A geomechanical approach for the genesis of sediment undulations on the Adriatic shelf - art. no. Q04R03
|Author(s)||Sultan Nabil1, Cattaneo Antonio1, Urgeles R2, Lee H, Locat J3, Trincardi F4, Berne Serge1, Canals M2, Lafuerza S2|
|Affiliation(s)||1 : IFREMER, Dept Geosci Marines, F-29280 Plouzane, France.
2 : Univ Barcelona, GRC Geociencies Marines, Dept Estratig Paleontol & Geociencies Marines, E-08028 Barcelona, Spain.
3 : Univ Laval, Dept Geol & Geol Engn, Quebec City, PQ G1K 7P4, Canada.
4 : ISMAR, CNR, I-40129 Bologna, Italy.
|Source||Geochemistry Geophysics Geosystems - G3 (1525-2027) (American Geophysical Union), 2008-04 , Vol. 9 , N. 4 , P. NIL_1-NIL_25|
|WOS© Times Cited||23|
|Keyword(s)||Sediment deformation, Shear strength, Earthquake, Adriatic shelf|
|Abstract||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.|