The Role of Water in Precambrian Ultramafic Magmatism: Insights from an In-Situ Microbeam and Nanobeam Assessment of Hydromagmatic Amphibole

澳大利亚、加拿大和俄罗斯的一些前寒武纪(&gt；6亿年前)科马提岩和其他超镁铁质岩石中的热液岩浆角闪石表明，母岩浆中有&gt；3%的水。这些岩浆水的来源可能是地壳或地幔。对水源的限制将深刻影响前寒武纪地壳演化和水循环的概念。该项目的最终目标是通过对角闪石的原位微束和纳束分析，为地质和化学上不同类型的前寒武纪超镁铁质岩石提供一个综合的微量元素和同位素数据集，从而限制水在早期地球岩浆活动中的作用。

Hydromagmatic amphibole in some Precambrian (>600 million years old) komatiites and other ultramafic rocks in Australia, Canada and Russia indicates >3% water in the parental magmas. This magmatic water could be crustal or mantle in origin. Constraints on the water source would profoundly impact concepts of Precambrian crustal evolution and water recycling. The ultimate goal of this project is to provide constraints on the role of water in early Earth magmatism, through in situ microbeam and nanobeam analysis of the amphibole to produce an integrated trace element and isotopic dataset for geologically and chemically diverse types of Precambrian ultramafic rocks.