SCIENCE LESSON 2

Is a chronological system that divides Earth's history into different time interval based on major geological events, climate changes, and the appearance of extinction of an organisms

Geologic Time Scale (GTS)

Scientist develop the Geologic Time Scale using evidence from

-Rocks

-Fossils

-Rock layers (strata)

Geologic Time Scale develop using the evidence from

1. Rocks

2. Fossils

3. Rock layers (strata)

Serves as as the standard timeline used by geologist and paleontologist

Geologic Time Scale (GTS)

Scientist created the geologic time scale to

1. Organize Earth's long history

2. Compare rock layers

3. Study fossils

4. Record changes in life through time

5. Understand environmental changes

6. Explain important geological events

Major Divisions of the Geologic Time Scale

1. Eon

2. Era

3. Period

4. Epoch

Largest divisions of geologic time

Eon

A subdivision of an eon

Era

A subdivision of an era

Period

A subdivision of a period

Epoch

Four Eons

1. Hadean Eon (4.6 - 4.0 BILLION YEARS AGO)

2. Archaean Eon (4.0 - 2.5 BILLION YEARS AGO)

3. Proterozoic Eon (2.5 BILLION - 541 MILLION YEARS AGO)

4. Phanerozoic Eon (541 MILLION YEARS AGO - PRESENT)

Marks the beginning of earth

Hadeon Eon (4.6 - 4.0 BILLION YEARS AGO)

Marks the beginning of earth

Characteristics:

• Earth formed

• Surface was extremely hot

• Frequent eruption occurred

• Ocean had not yet fully formed

• No life existed

Hadeon Eon (4.6 - 4.0 BILLION YEARS AGO)

Characteristics:

• Earth form

• Surface was extremely hot

• Frequent eruption occurred

• Ocean had not yet fully formed

• No life existed

Hadeon Eon (4.6 - 4.0 BILLION YEARS AGO)

Life first appear during this Eon

Archaean Eon (4.0 - 2.5 BILLION YEARS AGO)

Characteristics

• Earth cold

• Oceans form

• The first simple life forms evolved

• First continents appeared

Life first appear during this Eon

Archaean Eon (4.0 - 2.5 BILLION YEARS AGO)

• Earth cool

• Oceans form

• The first simple life forms evolve

• First continents appeared

Life first appear during this Eon

Archaean Eon (4.0 - 2.5 BILLION YEARS AGO)

• Earth cold

• Oceans form

• The first simple life forms evolve

• First continents appeared

Archaean Eon (4.0 - 2.5 BILLION YEARS AGO)

• Earth form

• Surface was extremely hot

• ocean had not yet fully formed

• no life existed

Hadeon Eon (4.6 - 4.0 BILLION YEARS AGO)

Important Events

• Oxygen increased in the atmosphere

• Larger and more complex organisms evolved

• Continents continue to grow

• Earth became more suitable for complex life

Proterozoic Eon (2.5 BILLION - 541 MILLION YEARS AGO)

Characteristics

• Oxygen increased in the atmosphere

• Larger and more complex organisms evolved

• Continents continue to grow

• Earth became more suitable for complex life

Proterozoic Eon (2.5 BILLION - 541 MILLION YEARS AGO)

• Oxygen increase in the atmosphere

• Larger and more complex organisms evolve

• Continents continue to grow

• Earth became more suitable for complex life

Proterozoic Eon (2.5 BILLION - 541 MILLION YEARS AGO)

Characteristics

• Most plants and animal appeared

• Fossils became abundant

• Dinosaurs live during this Eon

• Humans are eventually appeared

Phanerozoic Eon (541 MILLION YEARS AGO - PRESENT)

• Most plants and animals appeared

• Fossils became abundant

• Dinosaurs live during this Eon

• Humans are eventually appeared

Phanerozoic Eon (541 MILLION YEARS AGO - PRESENT)

We are living currently in the

Phanerozoic Eon

Three Eras of the Phanerozoic Eon

1. Paleozoic Era

2. Mesozoic Era

3. Cenozoic Era

Age of Ancient Life

Important events:

• Cambrian explosion occurred

• Marine life flourished

• First fish appeared

• First amphibians evolved

• First reptiles appeared

• Forest develop on land

Palezoic Era (541 - 252 MILLION YEARS AGO)

Age of Ancient Life

Palezoic Era (541 - 252 MILLION YEARS AGO)

Important Events:

• Cambrian explosion occurred

• Marine life flourished

• First fish appeared

• First amphibians evolved

• First reptiles appeared

• Forest develop on land

Palezoic Era (541 - 252 MILLION YEARS AGO)

Periods

• Cambrian

• Ordovician

• Silurian

• Devonian

• Carbonferous

• Permian

Palezoic Era (541 - 252 MILLION YEARS AGO)

Periods of Paleozoic Era 541 - (252 MILLION YEARS AGO)

1. Cambrian

2. Ordovician

3. SiIurian

4. Devonian

5. Carboniferous

6. Permian

Age of dinosaurs

Important events:

• Dinosaurs dominated earth

• First birds evolved

• First mammals appeared

• Flowering plants develop

• Ended with a mass extinction

Mesozoic Era (252 - 66 MILLION YEARS AGO)

Age of dinosaurs

Mesozoic Era (252 - 66 MILLION YEARS AGO)

Important Events

• Dinosaurs dominated eart

• First birds evolve

• First mammals appeared

• Flowering plants develop

• Ended with a mass extinction

Mesozoic Era (252 - 66 MILLION YEARS AGO)

Periods of Mesozoic Era (252 - 66 MILLION YEARS AGO)

• Triassic

• Jurassic

• Cretaceous

Periods

• Triassic

• Jurassic

• Cretaceous

Mesozoic Era (252 - 66 MILLION YEARS AGO)

Years of Hadeon Eon

4.6 - 4.0 billion years ago

Years of Archaean Eon

4.0 - 2.5 billion years ago

Years of Proterozoic Eon

2.5 BILLION - 541 MILLION YEARS AGO

Years of Phanerozoic Eon

541 MILLION YEARS AGO PRESENT

Years of Paleozoic Era

541 - 252 MILLION YEARS AGO

Years of Mesozoic Era

252 - 66 MILLION YEARS AGO

Years of Cenozoic Era

66 MILLION YEARS AGO PRESENT

How old is the Earth

4.6 BILLION YEARS OLD

Age of Earth

4.6 BILLION YEARS OLD

Why Do We Study Earth's History?

By studying Earth's history scientist can better understand :

• Climate change through time

• The evolution of living organisms

• Mass extinctions

• Continental movement

• The formation of natural resources such as coal oil and minerals. Understanding Earth's past help scientists explain present-day geological processes and prepare for the future