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    • List of Articles مهدی رضا پورسلطانی

      • Open Access Article

        1 - The study of post depositional history in the Chehel Kaman formation, in the eastern regions of Kopet-Dagh, North-East Iran
        Somayeh Erfani Mohammad Javanbakht Mehdireza Poursoltani
        The Chehel Kaman Formation of the upper Paleocene age formed from carbonate and siliciclastic sediments is located, in the Kapeh Dagh Sedimentary Basin. Two sections where considered for the purpose of research into the effective diagenetic processes of this formation. More
        The Chehel Kaman Formation of the upper Paleocene age formed from carbonate and siliciclastic sediments is located, in the Kapeh Dagh Sedimentary Basin. Two sections where considered for the purpose of research into the effective diagenetic processes of this formation. The Cheshmeh Qorban section with a thickness of 270.8m located 140km down the Mashhad – Sarakhs Highway while the Shourlog Section with a thickness of 288.3m is situated 130km down the Mashhad – Mozduran – Sarakhs Highway. 120 samples were taken from these sections and 100 thin cross sections produced from these samples. The carbonate rocks of this formation have been affected by diagenetic processes such as cementation, micritization, neomorphism, dissolution stress and porosity. These processes have taken place at the four marine diagenetic stages of the underground and surface sweet water. All cross sections were investigated using a gypsum bladein order to identify any extant porosity. All changes including type and percentage were plotted for each section. The results of the investigations indicated that in the Cheshmeh Qorban section of the Chehel Kaman Formation the lowest porosity content with a 3% rate of recurrence was related to microporosities while the greatest accumulation of porosity with a 7% recurrence rate in porosity was due to fracture porosity. In the Shourlog section meanwhile the lowest porosity content with a 2% recurrence rate was related to microporosities and the greatest accumulation with a recurrence rate of 6% was due to vuggy porosity. Manuscript profile
      • Open Access Article

        2 - Porosity evolution and diagenetic history of the upper Jurassic Mozduran Formation, eastern Kopet-Dagh Basin, NE Iran
        Mehdi Reza Poursoltani Mahin Hrati Sabzvar
        The Upper Jurassic carbonates of the eastern part of the Kopet-Dagh Basin, with thickness of 470 m, are the major gas-bearing reservoir in NE Iran. The objectives of this study are recognition of diagenetic history and estimation of porosity related to dolomitization. B More
        The Upper Jurassic carbonates of the eastern part of the Kopet-Dagh Basin, with thickness of 470 m, are the major gas-bearing reservoir in NE Iran. The objectives of this study are recognition of diagenetic history and estimation of porosity related to dolomitization. Based on field and laboratory study, four carbonate facies associations have been identified at the Mazdavand outcrop. Most of the carbonate rocks were deposited in an open marine, tidal channel and barrier, lagoon and tidal flat setting. Using petrographic and CL analyses, the main diagenetic processes that affected these rocks are micritization, cementation, compaction, fracturing, dissolution, neomorphism, silicification, and dolomitization. Dissolution of grains and calcite cement generated secondary porosity, whereas compaction and cementation are the primary cause of porosity reduction. The average porosity of core plugs is 15.78% and match well with two-dimensional estimates from thin sections. The more porous samples are either highly fractured or contain interparticle and intercrystalline porosity, within the lower strata that contain more dolostone. Manuscript profile
      • Open Access Article

        3 - Sea-level change and deep sea sequence stratigraphy: A Middle Jurassic siliciclastic strata (Kashafrud Formation), NE Iran
        Mehdi Reza Poursoltani
        The Upper Bajocian- Lower Bathonian succession in the Kopet-Dagh Basin of NE Iran represents fluvio-deltaic to turbidite deposits. The Kashafrud Formation provides an excellent opportunity to study the interplay between deep-water sedimentation and syndepositional tecto More
        The Upper Bajocian- Lower Bathonian succession in the Kopet-Dagh Basin of NE Iran represents fluvio-deltaic to turbidite deposits. The Kashafrud Formation provides an excellent opportunity to study the interplay between deep-water sedimentation and syndepositional tectonic subsidence (or uplift) in the region. The effects of these processes caused sea-level changes, variation in depositional sequences, and formation of different types of sequence boundaries. The Kashafrud Formation is recognized as a super-sequence and is overlain and underlain by type 1 sequence boundaries. Based on sedimentological analysis, twelve lithofacies and three facies associations have been identified in the Kashafrud Formation. The succession is represented by parasequences formed as part of a second order super-sequence, and a fourth order regression. The thickness variations indicate a strong influence of basin-floor topography on the location of depositional successions. High rates of sea-level fall led to the development of a limited number of major incised channels; in contrast the major thick-bedded mudstone indicates high rates of sea-level rise for prolonged periods. The interpreted sea-level curve during deposition of the Kashafrud Formation can be correlated with the world sea-level curve for the Middle Jurassic, with differences mainly related to local structural events in the basin. Tectonism, compaction and rate of deposition were the main factors that controlled the vertical facies transitions in these parasequences. Manuscript profile