Thermal Evolution of the Impact‐Induced Cryomagma Chamber Beneath Occator Crater on Ceres
Thermal Evolution of the Impact‐Induced Cryomagma Chamber Beneath Occator Crater on Ceres
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DOI：
10.1029/2018gl080327
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发表时间：
2019-02
影响因子：
5.2
通讯作者：
M. Hesse;J. Castillo‐Rogez
中科院分区：
文献类型：
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作者：
M. Hesse;J. Castillo‐Rogez
矮行星谷神星上的奥卡托陨石坑中的光斑是盐的积累，被解释为冰火山的产物。目前根据陨石坑计数得出的年龄估计表明，陨石坑形成的撞击与陨石坑中心和最近区域Cerealia Facula的形成之间的最大差异为18 Ma。在这里，我们模拟了Occator陨石坑下方潜在的撞击诱发低温岩浆室的热演化，并表明它在不到12 Ma的时间内冷却。为了达到18 Ma的冷却时间，需要超过11，000 km3的初始熔体体积。然而，模拟表明，较小的初始低温岩浆室可能导致下地壳的部分熔融。这可能允许位于谷神星多孔上地幔的深层盐水对岩浆房进行补给，并可能延长冰火山活动的寿命。
The faculae in Occator Crater on dwarf planet Ceres are an accumulation of salts that have been interpreted as cryovolcanic products. Current age estimates from crater counting suggest a maximum 18‐Ma difference between the crater forming impact and the formation of Cerealia Facula, the central and most recent region in the crater. Here we model the thermal evolution of the potential impact‐induced cryomagma chamber beneath Occator Crater and show that it cools in less than 12 Ma. To reach cooling times of 18 Ma requires initial melt volumes exceeding 11,000 km3. However, simulations suggest that smaller initial cryomagma chambers may lead to partial melting of the lower crust. This may allow recharge of the magma chamber by deep brines located in the porous upper mantle of Ceres and may extend the longevity of cryovolcanic activity.