近日，美国地质调查局Kathryn E. Watts团队研究了黄石公园早期热点火山口岩浆中的锂矿。2025年4月16日出版的《地质学》杂志发表了这项成果。

可再生能源技术依赖于提取历史上需求量不高的金属，如锂（Li），对其矿床模型尚不完全了解。世界上最大的锂矿床之一位于16.4 Ma McDermitt火山口的湖泊沉积物中，该火山口形成于美国西部黄石热点火山活动的早期阶段。Li的喷发和后喷发活动是阐明矿床形成的主要挑战。石英晶体中保存的熔融包裹体提供了一种评估喷发前岩浆锂含量的方法。通过离子微探针测定的McDermitt流纹岩熔岩中熔融包裹体的Li浓度为400−1350 ppm，而基质流纹岩玻璃中的Li浓度则为20−70 ppm。

另外八个火山口的熔融包裹体数据合成表明，黄石热点轨道西部存在富锂流纹岩岩浆（200-2000ppm锂）的复发。然而，与可能影响锂保留的具有重叠断层网络的多环火山口复合体不同，McDermitt火山口在其整个演化过程中仍然是一个封闭的水文系统。建模表明，100立方千米的复活岩浆可以在岩浆流体中产生25-1.5亿吨锂，并支持富锂岩浆流体在封闭的内陆湖中聚集，然后在粘土矿物中蒸发浓缩和封存锂，从而形成McDermitt矿床。

附：英文原文

Title: Lithium from magma to mine in an early Yellowstone hotspot caldera

Author: Kathryn E. Watts

Issue&Volume: 2025-04-16

Abstract: Renewable energy technologies rely on the extraction of metals not historically in high demand, such as lithium (Li), for which ore deposit models are incompletely understood. One of the world’s largest Li deposits is hosted in lake sediments of the 16.4 Ma McDermitt caldera, which formed during the early stages of Yellowstone hotspot volcanism in the western United States. Eruptive and posteruptive mobility of Li are major challenges in elucidating deposit formation. Melt inclusions preserved in quartz crystals provide a means to assess pre-eruptive magmatic Li contents. Concentrations of Li determined by ion microprobe for melt inclusions in a McDermitt rhyolite lava are 4001350 ppm, compared to 2070 ppm Li in matrix rhyolite glasses. Synthesis with melt inclusion data for eight additional calderas demonstrates a recurrence of Li-rich rhyolitic magmas (2002000 ppm Li) in the western part of the Yellowstone hotspot track. However, unlike the multicyclic caldera complexes with overlapping fault networks that may have compromised Li retention, the McDermitt caldera remained a closed hydrologic system throughout its evolution. Modeling indicates 100 km3 of resurgent magma could yield 25150 Mt Li in a magmatic fluid and supports accumulation of Li-rich magmatic fluid in a closed intracaldera lake, followed by evaporative concentration and sequestration of Li within clay minerals to generate the McDermitt deposit.

DOI: 10.1130/G53140.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53140.1/653672/Lithium-from-magma-to-mine-in-an-early-Yellowstone