近日，中国科学院地质与地球物理研究所吴福元团队报道了深成钾长石中钛的扩散揭示了超火山岩浆的长期储存。这一研究成果发表在2026年3月24日出版的《地质学》杂志上。

超级喷发（喷发体积超过450立方千米）是地球上最极端的火山事件之一。尽管其喷发阶段短暂（数天至数年），但硅质岩浆储库的积累与储存却可跨越数百万年。这些储库通常以富晶体的糊状体形式存在，可能通过热活化作用维持长期的喷发潜力。然而，对其存续时间的直接约束（尤其是来自侵入岩记录的约束）依然匮乏，这限制了学界评估长期火山灾害的能力。

研究组通过对与青藏高原南部庞多超级喷发相关的早始新世石英二长岩中的钾长石巨晶进行钛（Ti）扩散模拟，限定了硅质岩浆储库的最小寿命。X射线荧光图谱与微量元素分析揭示了反向钛环带，指示了镁铁质岩浆的补给。扩散年代学将最终喷发前岩浆补给与储库固结之间的时间间隔限定在>10万至100万年。

热模拟表明，补给引发的再加热可在同等时间尺度内维持上地壳岩浆温度（>800°C）。这些发现从深成岩角度提供了直接证据，表明接近喷发状态的硅质储库可存续数十万年，从而将短期火山信号与侵入岩记录所推断的长期储存联系起来。

附：英文原文

Title: Prolonged storage of supervolcanic magma revealed by titanium diffusion in plutonic K-feldspar

Author: Hou-Bin Chen, Wei-Qiang Ji, Shao-Hua Zhang, Fu-Yuan Wu

Issue&Volume: 2026-03-24

Abstract: Supereruptions, which discharge >450km3 of magma, are among Earth’s most extreme volcanic events. Although their eruptive phases are brief (days to years), the buildup and storage of silicic magma reservoirs can span millions of years. These reservoirs typically exist as crystal-rich mushes that may be thermally reactivated, sustaining long-term eruption potential. However, direct constraints on their longevity, especially from intrusive records, remain scarce, limiting our ability to assess the long-term volcanic hazards. Here, we constrain the minimum lifespan of a silicic magma reservoir by modeling titanium (Ti) diffusion in K-feldspar megacrysts from early Eocene quartz monzonites linked to the Pangduo supereruption in the southern Tibetan Plateau. X-ray fluorescence mapping and trace element analyses reveal reverse Ti zoning indicative of mafic recharge. Diffusion chronometry constrains the interval between the final pre-eruptive recharge and reservoir solidification to >1001000 k.y. Thermal modeling demonstrates that recharge-induced reheating can maintain upper-crustal magma temperatures (>800 °C) over comparable durations. These findings provide direct evidence from plutonic rocks that near-eruption silicic reservoirs can persist for hundreds of thousands of years, thereby bridging short-term volcanic signals with long-term storage inferred from intrusive records.

DOI: 10.1130/G54166.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G54166.1/727841/Prolonged-storage-of-supervolcanic-magma-revealed