论文标题
原球磁盘中主要元素化学的动态演化及其对软晶形成的影响
Dynamic evolution of major element chemistry in protoplanetary disks and its implications for chondrite formation
论文作者
论文摘要
软骨是地球的可能基础，并且确定最能代表地球的软骨群是解决早期地球状态的关键。然而，软骨的起源仍然存在争议，部分原因是它们令人困惑的主要元素组成，有些在AL，CA和MG中表现出耗竭。基于原活力磁盘的新热化学演化模型，我们表明具有类似于普通和enstatite软骨的耗尽模式的行星可以起源于1-2 au，而Enstatite蒸发的地方则可以源自。在Enstatite的“蒸发前线”周围，包括脚本岩在内的难治性矿物质的较大向内流动，卵石浓度很高，这些矿物质的损失导致Al，CA和MG耗尽。当蒸发的固体颗粒将卵石的浓度进一步增强时，可能会触发流媒体不稳定性。因此，具有普通和enstatite软骨的组成的行星可能是在陆地区域自然产生的。对于普通和enstatite软骨的潜在源区域内，易肽的优先损失也会增强Mg/Si和重型SI同位素。呈现这两个特征的地球可能源于普通和enstatite软骨的诞生的内部。
Chondrites are the likely building blocks of Earth, and identifying the group of chondrite that best represents Earth is a key to resolving the state of the early Earth. The origin of chondrites, however, remains controversial partly because of their puzzling major element compositions, some exhibiting depletion in Al, Ca, and Mg. Based on a new thermochemical evolution model of protoplanetary disks, we show that planetesimals with depletion patterns similar to ordinary and enstatite chondrites can originate at 1-2 AU just outside where enstatite evaporates. Around the "evaporation front" of enstatite, the large inward flow of refractory minerals, including forsterite, takes place with a high pebble concentration, and the loss of those minerals result in depletion in Al, Ca, and Mg. When evaporated solid grains re-condense onto pebbles, the concentration of pebbles is further enhanced, potentially triggering the streaming instability. Planetesimals with the composition of ordinary and enstatite chondrites can thus be naturally created in the terrestrial region. The preferential loss of forsterite also creates an enhancement of Mg/Si and heavy Si isotopes just inside the potential source region for ordinary and enstatite chondrites. Earth, which shows both features, may originate just inside where ordinary and enstatite chondrites were born.
