We use new estimates of the total content and speciation of volatiles released during the ascent and eruption of lunar mare basalt magma to model the generation and behavior of gas bubbles, the disruption of magma at shallow depth by bubble expansion, and the acceleration and dispersal of the resulting pyroclasts. Lunar eruptions in near-vacuum differ significantly from those on bodies with an atmosphere: 1) exposure to near-zero external pressure maximizes volatile release to form gas bubbles; 2) the infinite potential expansion of the gas bubbles both ensures and maximizes magma fragmentation into pyroclastic liquid droplets with sizes linked to the bubble size distribution; 3) the speeds to which gas and entrained pyroclasts can be accelerated by gas expansion are also maximized. Generation of CO gas bubbles at much greater depths and pressures than bubbles of other volatiles produces bimodal (~120 and 650 μm) total pyroclast size distributions. In the near-vacuum, gas expands to pressures so low that gas-particle interactions enter the Knudsen regime, resulting counter-intuitively in the median grainsize in pyroclastic deposits first increasing, then decreasing, and finally increasing again with increasing distance from the vent, instead of decreasing monotonically as when an atmosphere is present. These complex gas-particle interactions cause clast size distributions to vary in a complex way with distance from the vent and the maximum thickness of the deposit to occur at about 75% of the maximum pyroclast range. Lunar eruptions typically evolve through four stages, which significantly influence gas release patterns. Most volatiles are released during the second, hawaiian-style eruption stage. However, elevated gas concentration can occur both in the short first stage (due to gas accumulation in the dike tip during ascent from the mantle) and in the third and fourth stages (due to reduced volume flux, increased time for gas bubble formation, growth, rise and coalescence, and strombolian activity replacing the hawaiian eruption style). Such gas concentration mechanisms can increase pyroclast ranges by a factor of ~5, but result in very much thinner deposits than if no concentration occurs. Maximum pyroclast range scales essentially linearly with total mass fraction of released volatiles; thus determination of the deposit radius around specific vents can provide data on lunar magma volatile contents. If the volatile inventory of the Apollo 17 orange glass bead picritic magma (~3400 ppm maximum) is typical, maximum ranges of the majority of pyroclasts would have been ~20 km. Such eruptions could explain 79% of the currently recognized pyroclastic deposits on the Moon. A few larger deposits and vents, such as the Aristarchus Plateau Dark Mantle and Cobra Head, suggest higher magma volatile contents. Numerous lunar vents show little evidence of associated pyroclastic deposits. Together, these observations suggest a wide range of volatile contents in lunar basaltic magma mantle source regions.

我们使用新的估算值来估算月球母岩玄武岩岩浆上升和喷发过程中释放的总挥发物的种类和形态，以模拟气泡的产生和行为，由于气泡膨胀在浅深度产生的岩浆破坏，以及气泡的加速和扩散。产生的破骨细胞。接近真空的月球爆发与有大气的月体爆发有很大不同：1）暴露于接近零的外部压力会使挥发物释放最大化，从而形成气泡；2）气泡的无限可能膨胀既确保并最大化了岩浆碎裂成火山碎屑液滴的大小，其大小与气泡的大小分布有关；3）气体和夹带的火山爆发可以通过气体膨胀而加速的速度也达到了最大。与其他挥发物的气泡相比，在更大深度和压力下生成CO气泡会产生双峰（〜120和650μm）的整体破火山体尺寸分布。在接近真空的情况下，气体膨胀至如此低的压力，以至于气体与颗粒之间的相互作用进入克努森状态，这与火成岩沉积物的中值粒径相反，导致结果逐渐增大，然后减小，最后随着与排气孔距离的增加而再次增大，而不是在存在大气时单调减少。这些复杂的气体-颗粒相互作用会导致碎片尺寸分布以复杂的方式随距通风口的距离而变化，并且沉积物的最大厚度将出现在最大火山碎屑范围的约75％处。月球爆发通常经历四个阶段，这会显着影响气体的释放方式。大多数挥发物在第二个夏威夷式喷发阶段释放。但是，在较短的第一阶段（由于从地幔上升期间堤坝尖端中的气体积聚）和第三和第四阶段（由于体积通量减少，气泡形成时间增加，生长）都会导致气体浓度升高。 ，上升和合并，以及斯特兰堡活动取代了夏威夷的喷发风格）。这样的气体浓缩机制可以使火山碎裂范围增加约5倍，但沉积物比没有浓缩时要薄得多。最大解热破损范围基本上与释放的挥发物的总质量分数成线性比例关系。因此，确定特定喷口周围的沉积半径可以提供有关月球岩浆挥发物含量的数据。如果典型的阿波罗17号橙色玻璃微珠苦味岩浆的挥发物含量（最大值约为3400 ppm），则大多数火山碎屑的最大射程将约为20 km。此类喷发可以解释目前在月球上发现的79％的火山碎屑沉积物。一些较大的沉积物和喷口，例如阿里斯塔丘斯高原暗幔和眼镜蛇头，表明岩浆挥发物含量较高。大量的月球孔几乎没有相关的火山碎屑沉积迹象。总之，这些观察结果表明，月球玄武岩浆地幔源区的挥发物含量范围很广。例如Aristarchus高原的暗幔和眼镜蛇头，表明岩浆挥发物含量较高。大量的月球孔几乎没有相关的火山碎屑沉积迹象。总之，这些观察结果表明，月球玄武岩浆地幔源区的挥发物含量范围很广。例如Aristarchus高原的暗幔和眼镜蛇头，表明岩浆挥发物含量较高。大量的月球孔几乎没有相关的火山碎屑沉积迹象。总之，这些观察结果表明，月球玄武岩浆地幔源区的挥发物含量范围很广。