Crystal and melt inclusion timescales reveal the evolution of magma migration before eruption.
Crystal and melt inclusion timescales reveal the evolution of magma migration before eruption.
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晶体和熔体包裹体的时间尺度揭示了火山喷发前岩浆运移的演化过程。
DOI：
10.1038/s41467-018-05086-8
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发表时间：
2018-07-09
影响因子：
16.6
通讯作者：
Calder ES
中科院分区：
文献类型：
--
作者：
Ruth DCS;Costa F;Bouvet de Maisonneuve C;Franco L;Cortés JA;Calder ES
熔融包裹体中挥发性元素的含量是了解岩浆迁移和脱气过程的重要工具，但其原始值可能会受到不同再平衡过程的影响。此外，含包裹体的晶体可能具有广泛的起源和年龄，进一步使岩浆过程的解释复杂化。为了澄清其中的一些问题，在这里，我们结合橄榄石扩散测时和熔体包裹体数据从2008年爆发的Llaima火山（智利）。我们发现，岩浆侵入发生在喷发前约4年，最小深度约为8公里。岩浆的运移和反应随时间的推移而变浅，在喷发前6个月左右，岩浆达到3- 4km的深度。这可能与报告的地震活动和火山灰排放有关。虽然一些解释仍然存在歧义，晶体分区和熔融包裹体的研究，使岩浆上升，脱气和火山监测数据的更完整的理解。熔融包裹体中的挥发分含量可以用来解释岩浆的运移和脱气过程。在这里，作者使用2008年Llaima喷发的橄榄石测时和熔融包裹体数据，发现岩浆侵入发生在喷发前4年，并在喷发前6个月达到3-4 km的深度。
Volatile element concentrations measured in melt inclusions are a key tool used to understand magma migration and degassing, although their original values may be affected by different re-equilibration processes. Additionally, the inclusion-bearing crystals can have a wide range of origins and ages, further complicating the interpretation of magmatic processes. To clarify some of these issues, here we combined olivine diffusion chronometry and melt inclusion data from the 2008 eruption of Llaima volcano (Chile). We found that magma intrusion occurred about 4 years before the eruption at a minimum depth of approximately 8 km. Magma migration and reaction became shallower with time, and about 6 months before the eruption magma reached 3–4 km depth. This can be linked to reported seismicity and ash emissions. Although some ambiguities of interpretation still remain, crystal zoning and melt inclusion studies allow a more complete understanding of magma ascent, degassing, and volcano monitoring data. Volatile contents in melt inclusions can be used to unravel magma migration and degassing. Here, the authors use olivine chronometry and melt inclusion data from the 2008 Llaima eruption and find that magma intrusion occurred 4 years before the eruption and reached a depth of 3–4 km, 6 months before the eruption.