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

火星、金星和类似的单板块行星的二维和三维对流和熔融模型将与矿物学和地幔热弹性特性模型相结合，以模拟这些行星自44 - 45亿年前地幔凝固以来的演变，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寿的火山中心的形成。中心方面是地幔矿物相变对全球对流模式和地幔柱动力学的影响，以及微量成分（放射性核素和挥发物）及其通过对流、熔融和火山作用重新分布的影响。由于对地幔组成和地核比的认识有限，某些模型参数如地幔厚度、镁铁比、放射性核素和水的含量等会发生变化。此外，还将探讨地表温度的影响，就火星而言，还将探讨岩石圈横向温度和厚度变化的影响，例如由地壳二分法引起的影响以及古代成分非均质性的作用。在这种情况下，将考虑与火星或金星无关但具有普遍意义的参数组合，例如系外行星。这些模型将产生可与实际观测相比较的地球物理和地球化学观测结果。

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.