The Quaternary volcanic fields of the Eifel (Rhineland‐Palatinate, Germany) had their last eruptions less than 13,000 years ago. Recently, deep low‐frequency (DLF) earthquakes were detected beneath one of the volcanic fields showing evidence of ongoing magmatic activity in the lower crust and upper mantle. In this work, seismic wide‐ and steep‐angle experiments from 1978/1979 and 1987/1988 are compiled, partially reprocessed and interpreted, together with other data to better determine the location, size, shape, and state of magmatic reservoirs in the Eifel region near the crust‐mantle boundary. We discuss seismic evidence for a low‐velocity gradient layer from 30–36 km depth, which has developed over a large region under all Quaternary volcanic fields of the Rhenish Massif and can be explained by the presence of partial melts. We show that the DLF earthquakes connect the postulated upper mantle reservoir with the upper crust at a depth of about 8 km, directly below one of the youngest phonolitic volcanic centers in the Eifel, where CO₂ originating from the mantle is massively outgassing. A bright spot in the West Eifel between 6 and 10 km depth represents a Tertiary magma reservoir and is seen as a model for a differentiated reservoir beneath the young phonolitic center today. We find that the distribution of volcanic fields is controlled by the Variscan lithospheric structures and terrane boundaries as a whole, which is reflected by an offset of the Moho depth, a wedge‐shaped transparent zone in the lower crust and the system of thrusts over about 120 km length.

中文翻译：

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德国埃菲尔山下新生代火山场深地壳岩浆系统的地震学和地球物理特征

埃菲尔第四纪火山区（德国莱茵兰-普法尔茨州）的最后一次喷发发生在不到13,000年前。最近，在一个火山场下发现了深低频地震（DLF），显示下地壳和上地幔正在进行岩浆活动。在这项工作中，对1978/1979年和1987/1988年的地震广角和陡角实验进行了编辑，部分重新处理和解释，以及其他数据，以便更好地确定埃菲尔岩浆储层的位置，大小，形状和状态地幔边界附近的区域。我们讨论了深度为30-36 km的低速梯度层的地震证据，该层已经在Rhenish断层的所有第四纪火山岩田下的较大区域内发育，可以用部分熔融物的存在来解释。来自地幔的₂大量放气。西埃菲尔山深在6至10公里之间的亮点代表着第三纪岩浆储层，并被视为当今年轻音系中心下方的一个差异化储层的模型。我们发现火山场的分布受瓦里斯坎岩石圈结构和整个地层边界的控制，这反映为莫霍深度的偏移，下地壳中的楔形透明区域以及上空的逆冲系统。长度120公里。