Interactions between salt tectonics and crustal tectonics in the Mediterranean and in the Barents sea
Considering geological times, the behaviour of the salt can be approximated to a Newtonian fluid (i.e. viscous behaviour) compared to the brittle behaviour of the surrounding rocks, and their interaction can be modelled through scaled analogue models of a viscous material and a brittle one, e.g. sil...
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| Other Authors: | , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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HAL CCSD
2022
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| Subjects: | |
| Online Access: | https://theses.hal.science/tel-04476984 https://theses.hal.science/tel-04476984/document https://theses.hal.science/tel-04476984/file/These_TRAVAN_Gaia.pdf |
| Summary: | Considering geological times, the behaviour of the salt can be approximated to a Newtonian fluid (i.e. viscous behaviour) compared to the brittle behaviour of the surrounding rocks, and their interaction can be modelled through scaled analogue models of a viscous material and a brittle one, e.g. silicone and sand. Crustal tectonics, both extensional and contractional, have often a fundamental role in the evolution of the salt structures, and becomes the main cause of deformation in many study areas. The aim of this thesis is to analyze the timing and mechanisms of salt tectonics in three study area characterized by different salt ages and increasing influence of crustal tectonics on the salt tectonics processes: the Western Sardinian and Northern Algerian margin (Western Mediterranean) and the Sørvestsnaget Basin (Southwestern Barents Sea). This has been done through the interpretation of 2D and 3D seismic reflection data from TGS (Norway), OGS (Italy) and UMR Geo-Ocean (France), as well as through the integration with other geophysical data, wells data and the comparison with analogue models. In the W-Mediterranean the salt deposited during the Salinity Crisis (5.6 Ma) so salt tectonics is relatively young, the overburden is thin and the marks of the first stages of deformation are usually imaged. On the W-Sardinian margin the salt structures are mainly consequence of the basinward slope of the salt base, resulting from the differential subsidence after the refilling of the Mediterranean at the end of the crisis. Moving towards the center of the Sardo-Provencal basin, where the sedimentary load of the Rhone Deep Sea Fan forms a thick salt overburden, gravity spreading dominates. While in this area there is no influence of crustal tectonics on salt deformation at a regional scale, we recognized on the SW-Sardinian margin the presence of a flower structure active during Pliocene. We propose it to be part of the North Balearic Fracture Zone, i.e. the dextral strike-slip fault of the Sardo-Provençal basin opening, ... |
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