A Preliminary Study on the Soft-Sediment Deformation Structures in the Late Quaternary Lacustrine Sediments at Tashkorgan, Northeastern Pamir, China

2018 ◽  
Vol 92 (4) ◽  
pp. 1574-1591 ◽  
Author(s):  
Lianji LIANG ◽  
Fuchu DAI ◽  
Hanchao JIANG ◽  
Ning ZHONG
Keyword(s):  
Late Quaternary ◽  
Lacustrine Sediments ◽  
Soft Sediment ◽  
Deformation Structures ◽  
Sediment Deformation ◽  
Preliminary Study ◽  
Soft Sediment Deformation

scholarly journals The Use of Soft-Sediment Deformation Structures As Proxies For Paleoseismic Activity And Shaking: A Review

2021 ◽  
Author(s):  
Ning Zhong ◽  
Hanchao Jiang ◽  
Haibing Li ◽  
Dechen Su ◽  
Hongyan Xu ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Lacustrine Sediments ◽  
Seismic Hazard Assessment ◽  
Soft Sediment ◽  
Surface Rupture ◽  
Advantages And Disadvantages ◽  
Deformation Structures ◽  
Sediment Deformation ◽  
Soft Sediment Deformation

Abstract Quantifying the magnitude of an earthquake is very important for long-term and medium-term earthquake prediction, post-earthquake emergency rescue and seismic hazard assessment. Paleoseismology is the investigation of past earthquakes in the geological record, in particular their location, timing and size. Uncertainties remain in the paleoearthquake magnitudes determined by traditional surface rupture parameters, especially because most seismic events do not result in surface ruptures. In order to address the problem of magnitude evaluation of earthquakes that did not reveal major dislocations, this paper deals with the methods used to determine the seismic shaking intensity based on the types and forms of soft-sediment deformation structures, including maximum liquefaction distance, thickness of disturbed layer, empirical formulae, and thickness of rapidly deposited sand layer. Then we discuss and analyze these methods in terms of their theoretical basis, advantages and disadvantages, accuracy, applicability and problems. We chose two case studies: first, a typical seismics-related deposit (liquefied layer and dsirupted layer) represented by a seismite in the late-Pleistocene Lake Lisan section near Masada in the Dead Sea Basin; and second, the liquefied diapir triggered by an earthquake in the late-Quaternary lacustrine sediments at Luobozhai in the upper reaches of the Minjiang River, east Tibet. The six methods listed above are employed to determine earthquake magnitudes associated with the seismics-related deposit and liquefied diapir, yielding magnitudes of 5.5-6.5 and 6-7, respectively. The combination of the six methods, provided a new and relatively convenient method for determining seismic shaking, especially in lacustrine sediments. This study can serves as a valid reference for comparing methods of calculating the magnitude of a paleoearthquake based on surface rupture parameters, and provides a better understanding of the long-term seismic activity and risk in tectonically active regions.

scholarly journals Soft sediment deformation features in Dauki Fault region: Evidence of paleoearthquakes, Shillong Plateau, NE India

2021 ◽  
Author(s):  
B.V Lakshmi ◽  
Praveen B. Gawali
Keyword(s):  
Urban Areas ◽  
Late Quaternary ◽  
Soft Sediment ◽  
Shillong Plateau ◽  
Deformation Structures ◽  
Regional Deformation ◽  
Ne India ◽  
Deformation Features ◽  
Sediment Deformation ◽  
Soft Sediment Deformation

Abstract The northeastern region (NER) of India has a number of complex regional geological structures, out of which the Dauki fault (DF) is a prominent one. The E-W trending reverse DF, which is referred to go through the southern margin of Shillong Plateau (SP), have played major role in the regional deformation of the adjoining areas and was believed to be active during the Late Quaternary time. Previous paleoseismological studies conducted on the eastern and western part of the DF, Bangladesh, revealed that the fault ruptured in AD 849–920 and AD 1548 respectively. However there were no studies on the DF from southern side of the SP, India. For the first time, from Indian side, soft sediment deformation structures (SSDS) are reported from five trenches in and around the DF zone, SP. Close to the Dauki village, five trenches in the eastern part of the DF, SP, show presence of micro faulting, sand dykes, disturbed strata, and water escape structures. The detailed investigation of SSDS indicates that the origin for deformation is seismic trigger. The 14C AMS dating of deformation structures generated coseismically by earthquakes suggest three seismic events occurred between 130 and 920 year BP, 5415 to 9140 year BP, and at about 4285 year BP. This study confirms that DF is indeed active, at least, since the mid-Holocene. More trenching and dating of seismically induced deformation features are needed to accurately calculate the recurrence interval of major earthquakes that can strike the fast-expanding urban areas in India and Bangladesh.

Soft-sediment deformation structures induced by seismic activity in the San Pedro el Alto area, Acambay graben, Mexico

2018 ◽  
Vol 35 (1) ◽  
pp. 28-40 ◽  
Author(s):  
M. Magdalena Velázquez-Bucio ◽  
Víctor Hugo Garduño-Monroy
Keyword(s):  
Sediment Cores ◽  
Lacustrine Sediments ◽  
Soft Sediment ◽  
Shape Distribution ◽  
Volcanic Material ◽  
Deformation Structures ◽  
San Pedro ◽  
El Alto ◽  
Sediment Deformation ◽  
Soft Sediment Deformation

Soft-sediment deformation structures identified in lacustrine sediments of the San Pedro el Alto area, within the Acambay graben, Mexico, can be attributed to Pleistocene-Holocene seismic events. The analysis of these deformation structures, seismites, is a key tool for the characterization of parameters such as the intensity and magnitude of the events, and the measurement of the affected area. Analysis of the shape, distribution, abundance and genesis of these secondary structures in lacustrine basins, also provide guidelines for assessing seismic hazard. The analysis of seismites enabled the identification of three M ≥ 5 earthquakes, minimum magnitude required for the formation of such structures, these on ESI 2007 scale (Environmental Seismic Intensity Scale) correspond to VII-X intensities. The structures were identified with coseismic stratigraphy analysis in three trenches and three sediment cores from the dam within the locality. The basin infill consists of lacustrine sediments with intercalation of volcanic material. The soft-sediment deformation structures appear in different sectors of the study area and consist of surficial ruptures, vertical displacements, slumps, pseudonodules, clastic dikes, cracks filled with recent material, and diapir-like and load-flame structures.

3D soft-sediment deformation structures: evidence for Quaternary seismicity in the Madrid basin, Spain

Terra Nova ◽  
1997 ◽  
Vol 9 (5) ◽  
pp. 208-212 ◽  
Author(s):  
P.G. Silva ◽  
J.C. Canaveras ◽  
S. Sanchez-Moral ◽  
J. Lario ◽  
E. Sanz
Keyword(s):  
Soft Sediment ◽  
Deformation Structures ◽  
Sediment Deformation ◽  
Soft Sediment Deformation

Dead Sea shoreline facies with seismically-induced soft-sediment deformation structures, Israel

2000 ◽  
Vol 49 (4) ◽  
pp. 197-214 ◽  
Author(s):  
Dan Bowman ◽  
Dorit Banet-Davidovich ◽  
Hendrik J. Bruins ◽  
Johannes Van der Plicht
Keyword(s):  
Dead Sea ◽  
Soft Sediment ◽  
Deformation Structures ◽  
Sediment Deformation ◽  
Soft Sediment Deformation
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