A time series of experiments at high temperature have been performed to investigate the influence of particle settling on magma mixing. A natural rhyolite glass was held above a natural basalt glass in a platinum crucible. After melting of the glasses at superliquidus temperatures, a platinum sphere was placed on the upper surface of the rhyolitic melt and sank into the experimental column (rhyolitic melt above basaltic melt). Upon falling through the rhyolitic–basaltic melt interface, the Pt sphere entrained a filament of rhyolitic melt in its further fall. The quenched products of the experiments were imaged using X-ray microCT methods. The images of our time series of experiments document the formation of a rhyolite filament as it is entrained into the underlying basalt by the falling platinum sphere. When the Pt particle reached the bottom of the crucible, the entrained rhyolitic filament started to ascend buoyantly up to the initial rhyolitic–basaltic interface. This generated a significant thickness increase of a comingled “melange” layer at the interface due to “liquid rope coiling” and piling up of the filament. As a consequence, the basalt/rhyolite interface was greatly enlarged and diffusive hybridisation greatly accelerated. Further, bubbles, originating at the interface, are observed to have risen into the overlying rhyolite dragging basalt filaments with them. Upon crossing the basalt/rhyolite interface, the bubbles have non-spherical shapes as they adapt to the differing surface tensions of basaltic and rhyolitic melts. Major element profiles, measured across the rhyolite filaments, exhibit asymmetrical shapes from the rhyolite into the basalt. Na and Ti reveal uphill diffusion from the rhyolite towards the interface in the filament cross sections. These results reveal the potential qualitative complexity of the mingling process between rhyolitic and basaltic magmas in the presence of sinking crystals. They imply that crystal-rich magma mingling may be expected to be accelerated with respect to crystal-poor systems. We urge the further fluid dynamic analysis of these phenomena, obtainable for the first time using detailed tomographic imaging.

中文翻译：

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颗粒沉降引起的岩浆混合

已经在高温下进行了一系列时间实验，以研究颗粒沉降对岩浆混合的影响。将天然流纹岩玻璃置于铂坩埚中的天然玄武岩玻璃上方。在超液相线温度下玻璃熔化后，将铂球放置在流纹岩熔体的上表面并沉入实验柱中（流纹岩熔体在玄武岩熔体上方）。在通过流纹岩-玄武岩熔体界面下落时，Pt 球体在其进一步下落中夹带了一条流纹岩熔体细丝。使用 X 射线显微 CT 方法对实验的淬火产物进行成像。我们的时间序列实验图像记录了流纹岩细丝的形成，因为它被下落的铂球夹带到下面的玄武岩中。当 Pt 颗粒到达坩埚底部时，夹带的流纹质细丝开始浮力上升至初始流纹质-玄武质界面。由于“液体绳索缠绕”和长丝的堆积，这在界面处产生了混合“混杂”层的显着厚度增加。结果，玄武岩/流纹岩界面大大扩大，扩散杂交大大加速。此外，观察到起源于界面的气泡上升到上覆的流纹岩中，并拖着玄武岩细丝。在穿过玄武岩/流纹岩界面时，气泡具有非球形形状，因为它们适应玄武岩和流纹岩熔体的不同表面张力。主要元素分布，在流纹岩细丝上测量，从流纹岩到玄武岩呈现出不对称的形状。Na 和 Ti 揭示了从流纹岩向细丝横截面中的界面向上扩散。这些结果揭示了在下沉晶体存在下流纹质和玄武质岩浆之间混合过程的潜在定性复杂性。它们意味着，对于缺乏晶体的系统，富含晶体的岩浆混合可能会加速。我们敦促对这些现象进行进一步的流体动力学分析，这是首次使用详细的断层成像技术获得的。它们意味着，对于缺乏晶体的系统，富含晶体的岩浆混合可能会加速。我们敦促对这些现象进行进一步的流体动力学分析，这是首次使用详细的断层成像技术获得的。它们意味着，对于缺乏晶体的系统，富含晶体的岩浆混合可能会加速。我们敦促对这些现象进行进一步的流体动力学分析，这是首次使用详细的断层成像技术获得的。