Open AccessA geomechanical approach for the genesis of sediment undulations on the Adriatic shelf
Author(s) -
Sultan Nabil,
Cattaneo Antonio,
Urgeles Roger,
Lee Homa,
Locat Jacques,
Trincardi Fabio,
Berne Serge,
Canals Miquel,
Lafuerza Sara
Publication year - 2008
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2007gc001822
Subject(s) - geology , seafloor spreading , sediment , borehole , sedimentary depositional environment , continental shelf , geomorphology , geotechnical engineering , geophysics , oceanography , structural basin
This study is among the first to examine the genesis of the seafloor and subsurface undulations on the Adriatic continental shelf by integrating stratigraphic information and in situ and laboratory geotechnical measurements. Interpretation of sediment behavior is based on a 32‐m‐long borehole crossing (1) a possible shear plane and (2) a silty clay layer at about 20 m below seafloor (mbsf) on which sediment undulations are rooted and could be interpreted as a potential weak layer succession. Our main results in terms of triggering mechanism for the observed undulations show that under an earthquake, liquefaction and/or failure of the silty‐clay sediments (weak layer) leading to deformation of the upper more cohesive sediments is possible only when such a layer is buried by less than 5 m. For greater burial thicknesses, this silty clay becomes stable under the confining lithostatic pressure exerted by the overlying sediment. This work shows that the seafloor and subsurface undulations observed in the study area are most probably the result of an early deformation process of the seafloor followed by a depositional process.