precambrian era

Precambrian EraPrecambrian Era

By Erich HartmanBy Erich Hartman

When It OccurredWhen It Occurred The Precambrian Era occurred from 4.6 billion The Precambrian Era occurred from 4.6 billion

years ago to 544 million years ago.years ago to 544 million years ago. It was the first of four eras on the geological It was the first of four eras on the geological

time scale.time scale.

The Precambrian Supereon• The Precambrian Supereon Is

divided into three Precambrian eons, the Proterozoic, the Archaean, and Hadean.

Proterozoic EonProterozoic Eon This eon refers to the time from the lower This eon refers to the time from the lower

Cambrian boundary, 542 Ma (million), Cambrian boundary, 542 Ma (million), back through 2500 Ma.back through 2500 Ma.

The Proterozoic Eon is divided into three The Proterozoic Eon is divided into three eras, the Neoproterozoic, eras, the Neoproterozoic, Mesoproteozoic, and Paleoproterozoic.Mesoproteozoic, and Paleoproterozoic.

Neoproterozoic EraNeoproterozoic Era This era is the upper geological era This era is the upper geological era

of the Proterozoic eon, from the of the Proterozoic eon, from the Cambrian period lower boundary Cambrian period lower boundary (542 Ma) back to 1000 Ma.(542 Ma) back to 1000 Ma.

The Neoproterozoic era corresponds The Neoproterozoic era corresponds to Precambrian Z rocks of older North to Precambrian Z rocks of older North American geology.American geology.

Edicaranian PeriodEdicaranian Period

The Edicaranian period is the upper The Edicaranian period is the upper geological period of the Neoproterozoic geological period of the Neoproterozoic era.era.

During this period the Edicaranian fauna During this period the Edicaranian fauna appeared.appeared.

It happened from 630 Ma to 542 Ma.It happened from 630 Ma to 542 Ma.

Cryogenian Period

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

Tonian PeriodTonian PeriodThe Tonian period is the earliest The Tonian period is the earliest

period in the Neoproterozoic era.period in the Neoproterozoic era. It dated from 1000 Ma to 950 Ma.It dated from 1000 Ma to 950 Ma.

Mesoproterozoic EraMesoproterozoic Era

The Mesoproterozoic Era is the middle era The Mesoproterozoic Era is the middle era of the Proterozoic Eon.of the Proterozoic Eon.

It dated from 1000 Ma to 1600 Ma.It dated from 1000 Ma to 1600 Ma. It corresponds to “Precambrian Y” rocks of It corresponds to “Precambrian Y” rocks of

older North American geology.older North American geology.

Paleoproterozoic PeriodPaleoproterozoic Period The Paleoproterozoic period is the The Paleoproterozoic period is the

oldest period in the Neoproterozoic oldest period in the Neoproterozoic era.era.

It dates from 1600 Ma to 2500 Ma.It dates from 1600 Ma to 2500 Ma. It corresponds to “Precambrian X” It corresponds to “Precambrian X”

rocks of older North American rocks of older North American geology. geology.

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

Hadean EonHadean Eon This term was intended originally to This term was intended originally to

cover the time before any preserved cover the time before any preserved rocks were observed.rocks were observed.

Some zircon crystal from 4400 Ma Some zircon crystal from 4400 Ma demonstrated the existence of crust demonstrated the existence of crust in the Hadean eon. in the Hadean eon.

Other records from Hadean time Other records from Hadean time come from the moon and meteorites.come from the moon and meteorites.

My One SourceMy One Source www.wikipedia.comwww.wikipedia.com