Formation of Martian Wrinkle Ridges: New Insights From Analog Experiments on Décollement Processes

Abstract

Wrinkle ridges on Mars, resulting from crustal contraction and tectonic deformation, provide crucial records of tectonic strain. This study presents a possible model based on analog experiments to investigate the influence of varied décollement properties, quantities, and blind thrust faults on the formation of Martian wrinkle ridges. Results indicate that brittle décollements facilitate symmetric ridges with similar primary thrust and backthrust dip angles, whereas ductile décollements promote arch-style ridges with high-angle forelimbs and low-angle backlimbs. Folding is more significant in a single low-viscosity ductile décollement. Blind thrust faults combined with double-layer low-viscosity ductile décollements are crucial for forming typical double ridges, characterized by a broad arch and a narrow ridge. The study suggests that the number, viscosity, distribution of décollements, and rheological properties of décollement influence surface morphology. Comparing these results with Martian observations elucidates factors influencing wrinkle ridge morphology, offering new insights into the tectonic evolution of Martian geological structures and the prediction of potential subsurface décollements, such as those associated with variations in water ice concentrations.