A multi-disciplinary study of deformation of the basaltic cover over fine-grained valley fills: a case study from Eastern Sardinia, Italy

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• 作者：Rita Deiana ; Iginio Dieni ; Francesco Massari…
• 刊名：International Journal of Earth Sciences
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：105
• 期：4
• 页码：1245-1255
• 全文大小：3,155 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Geology
  Geophysics and Geodesy
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1437-3262
• 卷排序：105

文摘

The Pliocene to Early Pleistocene volcanic activity which generated the basaltic plateau of the Orosei-Dorgali area in Eastern Sardinia led to the disruption of the local hydrographic network by damming some tracts of the fluvial valleys incised in the granite basement. This resulted in the formation of lacustrine basins, whose fine-grained fills were partly interfingered and eventually covered by younger lava flows. In the SW part of the plateau, close to the Galtellì village, a number of unknown depressions, locally named “Paules,” were formed. In order to reconstruct their subsurface structure, two electrical resistivity tomography surveys were carried out across these depressions. The geophysical results, which demonstrate the existence of a disrupted layered system, were used to build a numerical geomechanical model that suggest the depressions originated by local collapses of the basaltic cover due to the compaction of the underlying fine-grained valley fills.KeywordsPlio-Pleistocene basaltic plateauLoading subsidenceElectrical resistivity tomographyGeomechanical modeling