family, it can be stated that the studied formations were deposited in the middle and outer part of the continental shelf to the upper part of the continental slope and in aerobic to semi-aerobic environments. The presence of more planktonic foraminifera than benthic foraminifera in the Aitamir Formation, the depth of the basin increases. Manuscript profile
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  11 - Global record of oceanic anoxic event in the carbonates of the Daryian Formation in the northern High Zagros, Zargran mountain (Gadvan)
  Mazaher Yavari M. Yazdi Hormoz Ghalavand Mohammad Hossein Adabi
  The recording of oceanic anoxic event al record and the time of this event in the shallow carbonates of the Dariyan Formation in Zargran mountain (Gadvan) section in the east of Shiraz, was studied based on carbon and oxygen isotopes, microfacies and fossil data. More

  The recording of oceanic anoxic event al record and the time of this event in the shallow carbonates of the Dariyan Formation in Zargran mountain (Gadvan) section in the east of Shiraz, was studied based on carbon and oxygen isotopes, microfacies and fossil data. In this section, thickness of the Dariyan Formation is 287 m and 191 samples were taken. Based on field data, the sedimentary sequence of this formation, , begins at the base with thick-layered to massive gray limestones containing orbitolinas and rudists, and in the upper parts it includes medium to thick-layered gray limestones including abundant benthic foraminifera, such as orbitolinas. In the mentioned section, based on the study of the embryonic cells of orbitolinas, a late Barmian-early Aptian age was determined for the lower part of this unit, which is the beginning of the formation of anoxic oceanic deposits. The carbon isotope curves between the C3 and C6 curves in the carbonates at the base of the Daryian Formation show disturbances. These changes and the appearance of the Lithocodium-Bacinella facies in this part of the formation confirm the existence of an oceanic anoxic event. The oceanic anoxic event indicates warming of the environment and greenhouse conditions, which was accompanied by abundant rudists in this section and can be a confirmation for the weather conditions of this event. Manuscript profile