Sedimentology
Ehsan Zamaniyan; Mohammad Khanehbad; Reza Mossavi-Harami; Asadollah Mahboubi
Abstract
Qadir Member of Nayband Formation in the eastern part of central Iran have a wide outcrop. Investigating the lithofacies and sedimentary environment of Qadir Member of Nayband Formation (Upper Triassic) in east central Iran, Tabas Block, resulted in identifying the coastal plain, deltaic and open marine ...
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Qadir Member of Nayband Formation in the eastern part of central Iran have a wide outcrop. Investigating the lithofacies and sedimentary environment of Qadir Member of Nayband Formation (Upper Triassic) in east central Iran, Tabas Block, resulted in identifying the coastal plain, deltaic and open marine deposits. Based onfield evidences, the facies features and the geometry of beds, this member consists of two lithofacies include carbonate and siliciclastic facies. The siliciclastic facies were identified as having four sandstone facies (medium-grained), including Sr, Sh, Sp, St and three fine-grained lithofacies, including FI, Fm, Fl (Sr) / Sr (FI) and one coal facies (C). Also carbonate facies are calcirudite and calcarenite. Regarding the field, laboratory studies and identifying the lithofacies, the coastal plain, deltaic (including deltaic plain, proximal delta front, distal delta front, and prodelta) and open marine environments were identified for Qadir Member on which it is under the impact of tidal currents.
B Saberzadeh; K Rashidi; M Vahidinia
Abstract
This paper describes systematic of the foraminifera from Howz-e Khan Member of Nayband Formation in 25km south of the type locality which are exposed in northwest of the Dig-e Rostam area about 300km north of Kerman city and is composed of medium to thick bedded fine-grained limestones containing sponges, ...
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This paper describes systematic of the foraminifera from Howz-e Khan Member of Nayband Formation in 25km south of the type locality which are exposed in northwest of the Dig-e Rostam area about 300km north of Kerman city and is composed of medium to thick bedded fine-grained limestones containing sponges, dasycladales algae, bivalves, corals and partly abundant upper Triassic foraminifera ofNorian-Rhaetian ages which are mainly of aulotortid types. The following foraminifera taxa are described: Auloconuspermodiscoides, Aulotortus friedli, Aulotortus tenuis, Aulotortus tumidus, Aulotortus sinuosus, Duotaxis birmanica, Tetrataxis inflata, Agathammina austroalpina, Miliolipora cuvillieri, Planiinvoluta sp., Ophthalmidium leischneri, Ophthalmidium exiguum, Glomospirella sp., Trochammina alpina, Diplotremina astrofimbriata, Diplotremina subangulata, Duostomina sp., Nodosaria sp1., Nodosaria sp2., Pseudonodosaria sp., Austrocolomia sp., Sigmoilina schaeferae, Reophax tauricus. In this paper relation of foraminifera with reefs and carbonate layerthat are generally typical of low energy, bay or lagoon-type, on shallow carbonate ramps and reef facieshas been studied.
K Rashidi; B Saberzadeh
Abstract
The Upper Triassic sediments in the Central Iran are known as Nayband Formation. They are a set of carbonatic and detritic sediments that can be divided into several members. The carbonatic Bidestan and Howz-e Khan members contain a diverse fauna and flora. In order to study and identify the taxonomic ...
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The Upper Triassic sediments in the Central Iran are known as Nayband Formation. They are a set of carbonatic and detritic sediments that can be divided into several members. The carbonatic Bidestan and Howz-e Khan members contain a diverse fauna and flora. In order to study and identify the taxonomic inventory of the Howz-e Khan member, two profiles were studied in the Naybandan area. The first one is located in southwest of Dig-e Rostam and the second one in southwest of the type locality, which were both sampled systematically. Moreover, unsystematic samples were taken from different parts of the area, which led to the recognition of various algae, foraminifera and sponges. This paper introduces the following sphinctozoan sponges: Nevadathalamia variabilis, Amblysiphonella sp., Discosiphonella sp., Kashanella irregularis, Paradeningeria alpina, Tabasia maxima, Tabasia media, and Tabasia minima.Thelithological and sedimentary structures as well as the microfacies indicate that the Howz-e Khan member has been formed in a shallow marine, near the coastal environment. These circumstances provided perfect conditions for patch-reef-forming organisms (here: sphinctozoan sponges) in the carbonates of the Howz-e Khan member.
Z Kalantarzadeh; M.H Adabi; H Rahimpour Bonab
Abstract
After Early Cimmerian orogenic stage, due to marine transgression, the Nayband Formation Norian_Rethian (Upper Triassic) in age deposited in the Central Iran Zone. Because of transforming of aragonite and high Mg calcite into low Mg calcite during diagenesis, recognition of original carbonate ...
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After Early Cimmerian orogenic stage, due to marine transgression, the Nayband Formation Norian_Rethian (Upper Triassic) in age deposited in the Central Iran Zone. Because of transforming of aragonite and high Mg calcite into low Mg calcite during diagenesis, recognition of original carbonate mineralogy based on petrographic studies is difficult. In this research, original carbonate mineralogy and type of carbonates (tropical, temperate and polar) of the Nayband Formation in Darbidkhoon, Tarz, Gitry and Kuhbanan stratigraghic sections have been studied using geochemical evidences. The trace elements (Na, Sr, Fe, Mn) and isotopes (and) data of the Nayband Formation carbonates is located inside or close to the aragonitic tropical Fahlian Formation (Lower Cretaceous), the Ilam Formation (Upper Cretaceous), the Kangane Formation (Lower Triassic) and the Mozduran Formation (Upper Jurassic) limestones, because of aragonitic original carbonate mineralogy. The results of elemental and isotopic analysis correlate with the petrographic evidences and paleogeographic map of the Upper Triassic.
