Arcuate Thrust Systems in Sandbox Experiments:
A Comparison to the External Arcs of the
Ford, Mary1, Henry Lickorish2, Judith Buergisser3, Peter R. Cobbold4 (1) Nancy School of Geology, ENSG-CRPG, Nancy, France (2) Rock Deformation Research, Calgery, Alberta (3) Dr. Henrich Jaeckli AG, Baden, Switzerland (4) Rennes University, Rennes, France
In the external western
Sandbox experiments investigate the role of the motion vector of a rigid rectangular indentor (orthogonal, diagonal, curved or rotational paths) and the mechanical stratigraphy of the foreland in the evolution of upper crustal arcuate systems (e.g. presence of a basal easy-slip (silicone) horizon). Comparison of experimental results with the external alpine arc suggest that the alpine indentor followed a slightly diagonal path with respect to the European margin from the Eocene to the early Miocene and curved anticlockwise by 10-15° in the mid-Miocene. Mechanical stratigraphy experiments support the hypothesis that thick Triassic evaporites played a primary role in the evolution of the Jura arc. The influence of mechanical stratigraphy was most prominent during weak deformation at the external boundaries of the Alpine orogen (Jura fold belt, Digne Thrust).