Timescales of shock processes in martian meteorites

火星陨石冲击过程的时间尺度

• 批准号: 402260-2011
• 负责人: Walton, Erin
• 金额: $ 1.68万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=487997
• 关键词: Timescales; shock; processes; martian; meteorites

There are currently 55 Martian meteorites in the world's collection. These meteorites were ejected into space by high-velocity collisions (impacts) of asteroids or comets with the surface of Mars, accelerating rocks to velocities >5 km/s. The extreme physical conditions produced during the impact events cause unique features in the target rocks, called shock metamorphic effects. My research focuses on reading the history of the meteorites from the minerals and textures produced by shock metamorphism, revealing important clues about how material is exchanged between planets. In particular, high temperatures and pressures cause small pockets of the rock to become molten, called shock melt pockets. Minerals crystallize as these melts cool from high temperatures. Large amounts of Martian atmosphere are also found in the shock melt pockets, as this component is forced into the rock during impact.

目前全世界共有55颗火星陨石。这些陨石是由小行星或彗星与火星表面的高速碰撞（撞击）而被抛射到太空中，将岩石的速度加速到每秒50公里左右。在冲击事件中产生的极端物理条件在目标岩石中造成独特的特征，称为冲击变质效应。我的研究重点是从激波变质作用产生的矿物和纹理中解读陨石的历史，揭示行星之间物质交换的重要线索。特别是，高温和高压会导致岩石的小口袋变成熔融的，称为冲击融化袋。当这些熔体在高温下冷却时，矿物结晶。在激波熔体中也发现了大量的火星大气，因为这种成分在撞击过程中被迫进入岩石。