The Role of Post‐Shock Heating by Plastic Deformation During Impact Devolatilization of Calcite (CaCO3)
The Role of Post‐Shock Heating by Plastic Deformation During Impact Devolatilization of Calcite (CaCO3)
复制标题
方解石 (CaCO3) 冲击脱挥发分过程中塑性变形引起的冲击后加热的作用
DOI：
10.1029/2020gl091130
复制
发表时间：
2021
影响因子：
5.2
通讯作者：
Okazaki Keishi
中科院分区：
文献类型：
--
作者：
Kurosawa Kosuke;Genda Hidenori;Azuma Shintaro;Okazaki Keishi
准确理解撞击条件与陨石冲击诱发热变质程度之间的关系，有助于了解早期太阳系的撞击环境。最近的一项氢代码显示，撞击加热比以前认为的要高得多。这是因为受冲击岩石的塑性变形在减压过程中引起进一步的加热，这被称为冲击后加热。在这里，我们将撞击模拟与方解石撞击脱挥发的实验室实验进行比较，以研究撞击后加热在自然样品中是否也很重要。我们根据热力学计算了方解石产生的二氧化碳的质量。我们发现iSALE可以再现方解石强度岩石的脱挥发行为。相比之下，较低岩石强度下co2的计算质量比实验值有系统的小。我们的结果要求对陨石热变质作用的解释进行重新评估。
An accurate understanding of the relationship between the impact conditions and the degree of shock‐induced thermal metamorphism in meteorites allows the impact environment in the early Solar System to be understood. A recent hydrocode has revealed that impact heating is much higher than previously thought. This is because plastic deformation of the shocked rocks causes further heating during decompression, which is termed post‐shock heating. Here we compare impact simulations with laboratory experiments on the impact devolatilization of calcite to investigate whether the post‐shock heating is also significant in natural samples. We calculated the mass of CO2produced from the calcite, based on thermodynamics. We found that iSALE can reproduce the devolatilization behavior for rocks with the strength of calcite. In contrast, the calculated masses of CO2at lower rock strengths are systematically smaller than the experimental values. Our results require a reassessment of the interpretation of thermal metamorphism in meteorites.