近日，法国奥尔良地质和矿产研究局Pierre Wawrzyniak团队报道了马约特岛下富熔体岩浆储层的大地电磁证据。相关论文于2025年10月29日发表在《自然》杂志上。

地壳岩浆储库的真实性质难以确知，因其无法原位采样。传统认为岩浆房主要包含熔融物质的观点，近来已被全地壳岩浆系统模型所取代——该模型认为储库主要由不活动的岩浆晶体构成，其中仅含少量流动性更强的熔体，形成"岩浆晶粥"。当相当比例的熔体在晶粥储库中分离形成富熔体透镜体时，便可能引发火山喷发。然而，全地壳岩浆系统模型本质上是一个默认方案，其立论依据主要是缺乏富熔体岩浆房的明确地球物理证据，以及基于喷发产物地球化学和结构分析对地壳储集区熔体比例所做的零星初步估算。

研究组通过对马约特岛熔岩电导率的实验室测量，将海平面下23±1公里处发现的高导异常体解释为岩浆储库。该大型岩浆储库（体积超过200立方千米）具有高熔体比例（22%-42%）。这种晶液比与重建的差异化路径相吻合，该路径产生了近期在马约特岛喷发的熔岩。该储库可能与2018-2019年法尼马奥雷大型海底火山喷发的供给系统相连。

附：英文原文

Title: Magnetotelluric evidence for a melt-rich magmatic reservoir beneath Mayotte

Author: Wawrzyniak, Pierre, Gaillard, Fabrice, Hautot, Sophie, Andujar, Juan, Tarits, Pascal, Arbaret, Laurent, Guegan, Samuel, Sifr, David, DEu, Jean-Franois, Deparis, Jacques, Lemoine, Anne, Thinon, Isabelle, Warden, Sheldon, Dubois, Frdric

Issue&Volume: 2025-10-29

Abstract: The exact nature of crustal magmatic reservoirs is elusive as they cannot be sampled in situ. The traditional view that magma chambers contain essentially molten material has recently been replaced by the transcrustal magmatic system (TCMS), in which reservoirs are mostly composed of immobile magmatic crystals with a minute fraction of more mobile melt1,2,3, creating a ‘magmatic mush’3. Eruptions are possible if a significant portion of melt segregates into melt-rich lenses within the mush reservoir1,2,3. The TCMS concept is, however, a default model essentially justified by the absence of clear geophysical signatures of melt-rich magma chambers1,4, and by the rare and tentative estimates of the melt fraction in the crustal storage zones based on geochemical and textural analysis of eruptive products5,6. Here we image a bright electrical conductor at 23±1km below sea level beneath Mayotte island that we interpret as a magmatic reservoir, based on laboratory measurements of Mayotte’s melt conductivity. This large magmatic reservoir (more than 200km3) contains a high melt fraction (22–42%). Such a crystal-to-liquid ratio matches the reconstructed differentiation paths7,8,9 producing the melts that recently erupted at Mayotte. This reservoir is possibly connected to the system that fed the large submarine eruption of Fani Maoré in 2018–201910.

DOI: 10.1038/s41586-025-09625-4

Source: https://www.nature.com/articles/s41586-025-09625-4