Endorheic basins(ENBs) are inland drainage basins allowing no outflow to oceans.These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climat...Endorheic basins(ENBs) are inland drainage basins allowing no outflow to oceans.These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climate condition.The Zagros Mountains of Iran is one of the youngest convergence zones in which continental-continental collision has occurred.In this paper we hypothesize the formation of ENBs among the Zagros range after the epeirogenic stage in the Late Paleogene-Early Neogene.Due to tectonic activity and Quaternary climatic conditions,the ENBs pass the transition stage to exorheic,and still,some tectonic depressions are not linked to the evolutionary process of exorheic drainage of Zagros.The geometry of the drainage network of Kul and Mond basins in Fars arch shows that 67% of their water gaps are located along the thrusts and transverse basement faults in the east and west of the Fars arch.Geometrically,the Kul and Mond basins form triangles with their sides matching with the edges of the Arabian Plate where the major inherited faults of Arabian plate controls the shape of the Zagros basin and a low strain zone along the Razak fault with lower salt tectonic activity,where the wind gaps are created.The ENBs are located in the rainshadow slopes,but the Kul and Mond basins are located in the upwind slopes of rain waves.This factor and the heavy rains of the basin lead to increase of the erosion potential,destruction of depressions,and floods and consequently,the funnel-shaped gaps have a significant impact on the flood flow.展开更多
Alternation of high and low resistance sedimentary beds,active tectonics,large rivers,and slope erosion in valleys consequently resulted in landslide in dammed lakes within the Zagros range.This study presents the res...Alternation of high and low resistance sedimentary beds,active tectonics,large rivers,and slope erosion in valleys consequently resulted in landslide in dammed lakes within the Zagros range.This study presents the results in the analysis of geological and topographic data,satellite imageries,morphotectonics and hydrodynamics of drainage networks about the landslide dammed lakes.There are four landslides in central Zagros(Zagros FoldThrust Belt,ZFTB)which have formed five dammed lakes named,Seymareh,Jaidar,Shur,Shimbar,and Godar.According to the results,damming landslides occurred in the active-tectonic regions on the slopes of anticlines and in valleys with undercutting effects of rivers on their slopes consisting of alternations of loose and resistant beds.The studied landslide dams in narrow valleys are formed as a result of blocking river by sliding debris slopes and rock slides.This study also indicates the formation of Jaidar and Godar in one stage and the presence of Lake Terrace sequence in Seymareh,Shur and Shimbar lakes.The observed sequences of terrace formation in these lakes are caused by four Seymareh Landslides followed by the three-stage excavation of Shur andShimbar lakes.展开更多
The groundwater may recharge the surface water bodies through seepage faces and springs.The spatial correlation between the fault zones and the groundwater seepage faces results in deep understanding of the hydrogeolo...The groundwater may recharge the surface water bodies through seepage faces and springs.The spatial correlation between the fault zones and the groundwater seepage faces results in deep understanding of the hydrogeologic regime,especially where there is no monitoring boreholes.Locating these recharging zones by conventional methods is a challenging task;particularly in areas where(1)there is no hydrogeologic monitoring boreholes or reliable data,(2)private pumps withdraw the stream,and(3)intense canopy limits the use of drones and satellite images.This paper aims to study the relationship between the fault zones and occurrence of the groundwater seepage faces by using the high resolution handheld thermal imaging cameras as a tool to locate the seepage faces along a small river in the Damavand County,north of Iran.The correlation between the structural geology features and occurrence of the groundwater seepage faces revealed that the stream in the study area is being recharged by the groundwater at extensive fault zones.Additionally,this study suggests that the handheld thermal imaging cameras are a useful robust tools to evaluate the surface-groundwater interaction.However,it is essential to use the field structural geologic and hydrogeologic observations to interpret the thermal images.展开更多
Early in the 1930 s,two relatively large earthquakes(Kosout,magnitude 6.8,and Talarrud,magnitude 5.8)shook the eastern Mazandaran,northern Iran.Despite the historical and instrumental seismic activity of the eastern r...Early in the 1930 s,two relatively large earthquakes(Kosout,magnitude 6.8,and Talarrud,magnitude 5.8)shook the eastern Mazandaran,northern Iran.Despite the historical and instrumental seismic activity of the eastern region of Mazandaran,little is known about the status of seismotectonics and consequences of these earthquakes.This paper presents a compilation of available data from early reports of these earthquakes with new structural,geomorphic and local data on the effects of this earthquake,especially co-seismic landslides and liquefaction,to assess the seismotectonics and probable causative faults of the earthquakes.It is proposed that the close times of occurrence of two earthquakes might be due to local loading or triggering effect of the first earthquake on the second one.Like many other instrumental earthquakes in the Central Alborz,it is difficult to find the exact causative faults of important earthquakes,however the Qadikola,Chachkam or North Alborz Fault have the potential of producing Kosout earthquake and the Lalehband fault is more promising for Talarrud earthquake.Additionally,the structural complexity of the area is also discussed in the form of a hybrid tectonic model.In this model,the boundary zone of thick-skinned and active thin-skinned domains has more structural complexity than outer portions.Konim-Badeleh Shahvar pop-up structure is bounded by major faults with thick-skinned deformation style.The role of older inherited fault structures and their interaction with low-slope Neogene thrusts driven from north to south by crustal tectonics and deformation is discussed.Co-seismic landslides and rock falls have great potential to be investigated in the Alborz Range for identification of prehistoric earthquakes.展开更多
文摘Endorheic basins(ENBs) are inland drainage basins allowing no outflow to oceans.These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climate condition.The Zagros Mountains of Iran is one of the youngest convergence zones in which continental-continental collision has occurred.In this paper we hypothesize the formation of ENBs among the Zagros range after the epeirogenic stage in the Late Paleogene-Early Neogene.Due to tectonic activity and Quaternary climatic conditions,the ENBs pass the transition stage to exorheic,and still,some tectonic depressions are not linked to the evolutionary process of exorheic drainage of Zagros.The geometry of the drainage network of Kul and Mond basins in Fars arch shows that 67% of their water gaps are located along the thrusts and transverse basement faults in the east and west of the Fars arch.Geometrically,the Kul and Mond basins form triangles with their sides matching with the edges of the Arabian Plate where the major inherited faults of Arabian plate controls the shape of the Zagros basin and a low strain zone along the Razak fault with lower salt tectonic activity,where the wind gaps are created.The ENBs are located in the rainshadow slopes,but the Kul and Mond basins are located in the upwind slopes of rain waves.This factor and the heavy rains of the basin lead to increase of the erosion potential,destruction of depressions,and floods and consequently,the funnel-shaped gaps have a significant impact on the flood flow.
文摘Alternation of high and low resistance sedimentary beds,active tectonics,large rivers,and slope erosion in valleys consequently resulted in landslide in dammed lakes within the Zagros range.This study presents the results in the analysis of geological and topographic data,satellite imageries,morphotectonics and hydrodynamics of drainage networks about the landslide dammed lakes.There are four landslides in central Zagros(Zagros FoldThrust Belt,ZFTB)which have formed five dammed lakes named,Seymareh,Jaidar,Shur,Shimbar,and Godar.According to the results,damming landslides occurred in the active-tectonic regions on the slopes of anticlines and in valleys with undercutting effects of rivers on their slopes consisting of alternations of loose and resistant beds.The studied landslide dams in narrow valleys are formed as a result of blocking river by sliding debris slopes and rock slides.This study also indicates the formation of Jaidar and Godar in one stage and the presence of Lake Terrace sequence in Seymareh,Shur and Shimbar lakes.The observed sequences of terrace formation in these lakes are caused by four Seymareh Landslides followed by the three-stage excavation of Shur andShimbar lakes.
文摘The groundwater may recharge the surface water bodies through seepage faces and springs.The spatial correlation between the fault zones and the groundwater seepage faces results in deep understanding of the hydrogeologic regime,especially where there is no monitoring boreholes.Locating these recharging zones by conventional methods is a challenging task;particularly in areas where(1)there is no hydrogeologic monitoring boreholes or reliable data,(2)private pumps withdraw the stream,and(3)intense canopy limits the use of drones and satellite images.This paper aims to study the relationship between the fault zones and occurrence of the groundwater seepage faces by using the high resolution handheld thermal imaging cameras as a tool to locate the seepage faces along a small river in the Damavand County,north of Iran.The correlation between the structural geology features and occurrence of the groundwater seepage faces revealed that the stream in the study area is being recharged by the groundwater at extensive fault zones.Additionally,this study suggests that the handheld thermal imaging cameras are a useful robust tools to evaluate the surface-groundwater interaction.However,it is essential to use the field structural geologic and hydrogeologic observations to interpret the thermal images.
基金funded by the first author’s grant at Shahid Beheshti University。
文摘Early in the 1930 s,two relatively large earthquakes(Kosout,magnitude 6.8,and Talarrud,magnitude 5.8)shook the eastern Mazandaran,northern Iran.Despite the historical and instrumental seismic activity of the eastern region of Mazandaran,little is known about the status of seismotectonics and consequences of these earthquakes.This paper presents a compilation of available data from early reports of these earthquakes with new structural,geomorphic and local data on the effects of this earthquake,especially co-seismic landslides and liquefaction,to assess the seismotectonics and probable causative faults of the earthquakes.It is proposed that the close times of occurrence of two earthquakes might be due to local loading or triggering effect of the first earthquake on the second one.Like many other instrumental earthquakes in the Central Alborz,it is difficult to find the exact causative faults of important earthquakes,however the Qadikola,Chachkam or North Alborz Fault have the potential of producing Kosout earthquake and the Lalehband fault is more promising for Talarrud earthquake.Additionally,the structural complexity of the area is also discussed in the form of a hybrid tectonic model.In this model,the boundary zone of thick-skinned and active thin-skinned domains has more structural complexity than outer portions.Konim-Badeleh Shahvar pop-up structure is bounded by major faults with thick-skinned deformation style.The role of older inherited fault structures and their interaction with low-slope Neogene thrusts driven from north to south by crustal tectonics and deformation is discussed.Co-seismic landslides and rock falls have great potential to be investigated in the Alborz Range for identification of prehistoric earthquakes.
