The Lower Imbrian is an era in the Hadean eon that lasted from 3.85bya to 3.8bya.  The lunar basins Crisium, Tranquilitatis, Serenitatis, Fecunditatis, and Procellarum were formed during this time period. 

Crisium Basin on the Moon

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.