Development of an experimental technique for characterizing the effects of magma flow in porous media

火山喷发出的绝大多数岩浆最初是在地幔(地壳下的物质)中产生的，需要经过数百英里才能到达地表，成为可以收集的火山岩。然后，地球化学家和岩石学家利用火山岩来更好地了解地球内部发生的地质过程。在其旅程中，岩浆将不可避免地通过与它们所经过的坚固地幔的相互作用而经历许多修改，模糊了火山岩和深处来源之间的联系。这项研究的主要目的是开发一种新的实验技术来模拟岩浆在地幔中的迁移，并更好地量化其迁移对岩浆化学和物理特征的影响。实验产品将被与天然火山岩进行比较，并将被用来了解深层熔融过程与地球表面火山作用之间的关系。实验将在一个大气层的熔炉中进行。这项初步研究将研究硅酸盐熔体如何在开放系统中流过多孔固体基质，并系统地改变该系统的物理(熔体流量、渗透率、孔隙度)和化学(熔体组成、多孔岩石基质的矿物组合)性质。实验产品将用电子探针、LA-ICPMS、扫描电子显微镜和显微断层扫描进行表征。这一装置将为研究熔体输运动力学及其对熔体和主体材料组成的影响提供一种新的方法。该项目的主要目标是(1)量化岩浆流动和熔融-固体相互作用对大洋玄武岩中主要和微量元素浓度范围的影响，(2)确定保存原始岩浆中的源信号所需的条件，以及(3)表征岩浆流动对地幔岩石学的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The vast majority of magmas that erupt from volcanoes is originally produced in the mantle (material beneath the crust) and needs to travel up to hundreds of miles before reaching the surface and becoming a volcanic rock that can be collected. Volcanic rocks are then used by geochemists and petrologists to better understand geologic processes happening in the Earth's interior. During its journey, magmas will inevitably undergo many modifications through interaction with the solid mantle through which they travel, blurring the link between the volcanic rocks and the source at depth. The primary objective of this research is to develop a new experimental technique to simulate the migration of magmas through the mantle and better quantify the impact of thier migration on the chemical and physical characteristics of magmas. The experimental products will be compared to the natural volcanic rocks and will be used to understand the relation between melting processes at depths and volcanism at the surface of the Earth.Experiments will be performed in a one-atmosphere furnace. This pilot study will investigate how a silicate melt flows through a porous solid matrix in open-system, and to systematically vary the physical (melt flux, permeability, porosity) and chemical (melt composition, mineral assemblage of the porous rock matrix) properties of the system. Experimental products will be characterized by electron microprobe, LA-ICP-MS, SEM and microtomography. This setup will provide a novel approach to study both the dynamics of melt transport and its impact on the composition of the melt and the host material. The main objectives of this project are (1) the quantification of the effect of magma flow and melt-solid interaction on the range of major and trace element concentrations in oceanic basalts, (2) the determination of the required conditions for the preservation of the source signal in primary magmas, and (3) the characterization of the effect of magma flow on mantle lithologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.