F. Alahverdi Maygooni; M. Mohamadi Vizheh; A.R. Farrokhnia; E. Boostan; H. Nazari
Abstract
Undoubtedly, one of the evidence of tectonic activity in each region is earthquake, which has a major role in casualties and financial losses. The earthquake is usually caused by faults that sometimes extend to the depths of the earth's crust. In cases where no signs or complications of these faults ...
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Undoubtedly, one of the evidence of tectonic activity in each region is earthquake, which has a major role in casualties and financial losses. The earthquake is usually caused by faults that sometimes extend to the depths of the earth's crust. In cases where no signs or complications of these faults are observed on the surface of the earth, it is necessary to get a better understanding of these faults and its sub branches by combining geological knowledge as well as remote sensing and geophysical instruments. The Kazar fault in the study area is a fundamental fault that has been attributed to at least six historical earthquake events. Due to quaternary activities, recognition of this fault is very important in the region. Therefore, geological and geophysical studies were carried out on the historical site of Gohartepeh in Behshahr city to reveal its hidden parts. Specific resistive methods with bipolar bipolar arrangement at 10 and 20 meters intervals are used to provide sections and maps. By examining them and considering the position and depth of the anomalies obtained in the next stages, new profiles and networks were designed. In order to obtain more accurate results, the cesium magneto metric scanning was performed on 4 profiles. Data obtained from field operations and data acquisition as well as final processing of data in specialized software have been incorporated and clearly interpreted from sub-surface structures, especially faults and discontinuities in the study area, which indicate an impressive anomalous adaptation obtained with field evidence.
Tectonics
Golnaz Abbasi; Ali Solgi; Mohsen Pourkermani; Hosein Motamedi; alireza farrokhnia; Keivan Orang
Abstract
We used 2D seismic profiles, field observation and well data to constrain the structural evolution of the Saveh basin during the late-lower Miocene to late Pliocene. During this time period almost 8-9 kilometers of Upper Red Formation (URF) and the Pliocene conglomerates were deposited in the basin depocenter. ...
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We used 2D seismic profiles, field observation and well data to constrain the structural evolution of the Saveh basin during the late-lower Miocene to late Pliocene. During this time period almost 8-9 kilometers of Upper Red Formation (URF) and the Pliocene conglomerates were deposited in the basin depocenter. During the late- lower Miocene (to early- middle Miocene ?), Syn-depositional activity of west-east-northwest-southeast trending high-angle fault zones, with an extensional component, created accommodation space for deposition of lower Upper Red Formation. Since the late- middle Miocene (or late Miocene), initiation of a compressional phase has resulted in regional deformation.The deposition of upper part of the URF and the Pliocene conglomerates was contemporaneous with compressional deformation. During this stage, the middle part of the URF acted as an effective detachment horizon and detachment folds, such as the Saveh and Taraz Naeen anticlines, were formed. The thinning of the Pliocene conglomerates towards the crestal point of these folds indicates late structural growth. According to the top Qom depth map, there are no traps with fault independent closure within the Saveh basin. The top of the Qom Formation is estimated at -4250 m in the Taraz Naeen anticline.