<em>The focus is the place inside Earth's crust where an earthquake originates. The point on the Earth's surface directly above the focus is the epicenter.</em>
The Proterozoic Eon continued for about 2,500 to 541 mn years ago and it preceded the Archean. Consisting of the deepwater deposits and the strata, and showed a rapid continental acceleration and the occurrence of the first known glaciations also to place.
The paleozoic eon was for about 542 to 251mn years ago and it was divided into the six geological period ad they started after the breakup of the supercontinent as Pangea.
The archean eon is an eon that was for about4,000 to 2,500 mn years ago with a tectonic layer of rocks and rocks were more active than they are now. Formation of the mudstone and the volcanic sediments.
The Mesozoic era was about 252 to 66 mn years ago and it was the age of reptiles and the coniferous, as Mesozoic is the middle life and is one of the three eras of the Phanerozoic eon.
Cenozoic is a new life and is the most recent phase of the geologic eras. ad extends from about 66 mn yer ago. Known as the extinction event of the earth.
Hadean eon stared with the formation of the earth 4.6 billion years ago.
