DOI: 10.1016/j.quascirev.2014.02.015
Scopus记录号: 2-s2.0-84896312186
论文题名: Mid-Holocene cluster of large-scale landslides revealed in the Southwestern Alps by 36Cl dating. Insight on an Alpine-scale landslide activity
作者: Zerathe S. ; Lebourg T. ; Braucher R. ; Bourlès D.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 90 起始页码: 106
结束页码: 127
语种: 英语
英文关键词: 4.2ka event
; Alps
; Climate
; Cluster
; Cosmic ray exposure dating
; Large landslides
; Triggering factor
Scopus关键词: Chlorine compounds
; Glacial geology
; Limestone
; Lithology
; Rocks
; Unloading
; 4.2ka event
; Alps
; Climate
; Cluster
; Triggering factors
; Landslides
; chert
; cosmic ray
; electrical resistivity
; high pressure
; Holocene
; landslide
; limestone
; lithology
; mapping
; mudstone
; rainfall
; resolution
; rock
; unloading
; Alps
英文摘要: Although it is generally assumed that the internal structure of a slope (e.g. lithology and rock mass properties, inherited faults and heterogeneities, etc.) is preponderant for the progressive development of large-scale landslides, the ability to identify triggering factors responsible for final slope failures such as glacial debuttressing, seismic activities or climatic changes, especially when considering landslide cluster at an orogen-scale, is still debated. Highlighting in this study the spatial and temporal concordant clustering of deep-seated slope failures in the external Southwestern Alps, we discuss and review the possible causes for such wide-spread slope instabilities at both local and larger (Alpine) scale.High resolution field mapping coupled with electrical resistivity tomography first allows establishing an inventory of large landslides in the Southwestern Alps, determining their structural model, precising their depth limit (100-200m) as well as the involved rock volumes (>107m3). We show that they developed in the same geostructural context of thick mudstone layers overlain by faulted limestone and followed a block-spread model of deformation that could evolve in rock-collapse events.Cosmic ray exposure dating (CRE), using both 36Cl and 10Be in coexisting limestone and chert, respectively, has been carried out from the main scarps of six Deep Seated Landslides (DSL) and leads to landslide-failure CRE ages ranging from 3.7 to 4.7ka. They highlighted: (i) mainly single and fast ruptures and (ii) a possible concomitant initiation with a main peak of activity between 3.3 and 5.1ka, centered at ca4.2ka.Because this region was not affected by historical glaciations events, landslide triggering by glacial unloading can be excluded. The presented data combined with field observations preferentially suggest that these failures were climatically driven and were most likely controlled by high pressure changes in the karstic medium. In effect, the chronicle of failure-ages is concomitant to a well-known climatic pulse, the "4.2ka" climate event characterized by intense hydrological perturbations associated to the heaviest rainfall period of the entire Holocene. Despite requiring further investigations and discussions, the dating of numerous events across the entire Alps during the middle Holocene period suggests a potential synchronous triggering of several large-scale gravitational-failures induced by the mid-Holocene climatic transition. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60331
Appears in Collections: 过去全球变化的重建
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作者单位: Université de Nice Sophia-Antipolis, Centre National de la Recherche Scientifique (UMR 7329), Observatoire de la CÔte d'Azur, Géoazur, 250 av Albert Einstein, 06560 Valbonne, France; Aix-Marseille Université, CNRS-IRD-Collège de France, UM 34 CEREGE, TechnopÔle de l'Environnement Arbois-Méditerranée, BP80, 13545 Aix-en-Provence, France
Recommended Citation:
Zerathe S.,Lebourg T.,Braucher R.,et al. Mid-Holocene cluster of large-scale landslides revealed in the Southwestern Alps by 36Cl dating. Insight on an Alpine-scale landslide activity[J]. Quaternary Science Reviews,2014-01-01,90