The lunar mare are radioactively dated at:
A)4.6 billion years old, forming first among the lunar features.
B)4.2-3.9 billion years old, comparable to the adjacent highlands.
C)3.9-3.2 billion years old, forming after most of the bombardment was over.
D)3.5-2.5 billion years old, similar to the formation of our own oceans.
E)less than a billion years old, the most recent additions to the Moon.

Question

Quizplus · Accepted Answer

The lunar mare are radioactively dated to be 3.9-3.2 billion years old, forming after most of the bombardment was over. The lunar mare are radioactively dated at 3.9-3.2 billion years old, forming after most of the bombardment was over. This is supported by the fact that they contain fewer impact craters than the surrounding highlands which suggests that they formed after the period of heavy bombardment had ended.

The Lunar Mare Are Radioactively Dated At