Tectonics
Zahra Tavazo; Ebrahim Gholami; Hossien Motamedi; Bahman Soleimany
Abstract
Numerous mechanisms are active during folding in folded-thrust belts, such as the role of salt movement, the role of multiple detachments in sedimentary cover, interference between different phases of deformation, and the role of basement during folding. The performance of these mechanisms plays an important ...
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Numerous mechanisms are active during folding in folded-thrust belts, such as the role of salt movement, the role of multiple detachments in sedimentary cover, interference between different phases of deformation, and the role of basement during folding. The performance of these mechanisms plays an important role in the formation of different structures and geological features in geological units and folds geometry. In this research, such structures have been introduced and studied in Takhteh, Nahreh and Kuh-e-Lar anticlines in the north of Fars Paleo-High during field observations and measurement of geometric features of anticlines such as Aspect ratio, axial distance and half wavelength. These structures mainly include growth strata, geometry of tectonic synchronous strata, structures associated with shallow detachment such as rabbit ear structures, faults that are themselves structures that control the geometry and kinematics of structures, and sulfur springs that related to faults and rheology of exposed formations. The present study shows that the anticlines have an aspect ratio less than ten and are part of the detachment folds in which the detachment horizons have played a role and have a dextral arrangement. The formation of these anticlines occurred at the same time, which will be connected to each other, and these anticlines are associated with basement faults. The location of these anticlines is suitable for the presence of hydrocarbons but the basement fault in the southern flank of Takhteh anticline may affect the reservoir. The presence of water gaps and wind gaps in the region is a sign of uplift and activity of the region.
Tectonics
Nayyer Bayeste Hasti; Hosein Motamedi; Mahmoud Almasian
Abstract
This study has focused on the result of seismic data. The first stage of basin formation is the opening of Neo- Tethys Sea which is Simultaneous with Dashtak, Kangan and Khaneh kat Formation and after that on the early to middle Triassic sediments an unconformity that can be named as an expansion of ...
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This study has focused on the result of seismic data. The first stage of basin formation is the opening of Neo- Tethys Sea which is Simultaneous with Dashtak, Kangan and Khaneh kat Formation and after that on the early to middle Triassic sediments an unconformity that can be named as an expansion of sedimentary basin in the upper Triassic happened. This stage of basin opening caused the formation of big faults and probably basement faults in the area that studying on this faults and their movements is the main goal of this study. The next stage of evolution of basin starts when the basin began to closure and still there is disagreement about the exact time; but the obvious thing is the four compressional events: first, from Cenomanian- Turonian up to Masstrichtian; second, Late Paleocene- Early Eocene; third, Late Oligocene-Miocene and the forth, Miocene up to Quaternary. All events caused to obduction of Ophiolite and sedimentation of Gurpi with partly erosion and Pabdeh with regional erosion, then disappearing formations such as Asmari and Gachsaran and at the end, the late Zagros orogenic phase which is the compression that is continues to this day.
F. Motaki; H. Motamedi; N. Dehbashi
Abstract
Goshtasb anticline is situated in southeast of Shiraz. The dimension of this anticline is about 54 km length and maximum width of 7 km in the level of the Asemari–Jahrum carbonates exposure. The general trend of the structure is NW-SE which swings to an E-W trend in its eastern plunge possibly ...
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Goshtasb anticline is situated in southeast of Shiraz. The dimension of this anticline is about 54 km length and maximum width of 7 km in the level of the Asemari–Jahrum carbonates exposure. The general trend of the structure is NW-SE which swings to an E-W trend in its eastern plunge possibly offsetted by branches of the Sarvestan fault. The northern flank of the anticline is steeply dipping to overturned whereas the southern flanks dips about 25-35, and therefore the anticline shows a distinct asymmetry to northeast in surface. In this research we show that this geometry is a result of activation of intermediate detachment levels in the stratigraphy succession specially Triassic evaporates of the Dashtak Formation, and the surface culminations of this anticline are merged together at depth to form a single structure (the Mozaffari anticline) in the Dehram level below the Dashtak Formation. In this research, an integration of field survey and available subsurface combined with modern structural ideas have been used to study of the geometry of the Dehram horizon. For this purpose, 6 geological cross sections with the total length of 147 km and one 51-km-long longitudinal section have been constructed. Also an underground contour map of the Dehram horizon is produced using structural cross sections. According to this map, the areal and vertical closure of the Goshtasb anticline is 11.5X47 km² and 2000 m, respectively.
