Dynamical and chemical evolution of Mars- and Venus-like Planets

火星、金星和类似的单板行星对流和融化的2D和3D模型将与地幔的矿物学和热弹性模型相结合，以模拟这些行星自4.4-45亿年前地幔凝固以来的演化，并解释其表面的某些地质结构。特别令人感兴趣的问题包括它们的岩石圈的稳定性，金星上的各种火山结构，以及火星上两个明显长期存在的火山中心的形成。中心方面是地幔矿物的相变对全球对流模式和地幔热柱动力学的影响，以及痕量组分(放射性核素和挥发物)的影响及其通过对流、熔融和火山作用的重新分布。鉴于对地幔成分和地核比的了解有限，某些模型参数，如地幔厚度、镁铁比、放射性核素和水含量将有所不同。此外，还将探讨地表温度的影响，以及在火星的情况下，例如由地壳二分法引起的岩石圈横向温度和厚度变化的影响，以及古代成分不均一性的作用。在这方面，将考虑与火星或金星无关但普遍感兴趣的参数组合，例如关于系外行星。这些模型将产生可以与实际观测相比较的地球物理和地球化学观测数据。

2D and 3D models of convection and melting in Mars, Venus, and similar one-plate planets will be combined with models of the mineralogy and the thermoelastic properties of the mantle in order to simulate the evolution of these planets since solidification of the mantle 4.4-4.5 billion years ago, and to explain certain geological structures on their surface. Issues of particular interest include the stability of their lithospheres, the various volcanic structures on Venus, and the formation of two apparently long-lived volcanic centers on Mars. Central aspects are the effect of phase transformations of mantle minerals on global convection patterns and mantle plumes dynamics and the effect of trace components (radionuclides and volatiles) and their redistribution through convection, melting, and volcanism. In view of the limited knowledge of the composition and the mantle-to-core ratio certain model parameters such as the thickness of the mantle, the ratio of magnesium and iron, and the radionuclide and water content will be varied. Furthermore, the influence of surface temperature and, in the case of Mars, the effect of lateral temperature and thickness variations in the lithosphere caused, e.g., by the crustal dichotomy as well as the role of ancient compositional heterogeneities will be explored. In this context parameter combinations will be considered that are not relevant for Mars or Venus but are of general interest e.g. with respect to exoplanets. The models will yield geophysical and geochemical observables that can be compared with real observations.