9.1.2 Archean Eon

Archean Eon

It is the second eon in Earth’s geologic history

3.85 to 2.5 Ga

When did the Archean Eon occur

45.6% of the day

If you compress the GTS in 1 day, how long is the Archean Eon

Continents

What formed during the Archean

Archean

When did the Earth’s earliest organisms lived

0.8 km asl

What was the average elevation on Earth above sea level

3.8 km bsl

What was the average depth on Earth below sea level

On continents

Where do the 95% of people on Earth live

On volcanic islands

Where do the 5% of people on Earth live

Granite-Gneiss Complexes, and Greenstone Belts

What are the rocks of the Archean Eon

1600 degrees Celsius

Surface temp of Komatiite then

1350 degrees Celsius

Surface temp of Komatiite now

Eoarchean; Paleoarchean; Mesoarchean; Neoarchean

The 4 eras under the Archean eon

3.85Ga to 3.6 Ga

When did the Eoarchean era occur

3.6Ga to 3.2Ga

When did the Paleoarchean era occur

3.2Ga to 2.8Ga

When did the Mesoarchean era occur

2.8Ga to 2.5Ga

When did the Neoarchean occur

Formation of Algoma-type BIF deposit; Formation of first theorized supercontinent

What are the significant geologic events that happened during the Eoarchean era

Formation of Algoma type BIF

What happened during 3.8 Ga to 3.1 Ga

3.8 Ga to 3.7 Ga

How old is the Greenland stromatolite in Isua Supracrustal Belt

Greenland Stromatolite

It is the first chemical evidence of life in Greenland

Formation of first theorized supercontinent

What happened during 3.6 Ga

Vaalbara

What is the first theorized supercontinent

3.1 Ga

When did Vaalbara completed its formation

Kaapvaal Craton South Africa; Pilbara Craton Western Australia

The two continental crust that were once part of the Vaalbara supercontinent

Formation of Archean Stromatolites in Hamelin Pool, Shark’s bay, Western Australia; Appearance of bacteria

What are the significant events that happened during the Paleoarchean era

3.5 to 3.3 Ga

How old are the Stromatolites in Western Australia

3.5 Ga

How old are the first bacteria

Cyanobacteria

What are the first bacteria

Hydrogen Sulfide

The source of Hydrogen

Formation of the 2nd supercontinent; and Appearance of Acritarchs

What are the significant events that happened during the Mesoarchean era

Ur

What is the 2nd supercontinent

Appearance of Acritarchs

What happened during 3.2 Ga to 1.4 Ga

Formation of Ur

What happened during 3.1 Ga

3.0 Ga

How old is the oldest known undisputed Stromatolite in Barberton Greenstone Belt South Africa

Australia, Madagascar, India

They are the present-day Ur

Half a billion years younger

How young is Ur relative to Vaalbara

Formation of Kenorland; Formation of Superior Type BIF; Break-up of Vaalbara

What are the significant geologic events that happened during the Neoarchean era

Formation of Kenorland

What happened during 2.7 Ga

Kenorland

It is the widely accepted supercontinent

Kenoran-Algoman Orogeny

The mountain-building event that supported the formation of Kenorland

Laurentia; Baltica; Western Australia; Kalahari

It comprises Kenorland

2.6 Ga to 1.8 Ga

When did the first Superior type BIF were formed

2.5 Ga

When did the Vaalbara break-up

Formation of the first Superior Type BIF

What happened during 2.6 to 1.8 Ga

Break-up of Vaalbara

What happened during 2.5 Ga