i am chinese you are offending my race, gender, and homeowkr skills
<span>An eon is a geologically around tens of millions of years. A period is a million year included in an eon which is also made up of several eras. Therefore my answer is a period due to it being a subset of an era which is a subset of an eon.</span>
<span>The oldest rocks are Early Proterozoic metamorphic rocks</span>
