Seamount control during gravity-driven extension involving multi-layered evaporites

PreviousNext You have accessInternational Conference and Exhibition, Barcelona, Spain, 3-6 April 2016Seamount control during gravity-driven extension involving multi-layered evaporitesAuthors: Oriol FerrerEduard RocaOscar GratacósJosep Anton MuñozOriol FerrerUniversity of BarcelonaSearch for more papers by this author, Eduard RocaUniversity of BarcelonaSearch for more papers by this author, Oscar GratacósUniversity of BarcelonaSearch for more papers by this author, and Josep Anton MuñozUniversity of BarcelonaSearch for more papers by this authorhttps://doi.org/10.1190/ice2016-6284193.1 SectionsAbout ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract The Liguro-Provençal basin (Western Mediterranean) includes a thick multi-layered salt sequence composed by three evaporitic units (Lower, Mobile & Upper units) deposited in the deep basin during the Messinian salinity crisis (Upper Miocene). From these units, the Mobile unit (MU), formed basically by halite, is the weakest layer acting as an extensional detachment. It favoured the downslope gravitational failure of the overlying sediments controlling the structural style of this region. As a result, two different salt tectonics domains have been classically interpreted: an upper extensional domain characterized by basinward-dipping listric normal faults that sole into the MU, and a downdip contractional domain that accommodates the updip extension by folding, salt inflation or diapir squeezing. The base of the MU does not show significant regional topographic variations and is characterized by a gentle surface dipping basinward. However, several seamounts located in the upper extensional domain disrupt this surface constraining the salt flow. They developed previously to the salt deposition and are organized along a chain with a NNE-SSW trend. The seamounts acted as a passive buttress during the gravitational failure and developed a characteristic set of structures depending on their size, height and orientation. Listric faults dipping downslope developed in the seamount basinward flank when the MU is thicker than the height of the seamount. In this case, the upslope extension is accommodated in the landward flank of the seamount by salt inflation. Conversely, when the seamount is higher than the MU thickness, the buttressing produced by the seamount generated contractional structures in its landward flank. Different relay structures developed between these two cases. Using an experimental approach (sand-box models) this research analyses the role played by a volcanic chain in the upslope extensional domain of a passive margin including multi-layered post-rift evaporites. We characterize the internal deformation of the evaporites in response to these seamounts and how their orientation, shape and height constraint the development of extensional structures and the salt flow. The results of this experimental program are compared with a 2D seismic survey of the Liguro-Provençal basin suggesting a possible 3D structural evolution for the area. Keywords: modeling, tectonics, volcanics, salt, seismicPermalink: https://doi.org/10.1190/ice2016-6284193.1FiguresReferencesRelatedDetails International Conference and Exhibition, Barcelona, Spain, 3-6 April 2016ISSN (online):2159-6832Copyright: 2016 Pages: 356 publication data© 2016 Published in electronic format with permission by the Society of Exploration Geophysicists and the American Association of Petroleum GeologistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 03 Apr 2016 CITATION INFORMATION Oriol Ferrer, Eduard Roca, Oscar Gratacós, and Josep Anton Muñoz, (2016), "Seamount control during gravity-driven extension involving multi-layered evaporites," SEG Global Meeting Abstracts : 178-178. https://doi.org/10.1190/ice2016-6284193.1 Plain-Language Summary KeywordsmodelingtectonicsvolcanicssaltseismicLoading ...