The early martian evolution—Constraints from basin formation ages
The early martian evolution—Constraints from basin formation ages
复制标题
DOI：
10.1016/j.icarus.2007.12.008
复制
发表时间：
2008-05
期刊：
影响因子：
3.2
通讯作者：
S. Werner
中科院分区：
文献类型：
--
作者：
S. Werner
撞击盆地的形成年龄可以让我们了解行星的早期演化。火星海盆Hellas、Isidis和Argyre提供了一个重要的时间标志，说明磁发电机的停止和地壳厚度的分布，这两者都是在4Ga前建立的。根据陨石坑的统计，没有火星表面的年龄超过4.15 Ga，而且都比最古老的月球表面年轻。我表明，月球和火星上的重轰击时期演变相似，但内生过程已经删除了最古老的火星盆地记录。形成盆地的抛射体人口似乎与今天在内太阳系中观察到的撞击物人口不同。目前还不确定重轰击时期是灾难性的还是以行星形成的衰减通量为特征。
Impact basin formation ages give insight into the early evolution of a planet. The martian basins Hellas, Isidis and Argyre provide an important time-marker for the cessation of the magnetic dynamo and the crustal thickness distribution, both established before 4 Ga ago. No martian surfaces are older than 4.15 Ga based on crater count statistics, and all are younger than the oldest lunar ones. I show that the heavy bombardment period on the Moon and Mars evolved similarly, but endogenic processes have removed the oldest martian basin record. The basin-forming projectile population appears to be different from the impactor population observed today in the inner Solar System. It is yet uncertain whether the heavy bombardment period is cataclysmic or characterized by the decaying flux of planetary formation.