Melt and gas transfer processes are essential to the formation and growth of the Earth’s crust and for sustaining volcanic activity. These processes also play a major role in magma fractionation at shallow depths (<10 km) where magmas stall rheologically and solidify. In this scenario, the conditions of melt and gas mobilization during progressive cooling of crystal mushes down to their solidus remain poorly understood. We present experimental data (at 1.1 kbar) showing how a combination of temperature and crystal content control the ability of melt and gas to escape from cooling and solidifying hydrous silicic magmas with initial crystal volume fractions (Φ) of 0.6, 0.7, and 0.8, and for temperature snapshots of 850, 800, and 750°. Microstructural observations and chemical data show that the amount of extracted melt increases by 70% from 850 to 750° and by 40% from Φ = 0.6 to 0.8 at 750°, due to the formation of interconnected crystal frameworks, gas expansion in constricted pore space, and filter pressing during cooling. As a result, our experiments suggest that melt and gas extraction from cooling mushes increases in proximity to their solidus and can operate efficiently at 0.6 < Φ <0.93. These observations shed light on maximum estimates of the segregation of gas-rich, crystal-poor magmas (0.02 m/year at 850° to 9 m/year at 750°) to form felsic dykes or eruptible systems feeding volcanoes.

熔体和气体的传输过程对于地壳的形成和生长以及维持火山活动至关重要。这些过程在岩浆流变失速并固化的浅层（<10 km）岩浆分离中也起着重要作用。在这种情况下，人们对晶体麝香逐渐冷却至固相线的过程中的熔体和气体动员条件仍然知之甚少。我们提供的实验数据（在1.1 kbar压力下）显示出温度和晶体含量的组合如何控制熔体和气体逃逸冷却和凝固含水硅质岩浆的能力，初始晶体体积分数（Φ）为0.6、0.7和0.8，以及850、800和750°的温度快照。显微组织观察和化学数据表明，在750°时，从850°C到750°，熔体的提取量增加了70％；从Φ= 0.6到0.8°，熔体的提取量增加了40％，这是由于形成了相互连接的晶体骨架，在狭窄的孔空间中气体膨胀，并在冷却期间压滤。结果，我们的实验表明，从冷却的麝香中提取的熔体和气体在其固相线附近增加，并且可以在0.6 <Φ<0.93的效率下有效地运行。这些观察结果为形成气体富集，晶体贫乏的岩浆（850°时为0.02 m /年，在750°时为9 m /年）的分离估计提供了最大的估计，从而形成了长石堤或火山爆发的系统。并在冷却过程中压滤。结果，我们的实验表明，从冷却的麝香中提取的熔体和气体在其固相线附近增加，并且可以在0.6 <Φ<0.93的效率下有效地运行。这些观察结果为形成气体富集，晶体贫乏的岩浆（850°时为0.02 m /年，在750°时为9 m /年）的分离估计提供了最大的估计，从而形成了长石堤或火山爆发的系统。并在冷却过程中压滤。结果，我们的实验表明，从冷却的麝香中提取的熔体和气体在其固相线附近增加，并且可以在0.6 <Φ<0.93的效率下有效地运行。这些观察结果为形成气体富集，晶体贫乏的岩浆（850°时为0.02 m /年，在750°时为9 m /年）的分离估计提供了最大的估计，从而形成了长石堤或火山爆发的系统。