From salt‐bearing rifted margins to fold‐and‐thrust belts. Insights from analog modeling and northern calcareous alps case study

Abstract

Analog modeling is used to study the role played by the inherited salt-sediment architecture of a salt-bearing rifted margin, developed by minibasin downbuilding and margin-scale gliding, and then incorporated into a fold-and-thrust belt system influenced by surface processes. Inherited salt bodies localize contractional deformation at different scales and the salt-sediment architecture determines structural styles of fold-and-thrust belts. In our analog models, a large-transport thrust detached along allochthonous model salt (silicone polymer) accumulated in a former distal raft system. And the squeezing of salt walls, together with the tilting of minibasins, accounted for most of the shortening in a salt wall-minibasin province. Shortening and surface processes promote the extrusion and erosion of about 75% of the original model salt. The role played by salt tectonics during the contraction of salt-bearing rifted margins could be underestimated because of the low salt-sediment ratio found in fold-and-thrust belts. Our modeling results are compared with and assist in the interpretation of a section along the Northern Calcareous Alps.