With substantial postglacial rhyolite eruptions and ongoing rapid uplift, the Laguna del Maule volcanic field in the southern Andes provides an exceptional opportunity to study the dynamics of an active silicic magmatic system. Using 4,093 P arrivals from 137 distant earthquakes recorded by 44 local stations over ∼2.25 years, we conduct teleseismic tomography to image the crustal structure down to 40 km below the volcanic field. A prominent low‐velocity body at depths between ∼0 and 12 km below sea level (b.s.l.), characterized by a volume of ∼500 km³ and a peak anomaly of −400 m/s (∼9%), overlaps the location of the upper‐crustal magma reservoir detected in recent gravity and surface wave tomography studies. Its estimated average P wave velocity of ∼4.6 km/s corresponds to an average melt fraction of about 14% and a melt volume of ∼70 km³. Petrologic observations are also consistent with generation and storage of rhyolitic melts at depths corresponding to the anomalous zone. Moreover, the tomographic results support a lower crust zone of MASH (melting, assimilation, storage, and homogenization) from a depth of ∼25 km to the base of the model, which likely reflects a deep crustal source of magma that contributes to and incubates the shallow silicic reservoir.

中文翻译：

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智利拉古纳德尔莫勒火山场的远震层析成像

随着大量冰期后流纹岩的爆发和持续的快速隆升，安第斯山脉南部的拉古纳德尔莫勒火山场为研究活跃的硅质岩浆系统的动力学提供了绝佳的机会。我们利用来自44个本地电台在约2. 25年内记录的137个遥远地震的4,093 P来信，进行了远程地震层析成像，以成像到火山场以下40 km处的地壳结构。一个突出的低速体在之间的深度〜 0和海平面以下（BSL）12公里，其特征在于体积〜 500公里³和异常的峰- 400米/秒（〜9％），与最近重力和面波层析成像研究中检测到的上地壳岩浆储集层位置重叠。其估计的平均P波速度约为4.6 km / s，相当于平均熔体分数约为14％，熔体体积约为70 km ³。岩石学观测也与流变质熔体在对应于异常区的深度处的生成和储存相一致。此外，层析成像结果支持了从约25 km深度到模型底部的MASH较低的地壳区域（熔融，同化，储存和均质化），这很可能反映了一个深部的岩浆源，它有助于并孵化。浅硅质储层。