Mineral records of magma storage and crystallization on the Moon

月球上保存着一颗小岩石类地行星上的火山活动的显著记录。月球熔岩主要是在43.5亿到30亿年前爆发的，月球的一些地区在10亿年前还处于火山活动状态。月球熔岩来源于月幔不同区域的部分熔体，从而产生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为人所知。因此，该项目的目的是开发新的矿物熔体温度计，以研究月球上岩浆储存和结晶的记录。我们试图回答这样的问题：月球岩浆是在地壳岩浆室中停滞并结晶，还是从融化区迅速上升到地表？晶体在什么压力和温度下形成和生长？关于岩石行星上的地下岩浆系统和火山喷发方式，晶体记录能告诉我们什么？该项目将利用针对陆地岩浆校准的矿物熔体热气压计的最新进展，开发新的斜辉石熔体和橄榄石熔体热气压计，这些热气压计专门针对与月球和灶神星等岩石小行星相关的na -贫岩浆成分和高度还原条件进行校准。然后，我们将把这些新方法应用于阿波罗宇航员取样的月球熔岩套件，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.