What do pallasite meteorites tell us about processes deep in the interior of differentiated planet(essimal)s?

理论和数值研究表明，外核区域的化学不均匀性深刻地影响着地核和地幔的动力学和演化，以及地磁场的行为。然而，我们目前对这种异质性知之甚少。例如，地核-地幔边界的异常地震信号给出了最外层地核中地球化学不均匀性的诱人暗示，但我们星球的这一区域绝不是直接进行地球化学调查的地方（尽管像“The Core”这样的电影会让你相信）。原子模型对地幔最深处的化学成分提供了一些限制，地球物理模型技术可用于预测最外层地核的地球化学异质性。帕拉斯陨石可能来自于分化的微行星体，在太阳系早期的历史中，微行星体与大的火流星碰撞而破碎成碎片。这些陨石可能提供间接证据，可以测试地球深处的过程。该项目将综合利用对帕拉斯陨石的地球化学调查、对地球最外层内核成分的地球物理建模和对平衡金属/硅酸盐成分的原子建模，以调查帕拉斯陨石的性质和起源以及它们包含哪些关于行星体分化过程的信息。

Theoretical and numerical studies indicate that chemical heterogeneity in the outer core region profoundly influences the dynamics and evolution of Earth's core and mantle, and the behaviour of the geomagnetic field. However, we presently don't know much about this heterogeneity. For example, tantalizing hints of geochemical heterogeneity in the outermost core are given by anomalous seismic signals at the core-mantle boundary, but this region of our planet is by no means accessible for direct geochemical investigation (despite what movies such as "The Core" would have you believe). Atomistic modelling provides some constraints on what chemical composition could be expected in the deepest portions of the mantle and geophysical modelling techniques can be used to predict geochemical heterogeneity within the outermost core. Pallasite meteorites may be derived from differentiated planetesimals, subsequently smashed into fragments by collisions with large bolides early in the history of the solar system. These meteorites may provide indirect evidence with which processes deep within the Earth can be tested. This project will use a combination of geochemical investigations of pallasite meteorites, geophysical modelling of the composition of the Earth's outermost core and atomistic modelling of equilibrium metal / silicate compositions to investigate the nature and origin of pallasite meteorites and what information they contain regarding differentiation processes in planetary bodies.