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The Siruyeh landslide occurred at the eastern side of the Siruyeh valley, 22 km west of Semirom city, south of Esfahān on
25th March, 2005 with large dimensions (2,400 m long, 450 m wide with total area of 1 km2). The sliding mass blocked the Siruyeh River making a 35-m-high natural dam and 6-acre lake 570,000 m3 in volume that poses a potential threat for the area. The landslide occurred in soil and intensely weathered marls of the
Tarbur and Kashkan Formations (upper Cretaceous–Paleocene age). The overall comparison and interpretation of the gathered
evidence from satellite images, field trips, and laboratory tests show that the most important factors involved in triggering
the Siruyeh landslide in order of importance are heavy precipitation and snow melt and intense concentration of faults and
fractures as well as weathered and weak lithology. 相似文献
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Abbas Babaahmadi Mohammad MohajjelAbbas Eftekhari Ali Reza Davoudian 《Journal of Asian Earth Sciences》2012,43(1):77-88
The NW-SE trending Sanandaj-Sirjan Zone (SSZ) is the internal part of the Zagros continental collision zone, which mainly consists of metamorphic rocks deformed in a dextral transpressional zone. This dextral transpression is attributed to brittle deformation related to late Cenozoic Arabia-Eurasia oblique continental collision. Major NW-trending faults, including the Dalan, Garmdareh, Yasechah, Sheida, and Ben faults, are reverse faults with a dextral strike-slip component. These faults were displaced by NW-trending synthetic and NE-trending antithetic faults. There are also E-trending thrusts and N-trending normal faults developing in directions that are, respectively, almost normal and parallel to the major shortening direction. The NW-trending Ben, Yasechah, and Sheida faults are NE-dipping faults, and the Dalan and Garmdareh faults are SW-dipping faults. These faults indicate the presence of a transpressive flower structure zone that probably led to the exhumation of Jurassic high-grade metamorphic rocks, such as eclogite, in the central part of the study area. 相似文献
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Babaahmadi Abbas Sliwa Renate Esterle Joan Rosenbaum Gideon 《International Journal of Earth Sciences》2018,107(5):1895-1910
International Journal of Earth Sciences - The Duaringa Basin in eastern Australia is a Late Cretaceous?–early Cenozoic sedimentary basin that developed simultaneously with the opening of the... 相似文献
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The Texas and Coffs Harbour oroclines are defined by a Z-shaped curvature in the southern New England Orogen (eastern Australia), but the geometry and kinematics of faults around these oroclines, as well as their possible role during oroclinal bending, have hitherto not been understood. Using aeromagnetic and open file seismic data, as well as field observations, the pattern, geometry and kinematics of fault systems, have been investigated. Fault traces with a strike-slip component are oriented parallel to the curved magnetic and structural fabrics of the Texas and Coffs Harbour oroclines. Our observations show evidence for sinistral or sinistral-reverse, dextral (or dextral-reverse) and normal kinematics along NW-striking faults. The dominant kinematics along NNE- and NE-striking faults is dextral or dextral-reverse. The timing of faulting is not well constrained, but the ubiquitous recognition of orocline-parallel faults may suggest that a flexural slip mechanism operated during oroclinal bending in the early–middle Permian (ca 299–265 Ma). Our observations indicate that many of the orocline-parallel faults, with strike-slip separation, were reactivated during the Mesozoic and Cenozoic, as indicated by the recognition of displaced Triassic granitoids, Mesozoic sedimentary rocks and Cenozoic basalts. 相似文献
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Triassic to Lower Cretaceous continental sedimentary basins occur in eastern Australia, but the tectonic and structural evolution of these basins is not fully understood. Using gridded aeromagnetic data, seismic reflection data and field observations, we conducted a structural analysis aimed at characterising major faults and deformation style in these sedimentary basins. Our results show evidence for two alternating episodes of rifting during the Triassic. An earlier episode of rifting, which took place in the Early Triassic to early Late Triassic, is inferred based on synsedimentary normal faults in the Nymboida Coal Measures and the boundary West Ipswich Fault System in the Esk Trough. This phase of rifting was followed by a contractional event that resulted in tilting, folding, and thrust faulting. Evidence of synsedimentary normal faults and bimodal volcanism indicates that another rifting phase occurred during the Late Triassic and resulted in the development of the Ipswich Basin. From the latest Late Triassic to the Early Cretaceous, the accumulation of continental sediments in the Clarence-Moreton Basin was accompanied by subsidence. We suggest that the alternating rifting episodes and contraction were ultimately controlled by plate boundary migration and switches between trench retreat and advance during the Triassic. 相似文献
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The ～E–W-trending Olepoloko Fault and ～ENE-trending Louth-Eumarra Shear Zone in north-central New South Wales are approximately orthogonal to the dominant ～N–S-trending structural grain of Paleozoic eastern Australia. These structures have been interpreted to represent the boundary between the Thomson and Lachlan orogens, but their exact geometry and kinematics remain unclear owing to the scarcity of surface exposure. Using gridded aeromagnetic data and limited field mapping, we obtained new data on the tectonic history of the Louth-Eumarra Shear Zone, which seems to represent a broad zone of dextral shearing with a component of crustal thickening indicated by the recognition of kyanite growth in a mica-schist. The timing of deformation is relatively poorly constrained, but at least a component of the dextral shearing appears to be coeval or younger than the age of displaced late Silurian and Early Devonian granitoids. Additional indicators for dextral kinematics farther north, along the ～ENE-trending Culgoa Fault, suggest that the width of the zone that was subjected to dextral deformation is possibly >100 km. This raises the possibility that a large component of dextral displacement was accommodated in this region. In a broader geodynamic context, we discuss the possibility that the precursor of the Louth-Eumarra Shear Zone and Olepoloko Fault originated from segmentation between the northern and southern Tasmanides, perhaps during the Cambrian. The existence of such a discontinuity may have buttressed the process of oroclinal bending in the Silurian. The observed dextral kinematics has possibly resulted from reactivated deformation during the Tabberabberan and Alice Springs orogenies. 相似文献
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