Document Type : Original Research Paper
Authors
1 M.Sc., Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
2 Assistant Professor, Mine Department, Faculty of Engineering, Tehran University, Tehran, Iran
3 Associate Professor, Basic Science Faculty, Islamic Azad University, North Tehran Branch; Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
4 Assistant Professor, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
Abstract
The Oligocene salt in the Garmsar and Eyvankey plateau, south–central Alborz, has extruded on the quaternary sediments and formed a salt glacier. This open-toe salt glacier is about 24×17 km that is unique continental salt glacier in the world, dimensionally. Also, this ductile substrate has affected on structural styles of this region. However, little systematic work has done on it. To investigate the structural styles of the region that affected by a ductile substrate and adjacent region with a frictional decollement, and also the structures of the salt glacier,series of models were done which were scaled sandbox models. These sandbox models simulated the propagation of deformation of thin-skinned simultaneous shortening above adjacent ductile and frictional of two end member of decollement. Model results illustrate that above a ductile substrate, deformation propagates further and more rapidly than above a frictional substrate as we can see in the nature that the region with a ductile substrate is so broader than the adjacent region with a frictional decollement. Like the models, toward the north in the nature where the Decollement is frictional, from North Tehran Fault as a frontal fault to Mosha and Kandovan Faults in the core of Alborz Mountain, the dip of the faults are increased and only forward-vergent imbricate faults, whereas above the ductile substrate the dip of faults has not a definite pattern of dip and also, both foreland and hinterland imbricate faults develop.
Keywords
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