Stratigraphy and Palaeontology
Nasrollah Abbassi; Safoora Shakeri; Javad Rabbani
Abstract
Numerous Proboscidean footprints have been discovered in the outcrop (135 m) of lower rock unit of the Upper Red Formation (Middle-Late Miocene) in the north Avaj (Qazvin province), central Iran. These footprints are preserved as circular concave epi-relief in the upper bedding planes with smooth or ...
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Numerous Proboscidean footprints have been discovered in the outcrop (135 m) of lower rock unit of the Upper Red Formation (Middle-Late Miocene) in the north Avaj (Qazvin province), central Iran. These footprints are preserved as circular concave epi-relief in the upper bedding planes with smooth or levee rims or with sediment accumulation in the front of the footprints. Five digit imprints present in some of the footprints. The frequency of footprints is considerable the most of the upper surface of layers which was resulted by movement of proboscis herds. Ichnotaxonomically these footprints identified as Proboscipedaen igmatica. The footprints are classified as two sizes as small (15 cm) and large (25 cm) categories, and based on the geometric relationships, the height of shoulder was estimated as 140-170 cm for adult and 76-106 cm immature individuals. According to reports of Miocene Proboscidean body fossils from Iran, and based on the distributions of the Proboscidean in this time, it seems that the Choerolophodon (Gomphotheriidae) is candidate as track-maker of the Avaj footprints. Among the Proboscidean footprints, there are crocodile and fish swimming imprints which were left in the shallow pools.
Stratigraphy and Palaeontology
Abdolvahab Kazemi; Nasrollah Abbassi
Abstract
Agha Jari Formation (Miocene-Pliocene, 788 m) comprises alternations of sandstone, siltstone, and marl in red to brown color layers in the east Gotvand, north Khuzestan province, southwest Iran. Numerous vertebrate footprints have been found in the middle part of the Formation, which includes footprints ...
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Agha Jari Formation (Miocene-Pliocene, 788 m) comprises alternations of sandstone, siltstone, and marl in red to brown color layers in the east Gotvand, north Khuzestan province, southwest Iran. Numerous vertebrate footprints have been found in the middle part of the Formation, which includes footprints of wetland small bird (Aviadactyla media, Gruipeda dominguensis), artiodactyls (Lamaichnum alfi, Lamaichnum isp., Pecoripeda satyri, Pecoripeda isp.), canids (Canipeda isp.) and large reptiles (Hatcherichnus sanjuanensis). Frequency of artiodactyl imprints are more than the other footprints. These footprints proof the living of camels and crocodiles in the Zagros basin for the first time. The ichnotaxa diversity of the footprints in the studied section is more than the other reports of Agha Jari Formation in Iran and its stratigraphic equivalent in the adjacent countries.
Stratigraphy and Palaeontology
Nasrollah Abbassi; Mohammad Vahidinia; Saeid Tavana; Pooria Vaeznia
Abstract
Numerous vertebrate footprints have been found in the dislocated sandstone slabs in the Mashhad city, northeast Iran. Neogene sediments of Chenaran township are supposed to be provenance of the studied slabs. Identified footprints includes artiodactyl tracks as ichnotaxa Bifidipesvelox, Lamaichnum guanicoe, ...
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Numerous vertebrate footprints have been found in the dislocated sandstone slabs in the Mashhad city, northeast Iran. Neogene sediments of Chenaran township are supposed to be provenance of the studied slabs. Identified footprints includes artiodactyl tracks as ichnotaxa Bifidipesvelox, Lamaichnum guanicoe, Pecoripeda amalphaea, Pecoripeda isp., Carnivore tracks as Canipeda isp., and Felipeda isp., and bird tracks as Avidactyla isp., Avipeda gryponyx, Fuscinapeda texana. Among studied slabs, bird tracks are abundant. This is the first report of Cenozoic vertebrate tracks from the Kopeh Dagh geological zone. Discovery of Lamaichnum guanicoe shows Camelidae distribution in Iranian Plateau is as old as Neogene, and it is the first report of Camelidae sign from Iran. Presence of diverse footprints from Kopeh Dagh shows attenable biodiversity in the region of Iran.
Stratigraphy and Palaeontology
Nasrollah Abbassi; Reza Aharipour
Abstract
Mila Formation includes five members in the Tuyeh-Darvar section, west Damghan. Fifth Member of formation comprises alternations of calcareous shale, limestone and green shales. Trace fossils of this member includes Cruziana problematica, Gordia isp., Helminthopsis abeli, Helminthopsis tenuis, Palaeophycus ...
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Mila Formation includes five members in the Tuyeh-Darvar section, west Damghan. Fifth Member of formation comprises alternations of calcareous shale, limestone and green shales. Trace fossils of this member includes Cruziana problematica, Gordia isp., Helminthopsis abeli, Helminthopsis tenuis, Palaeophycus striatus, Planolites beverleyensis, Psammichnites gigas, Scolicia strozzii and Treptichnus pedum. Circulichnis montanus abundant in the upper most layers of the fifth Member and is circular cylindrical ring in shape. Circulichnis is a fodinichnion, that produced by progressive and plasticity behaviors of annelids. It seems that these trace fossils are belong to the mid parts of the turbidite rhythmic sequences and formed in the turbidity conditions of the sedimentary environment.
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
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
Zahra Hosseini Asgarabadi; Nasrollah Abbassi; Hassan Mohseni; Saeed Khodabakhsh
Abstract
The Pabdeh Formation (Paleocene to Oligocene in age) comprises alternation of marl and limestone with the Purple Shale at the base is well exposed on the flanks of the Kabir-Kuh. Thalassinoides, Rhizocorallium, Planolites, Chondrites, cf. Rosselia, Spirophyton and Zoophycos were found in the limestone ...
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The Pabdeh Formation (Paleocene to Oligocene in age) comprises alternation of marl and limestone with the Purple Shale at the base is well exposed on the flanks of the Kabir-Kuh. Thalassinoides, Rhizocorallium, Planolites, Chondrites, cf. Rosselia, Spirophyton and Zoophycos were found in the limestone beds, among which trace fossils of Zoophycos group (Spirophyton and Zoophycos) are the most abundant. Structural variations of trace fossils of Zoophycos group were utiliized for recognition of five morphotypes including Rhizocorallium-shaped, branched Zoophycos, Spirophyton, short and fan-shaped lobate Zoophycos and long lobate Zoophycos morphotypes. Occurrence of these morphotypes in the studied sections implies an evolutionary trend, i.e. Rhizocorallium-shaped and branched Zoophycos morphotypes are developed in the lower parts of studied sections, whereas Spirophyton morphotype, is arranged in the mid-part of the Pabdeh Formation. Finally, short and fan-shaped lobate and long lobate Zoophycos morphotypes are abundant in the upper part of the formation. Seemingly, these morphotypes variation were adopted with switch of stable and calm water to unstable and relatively high energy environments.
M Hadi; H Mosaddegh; N Abbassi
Abstract
Carbonate successionsof the Ziarat Formation with introduce the Baghdareh and Gheynarjehsections in the Soltanieh Mountains(southern Zanjan) are rare locality in the western Alborzzone,which are contains of great abundance oflarge benthic foraminifera (LBF), particularly species of Alveolina. In fact, ...
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Carbonate successionsof the Ziarat Formation with introduce the Baghdareh and Gheynarjehsections in the Soltanieh Mountains(southern Zanjan) are rare locality in the western Alborzzone,which are contains of great abundance oflarge benthic foraminifera (LBF), particularly species of Alveolina. In fact, from this succession described some of Alveolinaspecies and their comparative stratigraphic distribution with the Alveolina species in the Tethyanbasinwhich is represent close affinitieswith coeval Alveolinaassemblages described in diVerent studies from this province. Also, this correlation shows Ilerdian-Cusianstages of study area that characterized by A. ellipsoidalis, A. laxa, A. tumida, A.cemali, A.aragonensis, A. pisiformis,A.rotundata, A.subpyrenaica, A. cf. canavari, A. canavari, A.ex gr. cremae species.
N Abbassi; M Parvanehnezhad Shirazi; M.A Hosseinzadeh
Abstract
Albian–Cenomanian siliciclastic-carbonate sediments of northwest Rayen in south Kerman, southeast Iran (526 m) are classifiable to three informal units. Unit one includes conglomerates, sandstones and siltstones with limestone and marl intercalations. Unit two is composed of Orbitolina bearing ...
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Albian–Cenomanian siliciclastic-carbonate sediments of northwest Rayen in south Kerman, southeast Iran (526 m) are classifiable to three informal units. Unit one includes conglomerates, sandstones and siltstones with limestone and marl intercalations. Unit two is composed of Orbitolina bearing limestones with rudists, belemnoid and ammonite bioclasts. Alternations of pelagic limestones and sandstones formed the third unit. Assemblage of continental to marine trace fossils have been found in the first and third units of the studied section, that include Koilosoma isp., Ophiomorpha isp., Palaeophycus isp., Planolites isp., Skolithos isp., Taenidium isp., and Thalassinoides suevicus. These trace fossils belongs to Scoyenia, Skolithos and Cruziana ichnofacies. Abundant Thalassinoides-Phycodes compound trace fossil, however have been found in the third unit. Box-worked Thalassinoides burrow system ends to multi- branched Phycodes borrows. This compound trace fossil is interpreted as feeding-domicile biogenic structure, so that Thalassinoides domichnium ends to Phycodes excavated feeding burrows. Compound Thalassinoides-Phycodes trace fossil extended in the deeper parts of offshore shelf sediments in the studied section. Based on ichnological data, it seems that Albian–Cenomanian sediments of northwest Rayen deposited in a deepening upward sequence.
A Bayat Gol; N Abbassi
Abstract
A detailed ichnological study on the Geirud Formation (Late Devonian-Early Carboniferous) from the Zaygon area, central Alborz shows a diverse trace fossils, which include 14 ichnogenera represented by 23 ichnospecies. These trace fossils contains various ethological patterns, such as domichnia, fodinichnia, ...
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A detailed ichnological study on the Geirud Formation (Late Devonian-Early Carboniferous) from the Zaygon area, central Alborz shows a diverse trace fossils, which include 14 ichnogenera represented by 23 ichnospecies. These trace fossils contains various ethological patterns, such as domichnia, fodinichnia, grazing, equilibrichnia, and fugichnia. These trace fossils are: Arenicolites, Asterosoma, Chondrites intricate, Chondrites targionii, Diplocraterion parallelum, Arenicolites isp., Asterosoma isp., Chondrites intricate, Chondrites targionii, Chondrites isp., Diplocraterion parallelum, Helminthoidichnites isp., Helminthopsis abeli, Helminthopsis isp., Palaeophycus heberti,Palaeophycus tubularis, Planolites beverleyensis, Planolites isp., Phycodes cf. palmatus, Rhizocorallium jenense, Rhizocorallium irregular, Rosselia soccialis, Taenidium serpentinum, Taenidium satanassi, Talassinoides horizntalis, Thalassinoides suevicus, Thalassinoides paradoxicus, Zoophycos isp. Studied beds consist by alternations of laminated mudstones and siltstones, and thick- to medium-bedded sandstones with wavy lamination. Hummocky, trough and low angle to planar cross-bedding are common in layers. It seems that these beds were deposited in the delta to open marine environments. Determined ichno-assemblage represents characteristic of a moderately shallow-marine environment, which effected occasionally by high-energy conditions. A trace fossil assemblage has been examined from the uppermost dark-colored shale layers of the Geirud Formation in the Devonian/Carboniferous (D-Ca) boundary. This assemblage include Chondrites targionii, Zoophycos isp., which involved by Hangenberg event.
A. Bayat Gol; N. Abbassi; A. Mahboubi; R. Moussavi-Harami; H. Amin Rasouli
Abstract
Some of Paleozoic sediments from Alborz and Central Iran subzones from Mid-Iran zone evaluated for distinction of Palaeophycus and Planolites ichnofossils. These sediments include Shale Member of Lalun Formation, Shirgesht Formation, member 5 of Mila Formation and Geiroud Formation. A diverse ichnofauna ...
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Some of Paleozoic sediments from Alborz and Central Iran subzones from Mid-Iran zone evaluated for distinction of Palaeophycus and Planolites ichnofossils. These sediments include Shale Member of Lalun Formation, Shirgesht Formation, member 5 of Mila Formation and Geiroud Formation. A diverse ichnofauna has been found in these Formations, so Planolites and Palaeophycus are abundant between them. Ichnotaxa diagnosis and some determination problems of these ichnogenera was discussed here. Overall characteristics of Palaeophycus suggest dwelling structure made by predator or suspension-feeder and passive sedimentation in the open burrow. Planolites, on the other hand imply active backfilling structure in ephemeral burrows, which constructed by a mobile deposite-feeder. Planolites include unlined burrows with infilled sediments differ texturally from host rock. Whereas Palaeophycus is lined burrow filled by same sediments of surrounding matrix. Accordingly, Palaeophycus assemblage members made by opportunistic communities with r-selected population strategies in physically-controlled and unstable environment, whereas ichnofossils of Planolites assemblage are related to benthic communities with displaying K-selected or climax strategies in the stable environments and rather predictable conditions. Recognized ichnospecies of Planolites are P. montanus, P. annularis, P. terraenovae and P.beverleyensis. and ichnospecies of Palaeophycus include P. heberti, P. tubularis, P. striatus. P. sulcatus and P. alternates.
Nasrollah Abbassi
Abstract
Cretaceous flysch deposits of the Abshar-e Asyab Kharabeh (30 meters) in west of Siah-rud village in the Jolfa area, NW Iran, consist of conglomerate, sandstone, siltstone and mud- or marlstone layers, which mainly belong to A, B, D and E divisions of Bouma sequence. A divers trace fossils preserved ...
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Cretaceous flysch deposits of the Abshar-e Asyab Kharabeh (30 meters) in west of Siah-rud village in the Jolfa area, NW Iran, consist of conglomerate, sandstone, siltstone and mud- or marlstone layers, which mainly belong to A, B, D and E divisions of Bouma sequence. A divers trace fossils preserved on the lower bedding planes of sandstones and siltstones as positive hyporelief, includes: Bergaueria hemispherica, Bergaueria isp., Cochlichnus isp., Granularia isp., Halopoa imbricate, Helminthoida crassa, Helminthopsis abeli, Imponoglyphus torquendus, Neonereites multiserialis, Paleodictyon latum, Paleodictyon cf. majus, Paleodictyon nodosum, Palaeophycus alternatus, Palaeophycus sulcatus, Phycodes templus, Phycodes isp., Planolites annularis, Planolites beverleyensis, Protovirgularia longespicata, Squamodictyon isp., Strobilorhaphe isp., Thalassinoides isp., Taphrhelminthopsis recta, Taphrhelminthopsis convolute, Treptichnus pollardi. These trace fossils are mainly grazing-feeding or feeding traces of Nereites Ichnofacies and classifiable in six rang/frequency, based ichno-assemblages. Obtained trace fossils were produced during post-event calm periods. So, muddy sediments deposited after turbulence currents and traces have been made on these layers, activates of trace makers were developing when accessible feeding materials or dissolved oxygen increased in environment. Base on founded Nereites trace fossils, these sediments deposited in the deep marine abyssal zone environment.
N. Abaasi
N. Abbassi; A. H. Amini
Abstract
The Upper Miocene Upper Red Formation in the Evan-e-Key Section is composed of conglomerates, sandstones, mudstones, and thin lenses of evaporates (gypsum). The formation is dominated by gypsiferous mudstones and characterized by fining-up cycles in this area. The whole ...
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The Upper Miocene Upper Red Formation in the Evan-e-Key Section is composed of conglomerates, sandstones, mudstones, and thin lenses of evaporates (gypsum). The formation is dominated by gypsiferous mudstones and characterized by fining-up cycles in this area. The whole formation occurs as a fining upward megasequence, in which the sandy facies dominate the lower half and muddy facies the upper half. Gypsum layers, up to 10 meters thick, are locally observed in the basal part. The formation has suffered an extensive weathering in the region, as a result of which primary features (e.g. sedimentary structures, trace fossils) are partially obscured. In the sandy units of the middle part of the formation some vertebrate footprints are observed, which are locally deformed due to intensive weathering of the rocks. Two types of Carnivoripedida footprints however, are distinguished and described here, so that well preserved Chelipus isp. is related to Felidae. Depositional environments including alluvial fans with abundant debris flows, gravelly bed load braided systems with wide flood plains and local swamps provided a good opportunity for development of the track makers. The transverse and longitudinal bars within the channels, levees, and over-bank sub-environments were found more suitable for development and preservation of the footprints. Comparing with other sections of the formation (e.g. Qum area), desirable climate was found a major control on development of the vertebrate track maker in the Evan-e-key area.
N. Abbassi; A. Amini
Abstract
The Thalassinoides bearing calcareous sandstone and sandy limestones of Oligocene age unconformably overlay the Eocene volcaniclastic rocks and gradually pass into the lacustrine sediments (Miocene? in age) in the study area. These layers are dominated by Thalassinoides ...
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The Thalassinoides bearing calcareous sandstone and sandy limestones of Oligocene age unconformably overlay the Eocene volcaniclastic rocks and gradually pass into the lacustrine sediments (Miocene? in age) in the study area. These layers are dominated by Thalassinoides suevicus (Rieth 1932) in the Y shaped boxwork cylindrical and bifurcating burrows, which are mainly filled actively by trace maker(s). The bioturbations in the layers are categorized into five ichnofabric classes, which are equal to standard ichnofabric indexes of 1 to 5. Frequency of the ichnofabric classes are 40.37, 15.9, 8.85, 4.97 and 29.9 percents, respectively. Ichnofabric variations of the studied layers are arranged in seven bioturbated upward cycles, which are divided into two groups. The first group shows low ichnofabric fluctuations and a constancy in the bioturbation, where the second group shows high ichnofabrics fluctuations and variability in the bioturbation. Results from the study show that the Thalassinoides in the studied section formed in conditions similar to those of Cruziana and Glossifungites ichnofacies.
