Abstract

There are a large number of thrust-faults related landforms distributed across the Planet Mercury, which are interpreted as the result of lithospheric deformation mainly attribute to secular cooling of the planetary interior. Exploring the mechanisms for formation of thrust-faults is a key to understand the evolutionary history of Mercury. As the largest single volcanic deposit on Mercury, the northern smooth plains incubates numerous shortening features in which present particularity in their tectonic patterns and require an assumed stratified subsurface structure. In this work, we propose a thermo-dynamic model from the perspective of temperature, rheological laws and strain rate, to study the formation of the thrust-faults related landforms in the northern smooth plains of Mercury under low strain rate via two-dimensional viscoelastic-plastic numerical simulations. Our simulation starts at 3.8 billion years ago and lasts for 70 million years, resulting in a stable and concentrated high strain rate region within the crust and geomorphic consistent surface topography with typical shortening landforms. This work refines the commonly used lithospheric mechanical model of Mercury and emphasizes the importance and sensitivity of the relationship between the surface topography and the relief at the crust-mantle boundary. Future studies can be extended to higher dimensions on this basis to study the distribution, orientation and other characteristics of the thrust-faults related landforms on Mercury.