Mineral records of magma storage and crystallization on the Moon

月球保留了一颗岩石小行星上火山活动的非凡记录。月球熔岩主要在大约43.5亿到30亿年前喷发，月球上的一些地区直到10亿年前才开始火山活动。月球熔岩来自月球地幔不同区域的部分熔融，导致了一系列的地球化学联系和结晶历史。不同的月球岩浆成分被认为是通过不同的储存和结晶途径到达月球表面的，但岩浆储存和结晶的压力和温度并不是很清楚。因此，该项目的目的是开发新的矿物熔融温压计，以调查月球上岩浆储存和结晶的记录。我们试图回答这样的问题：月球岩浆是在地壳糊状室中停滞和结晶，还是从熔融区迅速上升到地表？晶体在什么压力和温度下成核和生长？关于岩石行星上的地下岩浆系统和火山喷发方式，水晶记录能告诉我们什么？该项目将利用为陆地岩浆校准的矿物熔融温度气压计的最新进展，开发专门针对贫钠岩浆成分和与月球和灶神星等岩石小行星有关的高度还原条件校准的新的单斜辉石熔融和橄榄石熔融温度气压计。然后，我们将把这些新方法应用于阿波罗宇航员采集的月球熔岩套装，以获得对月球岩浆系统结构的新见解。

The Moon preserves a remarkable record of volcanism on a small rocky terrestrial planet. Lunar lavas were mainly erupted between ~4.35 and 3 billion years ago, with some areas of the Moon being volcanically active as recently as a billion years ago. The lunar lavas were sourced by partial melts from different regions of the lunar mantle, giving rise to a range of geochemical affiliations and crystallization histories. Different lunar magma compositions are thought to have reached the lunar surface via different storage and crystallization pathways, but the pressures and temperatures of magma storage and crystallization are not well known. The aim of this project is therefore to develop new mineral-melt thermobaromers in order to investigate the record of magma storage and crystallization on the Moon. We seek to answer questions such as: Did the lunar magmas stall and crystallize in crustal mush chambers, or did they ascend rapidly from the melting region to the surface? At what pressures and temperatures did crystals nucleate and grow? What can crystal records tell us about subsurface magmatic systems and volcanic eruption styles on rocky planets? The project will exploit recent advances in mineral-melt thermobarometers calibrated for terrestrial magmas to develop new clinopyroxene-melt and olivine-melt thermobarometers that are specifically calibrated for the Na-poor magma compositions and highly reducing conditions relevant to the Moon and rocky asteroids such as Vesta. We will then apply these new methods to suites of lunar lavas sampled by the Apollo astronauts to gain new insights into the architecture of lunar magmatic systems.