Economic Geology
Leila Jaberansari; habibollah Torshizian; Nader Kohansal Ghadimvand; Mohsen Pourkermani
Abstract
The current study was conducted on sedimentary units of the 1:100000 sheet of Jam and Sorkheh in Semnan Province, northeast of Iran. Because of its special geochemical properties, lithium can be concentrated in sedimentary rocks with clay minerals. Samples were collected from stream sediments and lithogeochemical ...
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The current study was conducted on sedimentary units of the 1:100000 sheet of Jam and Sorkheh in Semnan Province, northeast of Iran. Because of its special geochemical properties, lithium can be concentrated in sedimentary rocks with clay minerals. Samples were collected from stream sediments and lithogeochemical in three steps and were processed using Concentration-Number fractal modeling. Concentration-Number fractal modeling is a suitable geochemical exploration method to separate anomaly from the background. It was utilized to identify anomalous areas for lithum and the results were presented in the form of maps. As a result, The Gharavol kooh area of Biabanak in central part of sheet of Sorkheh. According to the lithology of the area, which contains marl and clay minerals (Illite and Cholorit), It was main anomaly between the two sheets. This area should be further investigated in Detailed exploration studies.
Sedimentology
keyvan ahzan; Nader Kohansal Ghadimvand; Seyed Mohsen Aleali; Davood Jahani
Abstract
The Jahrum Formation (Paleocene-Mid Eocene) is one of the most important reservoir units in the Zagros basin and the Persian Gulf. The thickness of this formation in Binaloud oil field in Persian Gulf, which mainly consists of limestones and Dolomites, is about 660 meters. In this research, depositional ...
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The Jahrum Formation (Paleocene-Mid Eocene) is one of the most important reservoir units in the Zagros basin and the Persian Gulf. The thickness of this formation in Binaloud oil field in Persian Gulf, which mainly consists of limestones and Dolomites, is about 660 meters. In this research, depositional environment, sequence stratigraphy and effective diagenesis processes on Reservoir quality of the Jahrum Formation were investigated in Binaloud oil field. The Jahrum succession, which consists of crystalline limestones and dolomites, is overlain by the Asmari Formation and is underlian by the Tarbur Formation unconformably. According to study of cutting samples, eleven microfacies that were deposited in four facies belts, have determined . The most important diagenetic process that was observed in this formation as follows: bioturbation, cementation, dolomitization, dissolution, porosity generation and fracture systems wich is worthy to mation bioturbation and anhydrite cement causes the reduce of reservoir quality and dolomitization , dissolution and secondary porosity causes the reservoir quality. improvement most of facies jahrum formation are mud supported and have very low primary porosity. According to sequence stratigraphy studies, a third order sedimentary sequence with type SB1 boundary was identified in Jahrum subsurface succession.
F. Shirezade Esfahani; A. Bayet-Goll; N. Kohansal Ghadimvand; A. Kangazian; A. Akbari Mohammadi; M. Sadri
Abstract
The carbonate successions (Tournaisian-Visean) exposed in the Tang-e-Darchaleh and Banarizeh sections from Sanandaj-Sirjan Zone (SSZ), Iran, have been used to generate a facies model. From the analysis of facies and their associations, four depositional zones are recognized on the Tournaisian-Visean ...
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The carbonate successions (Tournaisian-Visean) exposed in the Tang-e-Darchaleh and Banarizeh sections from Sanandaj-Sirjan Zone (SSZ), Iran, have been used to generate a facies model. From the analysis of facies and their associations, four depositional zones are recognized on the Tournaisian-Visean ramp: basinal environments, outer ramp (FA1 and FA2; deep subtidal associations), mid ramp (FA3, FA4 and FA6; shallow subtidal to lower intetidal associations), and inner ramp (FA5; shoal). The gradual transitions between facies and facies associations, as well as the depositional profile of the shelf transect indicate a low gradient ramp. The observed sedimentary features in the facies associations portray a transgressive, proximal-to-distal, wave-dominated combined flow marine ramp sequence, as recorded in stratigraphic changes in character of storm bed sequences and the spatial arrangement of types of storm bed along the depth related environmental gradients. This study suggests that during the Lower Carboniferous, a broad shelfal platform covered the southern margin of the Palaeotethys, which was characterized by dominantly shallow carbonate ramp.
H. Hoseini; N. Kohansal Ghadimvad; M. Zamani Pedram; M. R. Majidifard; A. R. Shahidi
Abstract
Accumulation of Shemshak group lithofacies have been started during Early-Cimmerian orogeny from middle of Late-Triassic and ended with Middle- Cimmerian discontinuity dating Millde-Jurrasic. So the mostly Siliciclastic and occasionally Marin lithostratigraphic unite has evidences of two major tectonic ...
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Accumulation of Shemshak group lithofacies have been started during Early-Cimmerian orogeny from middle of Late-Triassic and ended with Middle- Cimmerian discontinuity dating Millde-Jurrasic. So the mostly Siliciclastic and occasionally Marin lithostratigraphic unite has evidences of two major tectonic events as orogenic activity at lower and upper border of sequence. Therefor the lower contact of Shemshak group is composed of Middle-Triassic platform carbonates known as Elika formation which distinguished with Plaeokarsts including bauxit and laterit horizons and the upper contact with parallel unconformity with Delichay formation fossiliferous marls and carbonates of Bajocian stage (Middle Jurrasic). Results of deposition environment and facies studies have shown that the mentioned siliciclastic group (Shemshak) composed of three major facies, 22 subfacies and have been deposited in three different environments including Fluvial (Terrestrial), mid-tidal and shallow marine environments. The vertical changes of facies have declared that the sequence has formed due to erosion of Early-Cimmerian uplands and have experienced progess of shallow marine. The existing shallow marine sediments in the end of Shemshak group states that, in comparison with surrounding area , clastic sediments of end of Shemshak cycle, because of erosional cycles of Middle-Cimmerian orogeny, befor deposition of Delichay marine formation, have been eroded.
N Kohansal-Ghadimvand; SH Gholipouri; M.R Majidifard
Abstract
The early carboniferous Mobarak Formation was studied in southern flank of Ayenehvarzan–Dalichai anticline, in Aru and Seyedabad sections, east of Tehran. The aim of this study is to determine microfacies, interpretation of depositional environments and sequence stratigraphy of the Mobarak Formation. ...
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The early carboniferous Mobarak Formation was studied in southern flank of Ayenehvarzan–Dalichai anticline, in Aru and Seyedabad sections, east of Tehran. The aim of this study is to determine microfacies, interpretation of depositional environments and sequence stratigraphy of the Mobarak Formation. In this study, the thickness of Mobarak Formation in Aru and Seyedabad sections varies from 133 to 65 meters and consists of limestone with intercalations of shale and marl. According to lithological characteristics, the Mobarak Formation subdivided into several rock units. The Mobarak Formation is disconformably overlain by Jirud Formation and underlain by Dorod Formation. Ten microfacies have been recognized on the basis of depositional remarks and petrographic analysis. These carbonate facies belong to 4 major sub-environments including beach/tidal flat, lagoon, barrier/sand shoal and open marine. These facies deposited in a homoclinal carbonate ramp and include two sedimentary sequences.
F Shirezadeh Esfahani; N Kohansal Ghadimvand; A Kangazian; S.H Hejazi; V Hairapetian
Abstract
The Vazhnan Formation in the Shahreza-Abadeh belt, apparently extending from latest Carboniferous to Asselian, consists of conglomerate, limestone, sandstone and shale, which is correlative to the Dorud Formation of the Alborz Mountains and the Zaladou Formation of Central Iran. This work is presenting ...
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The Vazhnan Formation in the Shahreza-Abadeh belt, apparently extending from latest Carboniferous to Asselian, consists of conglomerate, limestone, sandstone and shale, which is correlative to the Dorud Formation of the Alborz Mountains and the Zaladou Formation of Central Iran. This work is presenting some results on revision of the lithostratigraphy of the Vazhnan Formation in the Tang-e-Darchaleh section (northeast of the Shahreza town). Introduction of this interval in the Banarizeh section (north of the Abadeh town) and correlation of the Vazhnan Formation in the sections understudied are other purposes. Based on the results of this study, Vazhnan Formation in the Tang-e-Darchaleh (as the type section) and Banarizeh (as the reference section) section is distinguished with the distinct eroded surface at the base and rests disconformably on the sandstones of Late Carboniferous, corresponding to the Sardar Formation. The upper part of this interval is disconformably overlain by the Surmaq Formation (late Early–Middle Permian) in the Banarizeh section. Field investigations revealed that the contact between the Vazhnan and Surmaq Formations in the Tang-e-Darchaleh section is faulted. The vertical and lateral changes of the lithofacies in the Vazhnan Formation indicate the depositional system which is evolved from a distal into a homoclinal ramp setting.
F Chegeni; D Baghebani; S.H Vaziri; T Mohtat; N Kohansal Ghadimvand
Abstract
For the purpose of biozonation of the Pabdeh Formation (Middle-Upper Eocene) based on planktonic foraminifera, a stratigraphic section in the southern slope of the Mishan Mountain and another in the Eshgar Mountain were studied. The thickness of these sections is 162.5 and 150 meters, respectively. The ...
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For the purpose of biozonation of the Pabdeh Formation (Middle-Upper Eocene) based on planktonic foraminifera, a stratigraphic section in the southern slope of the Mishan Mountain and another in the Eshgar Mountain were studied. The thickness of these sections is 162.5 and 150 meters, respectively. The Pabdeh Formation in the southern slope of the Mishan Mountain consists of marl, marly limestone, shale and limestone, and in the Eshgar Mountain includes alternating cream limestone and thin-bedded marl. In this study, most of the identified microfauna are Planktonic foraminifera. Identified Planktonic and benthic foraminifers in the southern slope of the Mishan Mountain include 18 genera and 8 species, and in the Eshgar Mountain include 21 genera and 10 species. Also four biozones are introduced of which one belongs to the Mishan Mountain and three belong to the Eshgar Mountain as follow: Hantkenina nuttalli Range Zone; Hantkenina nuttalli Turborotalia cerro-azulensis Interval Zone; Turborotalia cerro-azulensis Range Zone; Turborotalia cerro-azulensis/ Hantkenina sp. Assemblage Zone.
N Kohansal-Ghadimvand; Sh Gholipouri; P Ghazanfari; R Mahari
Abstract
The aim of this study is to determine microfacies and diagenetic processes of the Mobarak Formation with the age of early Carboniferous in Valiabad section, at Karaj-Chalus road. The thickness of the formation at this section is 339 m and consists of limestone with intercalations of shale and marl. ...
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The aim of this study is to determine microfacies and diagenetic processes of the Mobarak Formation with the age of early Carboniferous in Valiabad section, at Karaj-Chalus road. The thickness of the formation at this section is 339 m and consists of limestone with intercalations of shale and marl. According to lithological characteristics, the MobarakFormationis subdivided into 8 rock units and is disconformably overlain by the Lalun Formation and underlain by Dozdeband Formation. Thirteen microfacies have been recognized on the basis of depositional texture and petrographic analysis. These carbonate facies belong to four major sub- environments including beach/tidal flat, lagoon, barrier/sand shoal and open marine. The formation deposited in a homoclinal carbonate ramp.
