Writers : Aghai,Ali;Supervisor;M,Ghasemi.H,Safaee
Refference : M.Sc.Thesis- Ferdowsi University, Mashhad
Publishing Year : 1383

Abstract :

Mozduran Formation is one of the hydrocarbon reservoirs in Kpet-Dagh basin in northeast Iran. This formation has an extensive exposure and variable litho logy in the Kopet-Dagh Basin. In this study, 4 sections in north Shurab, north and south part of Kal-e-Shah Mohammad and Shurab village has been measured. The thicknesses of this formation in these sections are 408.5, 195.5, 140.5 and 88.5m, respectively. The boundries of Mozduran Formation with the lower (Kashafrud) and upper (Shurijeh) units are erosional.
Based on lithostratigraphic evidence, Mozduran Formation has been divided into different portions.
This formation is composed of oolithic and bioclastic limestones with shale and sandstone beds in north Shurab, bioclastic an oolithic limestones in north of Kal-e-Shah Mohammad, while south of Kal-e-Shah Mohammad it is composed of sandstone with interbeds of shale and lime mudstone.
Based on petrographic studies of 200 samples, 4 carbonate facies, one evaporite facies and two siliciclastic facies (sandstone and shale) have been recognized. Facies A consists of (echinoderm brachiopod bioclast packstone and brachiopod bioclast grainstone). Facies B consists of sandy bioclast grainstone bearing ooid, sandy bioclast ooid grainstone, ooid pelecypod bioclast grainstone, intraclast grainstone, intraclast ooid grainstone, sandy pelecypod ooid grainstone and sandy ooid grainstone. Facies C is composed of ooid packstone, sandy ooid bioclast packstone, ostracod lime mudstone and pelloidal lime packstone. Fades D consist of dolomudstone and lime mudstone).
These carbonate facies are deposited in homocline ramp in Open marine, barrier and lagoon environments, repectively. Facies and siliciclastics are also deposited in tidal flat environments. Evaporate facies in Mozduran Formation based on thickness and wide exposurs specially in North Shurab and North Kal-e-Shah Mohammad may have formed in sauna environment.
The most important diagenetic processes operated in carbonate rocks consist of cementation, micritization, compaction, neomorphism, dolomitization and in sandstones are cementation, compaction, dolomitization, dissolution and hematitization. Theses processes affected mozduran formation in three diagenetic environments including marine, meteoric and burial and three stages including eogene, mezogene and telogene. Sequence stratigraphy study of Mozduran formation led to identification of 2 depositional sequences.
Paleogeographic reconstraction of the study area is indicated that these rocks were deposited in six stages during the Upper Jurassic in the Eastern of Kopet-Dagh basin.

Subject List : sedimentation history