1. Precambrian Era By Erich Hartman

2. When It Occurred The Precambrian Era occurred from 4.6 billion years ago to 544 million years ago. It was the first of four eras on the geological time scale.

3. The Precambrian Supereon The Precambrian Supereon Is divided into three Precambrian eons, the Proterozoic, the Archaean, and Hadean.

4. Proterozoic Eon  This eon refers to the time from the lower Cambrian boundary, 542 Ma (million), back through 2500 Ma.  The Proterozoic Eon is divided into three eras, the Neoproterozoic, Mesoproteozoic, and Paleoproterozoic.

5. Neoproterozoic Era This era is the upper geological era of the Proterozoic eon, from the Cambrian period lower boundary (542 Ma) back to 1000 Ma. This era is the upper geological era of the Proterozoic eon, from the Cambrian period lower boundary (542 Ma) back to 1000 Ma. The Neoproterozoic era corresponds to Precambrian Z rocks of older North American geology. The Neoproterozoic era corresponds to Precambrian Z rocks of older North American geology.

6. Edicaranian Period TTTThe Edicaranian period is the upper geological period of the Neoproterozoic era. DDDDuring this period the Edicaranian fauna appeared. IIIIt happened from 630 Ma to 542 Ma.

7. Cryogenian Period The Cryogenian period is the middle period in the Neoproterozoic era. It dated from 950 Ma to 630 Ma.

8. Tonian Period The Tonian period is the earliest period in the Neoproterozoic era. The Tonian period is the earliest period in the Neoproterozoic era. It dated from 1000 Ma to 950 Ma. It dated from 1000 Ma to 950 Ma.

9. Mesoproterozoic Era  The Mesoproterozoic Era is the middle era of the Proterozoic Eon.  It dated from 1000 Ma to 1600 Ma.  It corresponds to “Precambrian Y” rocks of older North American geology.

10. Paleoproterozoic Period The Paleoproterozoic period is the oldest period in the Neoproterozoic era. The Paleoproterozoic period is the oldest period in the Neoproterozoic era. It dates from 1600 Ma to 2500 Ma. It dates from 1600 Ma to 2500 Ma. It corresponds to “Precambrian X” rocks of older North American geology. It corresponds to “Precambrian X” rocks of older North American geology.

11. Archaean Eon Dated from 2500 Ma to 3800 Ma. Dated from 2500 Ma to 3800 Ma.

12. Hadean Eon This term was intended originally to cover the time before any preserved rocks were observed. This term was intended originally to cover the time before any preserved rocks were observed. Some zircon crystal from 4400 Ma demonstrated the existence of crust in the Hadean eon. Some zircon crystal from 4400 Ma demonstrated the existence of crust in the Hadean eon. Other records from Hadean time come from the moon and meteorites. Other records from Hadean time come from the moon and meteorites.

13. My One Source www.wikipedia.com www.wikipedia.com www.wikipedia.com