If Rocks Could Only Talk, What Would They Tell Us?

How Old is the Earth? 1 million years old? 1 million years old? 1 billion years old? 1 billion years old? No! No! 4.6 billion years ago the earth had a violent beginning 4.6 billion years ago the earth had a violent beginning Sit back as the story unfolds. Sit back as the story unfolds. Once Upon a Time… Time

PRECAMBRIAN ERA

PALEOZOIC ERA

MESOZOIC ERA ALSO KNOWN AS AGE OF THE REPTILES

CENOZOIC ERA ALSO KNOWN AS AGE OF THE MAMMALS

How do we Know all This?

What is Igneous Rock? Formed from cooling Lava (outside volcano) or Magma (inside volcano) Formed from cooling Lava (outside volcano) or Magma (inside volcano) Extrusive: cools outside the Earths Crust Extrusive: cools outside the Earths Crust Intrusive: Cools inside the Earth Intrusive: Cools inside the Earth Extrusive: Obsidian Intrusive: Granite

What is Sedimentary Rock? Formed from Weathering and Erosion Formed from Weathering and Erosion Types: Types: –Clastic: pieces compacted and cemented together –Chemical: formed by evaporation and precicpitation –Organic: coming from living organism

What is Metamorphic Rock? Formed by heat and pressure Formed by heat and pressure Foliated: Has bands Foliated: Has bands Nonfoliated: Has no bands Nonfoliated: Has no bands

How Can We Date Rocks?

Half-life: The time it takes for half the element to decay