P Rezaee; R Zarezadeh
Abstract
Qeshm is the largest island of the Persian Gulf and is located at the southern end of the folded Zagros zone. The stratigraphic units of the QeshmIsland include the Hormoz series, Mishan formation, Aghajari formation and the Quaternary deposits. The Quaternary calcareous marine terraces are an important ...
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Qeshm is the largest island of the Persian Gulf and is located at the southern end of the folded Zagros zone. The stratigraphic units of the QeshmIsland include the Hormoz series, Mishan formation, Aghajari formation and the Quaternary deposits. The Quaternary calcareous marine terraces are an important part of the deposits and an relief index of sea level changes of the Quaternary period in the QeshmIsland. These terraces overly unconformably the older deposits, specially the Aghajari formation. The field and laboratories studies show that these sediments were developed mostly in different parts of an inner ramp comprising of supra-intra tidal, lagoon, and barrier. Application of the radiocarbonical method in different levels of these terraces revealed a Holocene-Pleistocene age. According to this age, an uplift rate of 0.22 mm/y can be estimated for this island, while the throw rate of the Persian Gulf level during the Quaternary is -0.125 mm/y.
H. R. Javadi; M. R. Ghassemi; M. Shahpasandzadeh; M. Estrabi Ashtiani
Abstract
Dorouneh Fault System (DFS) is located along northern border of Central Iran microplate. Its mechanism is left-lateral strike-slip with reverse dip-slip component. Considering curve geometry of DFS, it is divided into three major parts: eastern, middle and western. Middle part extends from Torbat-e-Heidarieh ...
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Dorouneh Fault System (DFS) is located along northern border of Central Iran microplate. Its mechanism is left-lateral strike-slip with reverse dip-slip component. Considering curve geometry of DFS, it is divided into three major parts: eastern, middle and western. Middle part extends from Torbat-e-Heidarieh city in the east to Anabad village in the west. It passes through Quaternary loose alluviums. DFS is composed of different segments in this part. Bend and right-lateral en echelon geometry at surface and left-lateral strike-slip movement of DFS cause local transpression that is observed as young folding. Fold core is composed of Neogene marl, sandstone and siltstone and fold limbs are composed of Pleistocene loose gravely sediments. Mentioned folds were formed by two different mechanisms: first, Anticlines that formed in right-step bends of DFS and second, pressure ridges that are limited among parallel branches and overlaps of DFS. Estimation of relative uplift rate along mentioned folds indicates that more earthquakes occur in regions with higher uplift rate.