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neotectonics of Kashaf Rud River, NE Iran by Modified Index of Active Tectonics (MIAT)

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International Journal of Geosciences 2015年第7期6卷 776-794页

作者： ElaheJavadi Mosavi Mehran Arian Department of Geology Science and Research Branch Islamic Azad University Tehran Iran

Kashaf rud river is located in border zone of East Alborz and Kopet Dagh physiographic provinces in the north east Iran. Geomorphic indices are useful tools to show the neotectonic regimes. These indices have got the advantage of being calculated from Arc GIS and remote sensing packages over large area as a useful tool to identify geomorphic anomalies possibly related to active tectonics. In this research, seven geomorphic indices (stream-gradient index, valley floor width-valley height ratio, mountain-front sinuosity, drainage basin asymmetry, hypsometric integral, drainage basin shape and transverse topographic symmetry factor) were calculated along the Kashaf rud river. Then, based on a new index or modified index of active tectonics (Miat) values that calculated by average of seven geomorphic indices, relative tectonic activities levels were revealed. The low class of Miat is mainly in the sub-basins of No. 6, 10, 13, 14, 21, 22, 23, 24 & 28 while the rest of the study area has moderate tectonic activities in the other sub-basins. Our results show that the moderate value has located along faulted area, which shows 2 class of relative tectonic activity. These faults have been formed above an old suture zone between Cimmerian and Eurasian plates.

关键词： neotectonics Miat Geomorohic Index Kashaf Rud Iran

SEA LEVEL RISE OF THE ZHUJIANG RIVER DELTA AND neotectonics

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Chinese Geographical Science 1993年第1期3卷 46-52页

作者：曾昭璇刘南威胡男丘世钧黄山李平日方国祥黄光庆祝功武

A linear regression analysis of 28 selected tide-gauge stations of the Zhujiang Estuary shows that there has been a tendency of local sea level rise at a rate of 2.028 mm per year. The origin of the variation is significantly attributed to the local tectonic movement of discrepant fault-block. Based on this, four types of relative local sea level changes are classified. According to calculation, half of the fertile land, or 800 km2 of the delta plain will have been submerged by sea water by about 2040. This will yield a significant influence on the economic construction and human activities.

关键词： sea level rise the Zhujiang River Delta neotectonics

neotectonics of Boroujerd Area, SW Iran by Index of Active Tectonics

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Open Journal of Geology 2015年第5期5卷 309-324页

作者： Maryam Omidali Mehran Arian Ali Sorbi Department of Geology Science and Research Branch Islamic Azad University Tehran Iran Department of Geology Karaj Branch Islamic Azad University Karaj Iran

Boroujerd area has located in the border zone of Zagros mountain and Sanandaj-Sirjan belt in the southwest Iran. Six geomorphic indices were calculated in the study area. Through averaging these indices we obtain index of active tectonics (Iat). The values of the index were divided into classes to define the degree of active tectonics. Therefore, relative tectonic activity was calculated and their values were classified and analyzed in two groups. Regions were identified as low and moderate levels. In analyzing data and combining them with tectonic setting the results were often associated and justified with regional geology. Our results show that the highest value has located along faulted area, which shows 3 classes of relative tectonic activity (moderate level). Also, other values have located along folded area (low level). Therefore, middle part of study area (sub-basin No. 4) is showing the more active uplifting related to surroundings region (sub-basin No. 1, 2 and 3). In other words, sub-basin No. 4 has got the more active uplifting by quaternary movements of several faults such as Doroud fault.

关键词： neotectonics Geomorohic Index Boroujerd Zagros Iran

Partitioning Anatolian Kinematics into Tectonic Escape and Slab Rollback Dominated Domains

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Journal of Earth Science 2024年第3期35卷 758-768页

作者： Jiannan Meng Timothy M.Kusky Erdin Bozkurt Hao Deng Ozan Sinoplu State Key Laboratory of Geological Processes and Mineral Resources Center for Global TectonicsSchool of Earth SciencesChina University of GeosciencesWuhan 430074China Badong National Observatory and Research Station for Geohazards China University of GeosciencesWuhan 430074China Department of Geological Engineering Middle East Technical University06800 AnkaraTurkey Department of Geosciences Auburn UniversityAuburn AL 36849USA

Anatolia is the global archetype of tectonic escape,as witnessed by the devastating 2023 Kahramanmaraş Earthquake sequence,and the 2020 Samos Earthquake,which show different kinematics related to the framework of the escape *** Positioning System(GPS)motions of the wedge-shaped plate differ regionally from northwestwards to southwestwards(from east to west).Anatolia was extruded westward from the Arabian-Eurasian collision along the North and East Anatolian fault systems,rotating counterclockwise into the oceanic free-faces of the Mediterranean and Aegean,with dramatic extension of western Anatolia in traditional ***,which is the dominant mechanism for this change in kinematics,extrusion related to the Arabia/Eurasia collision or rollback of the African slab beneath western Anatolia is still *** assess the dominant driving mechanisms across Anatolia,we analyze recent GPS velocity datasets,and decomposed them into N-S and E-W components,revealing that westward motion is essentially constant across the whole plate and consistent with the slip rates of the North and East Anatolia fault zones,while southward components increase dramatically in the transition area between central and western Anatolia,where a slab tear is *** phenomenon is related to different tectonic driving *** ArabiaEurasia collision drives the Anatolian Plate uniformly westwards while western Anatolia is progressively more affected by the southward retreating African subducting slab west of the Aegean/Cypriot slab tear,which significantly increases the southward component of the velocity field and causes the apparent curve of the whole modern velocity *** 2020 and 2023 earthquake focal mechanisms also confirm that the northward colliding Arabian Plate forced Anatolia to the west,and the retreating African slab is pulling the upper plate of western Anatolian apart in *** propose that the Anatolian Plate is moving westwards as

关键词： tectonics neotectonics tectonic escape slab rollback Anatolian Plate GPS velocity field geodynamics.

Magnetic fabric and geomorphic characteristic of Neotectonic activity along strike direction of North Almora Thrust,Kumaun Lesser Himalaya,India

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Geodesy and Geodynamics 2022年第3期13卷 261-274页

作者： Ritu Chauhan Girish Ch Kothyari Surendra S.Bhakuni Pitamber Dutt Pant Ajay Kumar Taloor CAS in Geology Kumaun UniversityNainitalIndia Institute of Seismological Research RaisanGandhinagar382009India Wadia Institute of Himalayan Geology DehradunIndia Department of Remote Sensing and GIS University of JammuJammuIndia

Structurally,the North Almora Thrust(NAT),is placed in the northern proximity of the Almora Nappe(AN)in the Kumaun Lesser *** NAT is characterized by the presence of a zone of mylonitic rocks of basal Saryu Formation(1800±100 Ma)in the hanging wall and the metasedimentaries of Inner Lesser Himalayan rocks as the footwall *** NAT has been dextrally offset by two estabilished maj or faults *** River Fault(SRF)in Saryu Valley and Dwarahat-Chaukhutia Fault(DCF)in Ramganga *** present study,we identified four new faults,based on field study,geomorphic landform and magnetic fabric *** faults are N-S trending Pancheshwar Fault,NE-SW Rameshwer Fault,NNE-SSW trending Kosi Fault,and NNE-SSW trending Gagas Fault(GF).Our results show that the zone is bound by cross cutting relation with NAT and these fault zones are comparatively more active than other ***,we suggest that the steep and NW-SE orientation of magnetic foliation within the NAT zone is a result of NE-SW oriented progressive regional *** magnetic foliations represent the unseen internal foliations in the rocks developed due to preferred alignment of magnetic minerals and can be found through the Anisotropy of magnetic susceptibility(AMS)*** in the alignment of the field and magnetic foliations are developed due to superimposed brittle deformation along the faults over the pre-existing field *** foliations represent the impact of last stage deformation and significant to find brittle deformation and finite strain in the rocks of the study *** lowering of anisotropy(Pj)away from the fault zone represents distribution of strain across the NAT *** fabric confirms the presence of faults developed across the NAT zone and also explains the deformation pattern along these *** geomorphic anomalies and steepness changes across the NAT zone are correlated with active deformation along the NAT and associated transverse

关键词： North Almora Thrust(NAT) Geomorphology Anisotropy of magnetic susceptibility neotectonics Kumaun Lesser Himalaya

Late Quaternary fluvial terrace formation in the Luan River drainage basin,north China and its possible linkages with climate change and tectonic activation

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China Geology 2023年第3期6卷 395-408页

作者： Yu-chen Tian Xu-jiao Zhang Zhi-qiang Yin Hai Shao Ming-xu Gu Yingying-Ding Chao Peng Xiang-ge Zhang School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China China institute of Geo-Environment Monitoring China Geological SurveyMinistry of Natural ResourcesBeijing 100081China Hebei geological environment monitoring Institute Shijiazhuang 050021China

The Luan River is the most important water system in north-eastern Hebei Province,China and is located in the transitional zone of the Eastern Yan Mountains,North China Plain and Songliao *** well-developed river terraces of its tributary,the Yixun River,provide excellent information for studying neotectonics and climate *** are seven terraces in the lower reaches of the Yixun River,numbered *** optically stimulated luminescence dating results of 23 samples show that terraces T7-T2 formed at 111.36±5.83 ka,78.20±4.45 ka,65.29±4.15 ka,56.44±3.07 ka,40.08±2.66 ka,and 13.14±0.76 ka,respectively.A comparison with the oxygen isotope curves of deep-sea sediments reveals that the sediment formation of each terrace corresponded to cold periods of marine isotope stages MIS 4 and MIS 2 and the relatively cold periods of MIS 5e,MIS 3,and MIS *** the Late Pleistocene,the incision rate of the Yixun River has ranged from 0.371-1.740 mm/*** the formation of T7-T6,T5-T4,T4-T3,and T3-T2,the incision rate was ***,in the two stages during which T6-T5 and T2-T1 formed(13.14±0.76 ka to 0.58±0.08 ka and 10.79±0.64 ka to 0.16±0.01 ka),these rates reached 1.554 mm/a and 1.592-1.740 mm/a,*** approximately 30 ka,the activity of the Langying Fault increased,leading to footwall *** river gathered in the north of Langying to form the ancient Erdaowan Lake,which resulted in the drying of the river in the lower reaches of the Yixun River during the last glacial maximum without forming river *** the Early Holocene,headward erosion in the lower reaches of the Yixun River was enhanced,which resulted in the disappearance of the lake,and incised meandering formed due to increased *** on the analyses of river incision and the formation of ancient lakes and incised meandering,it was inferred that there have been three periods of strong tectonism in the river basin since the Late Pleistocene.

关键词： River terrace Paleoclimate change Tectonic activation Optically stimulated luminescence dating Marine isotope stage Last glacial maximum neotectonics Geomorphology Geological survey engineering North China Plain

Focusing Seismic Energy along Faults through Time-Variable Rupture Modes: Wenchuan Earthquake, China

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Journal of Earth Science 2010年第6期21卷 910-922页

作者： Timothy M Kusky Abduwasit Ghulam 王璐刘建国李中全陈骁 Three Gorges Research Center for Geo-hazard Ministry of Education and State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Center for Environmental Sciences Saint Louis University Three Gorges Research Center for Geo-hazard Ministry of Education China University of Geosciences Department of Marine Geology Ocean University of China Department of Earth Science and Engineering Imperial College Department of Geosciences Chengdu University of Technology

Field analysis and differential interferometry derived from Synthetic Aperture Radar （PALSAR） of the epicentral area of the May 12 2008 Mw 8.0 Wenchuan （汶川） earthquake zone reveal details about fault ruptures and ground displacements, with field-documented vertical offsets reaching 12 m along the trace of the main fault rupture, and PALSAR-measured horizontal displacements reaching 12.3 m. We document slip indicators on the fault scarp that show initially sub-horizontal then progressively steeper slip increments with time along the same fault during the 2 min earthquake, suggesting that the rupture propagated as a mixed Mode Ⅱ-Ⅲ fracture, with strike-slip movement at the tip directing energy from the initial rupture to points north of the epicenter, followed by vertical displacement in the interior of the slipped region. Field, seismic, and PALSAR-measured displacements are dominantly thrust near the epicentral region, and dextral in northeasterly areas, showing that slipwas partitioned along the fault in space and time during the earthquake. The changing slip directions may correlate with three main pulses of energy release at 0, 23, and 57 s during the earthquake as recorded by seismograms. The earthquake generated massive landsfides 〉100 km north of the epicenter along the trace of the fault. These massive sturzstroms formed where entire mountainsides collapsed and moved at high velocity down populated mountain valleys, jumping smaller mountains and ricocheting off steep canyon walls. These avalanches rode on cushions of water and compressed air that generated air blasts from beneath the debris, knocking down trees high on opposing mountain slopes. The concentration of massive landslides and ground deformation so far north of the epicenter was related to the Mode Ⅱ-Ⅲ fracture propagation focusing seismic energy along the fault towards the north, explaining why so much devastation occurred 〉100 km from the epicenter, such as in the destroyed city of Beichuan （北川）.

关键词： China Wenchuan earthquake Longmenshan neotectonics PALSAR.

Neotectonic Indications from the Western and Southern Deserts of Iraq

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International Journal of Geosciences 2023年第5期14卷 427-436页

作者： Varoujan K. Sissakian Nadhir Al-Ansari Lanja H. Abdullah Jan Laue College of Engineering Komar University of Science and Technology Sulaymaniyah Iraq Department of Civil Environmental and Natural Resources Engineering Lulea University of Technology Lulea Sweden College of Science University of Sulaimani Sulaymaniyah Iraq

The Iraqi Western and Southern deserts are part of the Iraqi Stable Shelf (Inner Platform) that belongs to the Arabian Plate. Therefore, both deserts lack tectonic forms like folds and faults;however, very rarely faults and regional lineaments can be seen in both deserts. Although both deserts are tectonically stable, tens of Neotectonic indications can be seen everywhere in both deserts. Among those indications are: Straight valleys, perpendicular valley bendings, sinkholes aligned along straight lines, dislocated valleys, knickpoints within valleys aligned along straight lines, regional lineaments, anomalous valley shapes, trends, and types, dissected alluvial fans. We have used existing geological maps of different scales and Esri World Imagery to recognize those Neotectonic indications. All those recognized features are excellent indications that both the Iraqi Western and Southern deserts are tectonically not stable. Accordingly, new terminology is suggested instead of the Stable Shelf (Inner Platform) which is the “Less Disturbed Shelf”.

关键词： neotectonics Iraq Western and Southern Deserts Knickpoints Dislocated Valleys Anomalous Valley Shapes

Structural Development of Northwest Saudi Arabia Using Aeromagnetic and Seismological Data

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Journal of Earth Science 2016年第6期27卷 998-1007页

作者： Mohamed Fnais Elkhedr Ibrahim Essam Abd El-Motaal Kamal Abdelrahman Abdelmaguid Al-Heniedi Khaled Al-Kahtany Department of Geology and Geophysics King Saud University Riyadh 36002 KSA Department of Geology Faculty of Science Mansoura University Mansoura 21345 Egypt Department of Geology Faculty of Science Al-Azhar University Cairo 11435 Egypt Department of Seismology National Research Institute of Astronomy and Geophysics Cairo 11435 Egypt

High resolution aeromagnetic and seismological data constrained by field-based structural investigations have been used to map and delineate the structural elements that affected and shaped the Midyan area in the northwest part of Saudi Arabia. The area was divided into four major domains defined by NNE, NNW, NW and ENE trending faults identified by trends, patterns and intensity of magnetic anomalies. The ENE trending left-lateral strike-slip faults intersected by NNE trending faults are the predominant tectonic features in the Gulf of Aqaba coastal area and stop at the boundary of a central domain characterized by complexity in the pattern and intensity of magnetic anomalies, that may be attributed to heterogeneity of basement rocks containing complex igneous rock suites including diorite, gabbro, ultramafic and alkali granitic rocks. This domain is characterized by the presence of narrow linear magnetic anomalies that extend for kilometers in an NNW direction, indicating dikes intruded through NNW trending faults. These dikes become WNW-oriented near their northern termination by transfer of movement to WNW-oriented faults marking the northern termination of the Red Sea rift. It is believed that this fault zone is still experiencing neotectonic activity, as evident from recorded seismicity. The aeromagnetic structural resuits coincide with fault plane solutions for the largest earthquakes, confirming aeromagnetic interpreted trends and illustrating mixed mechanisms between extensional and strike-slip faulting. Thus the study area displays different mechanisms associated with different tectonic trends which show clearly in the structural patterns of the area.

关键词： aeromagnetism seismicity neotectonics Midyan area Saudi Arabia.