Unravelling the generation of compositionally and thermally zoned magma reservoirs is important to our understanding of the dynamic processes operating in magmatic systems. Here, we present new major and trace element data for volcanic glasses from the classically zoned Laacher See Tephra and suggest that mafic recharge may play an important role in producing the observed compositional gradient. Mafic phonolite glass from the upper part of the Laacher See Tephra records the addition of ca. 30% basanite magma, which is recognised by an increase in REE + Y and a decrease in Th, U and Zr relative to glasses from more evolved units. We suggest that the Laacher See magmatic system was sustained by repeated episodes of basanite recharge and calculate a recharge magma flux of between 2 × 10 –5 and 1 × 10 −4 km 3 y −1 in the 20 kyr leading up to the eruption. Basanite addition would have provided heat required to generate the strong compositional and thermal gradients that are recorded in crystals ejected during the Laacher See Tephra eruption.

中文翻译：

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Laacher See 岩浆系统中的化学分带和开放系统过程

解开成分和热分区岩浆储层的产生对于我们理解岩浆系统中运行的动态过程很重要。在这里，我们提供了来自经典分区 Laacher See Tephra 的火山玻璃的新的主要和微量元素数据，并表明镁铁质补给可能在产生观察到的成分梯度方面发挥重要作用。来自 Laacher See Tephra 上部的镁铁质音韵玻璃记录了大约 . 30% 的玄武岩岩浆，相对于来自更进化单元的玻璃，可以通过 REE + Y 的增加和 Th、U 和 Zr 的减少来识别。我们认为 Laacher See 岩浆系统是由巴桑岩的反复补给维持的，并计算出在 20 kyr 喷发前的 2 × 10 –5 和 1 × 10 -4 km 3 y -1 之间的补给岩浆通量。巴桑石的添加会提供产生强烈的成分和热梯度所需的热量，这些梯度记录在 Laacher See Tephra 喷发期间喷出的晶体中。