Evidence that an ice-free corridor between two ice sheets developed when the continental ice first began tomelt came primarily from radiocarbon dating.
当大陆上的冰开始融化时，两块冰原之间形成了一条无冰走廊，这一证据主要来自放射性碳测年法。
3
Continued bombardments and internal pressures made the growing Earth hotter, causing its interior tomelt and the heavier elements to sink and form Earth's core.