Premium
Giant solution‐subsidence structure in the Western Mediterranean related to deep substratum dissolution
Author(s) -
Lofi Johanna,
Berné Serge,
Tesson Michel,
Seranne Michel,
Pezard Philippe
Publication year - 2012
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2011.01051.x
Subject(s) - geology , sinkhole , karst , subsidence , dissolution , quaternary , groundwater recharge , geomorphology , paleontology , geochemistry , groundwater , aquifer , geotechnical engineering , structural basin , chemistry
Terra Nova, 24, 181–188, 2012 Abstract Sinkholes are frequently observed where soluble rocks are present, in meteoritic recharge areas or when subsurface dissolution causes ground collapse. Seismic profiles on the inner shelf of the Gulf of Lions (W. Mediterranean) display a giant atypical sub‐circular structure, up to 800‐m thick and 2‐km wide. It is characterized by down‐warped internal seismic reflections forming a concave V‐shaped depression rooted in the substratum, most likely carbonated. This structure is interpreted as a poly‐phased solution‐subsidence/collapse structure of Plio‐Quaternary age. The last phase of deformation probably occurred during the last sea‐level low‐stand phase. The mechanism proposed for the creation of this structure is collapse/dissolution of the soluble substratum, as a result of a combination of several possible factors including pre‐existing deep Messinian palaeo‐karst with active groundwater flows during Plio‐Quaternary lowstands, and deep‐rooted acidic fluids ascending through the substratum.