Rock Layers Rock Layers

Observing and Investigating that Observing and Investigating that Rocks are Found in LayersRocks are Found in Layers

By: Carly Gallo, Lauren Carney, and By: Carly Gallo, Lauren Carney, and Katherine LocastoKatherine Locasto

3 Types of Rocks 3 Types of Rocks

• Igneous – A rock formed by the crystallization of magma

or lava • Metamorphic

– Formed when the composition or texture of a rock changes because of changing temperature, pressure and/or reactions

• Sedimentary– form as layers known as strata

Igneous Rocks

Metamorphic Rock Sedimentary Rock

Rock Layers Rock Layers

• Rock layers, also known as strata, are found throughout the Earth. The oldest layers of rock can be found on the bottom, while the youngest layers of rock are found on top.

How Do You Know Which Layers How Do You Know Which Layers Are Which?Are Which?

• Rock layers can be identified by color, thickness and resistance to erosion.

• These are all properties that are linked to the composition and origin of the rocks.

Nicholas Steno Nicholas Steno

• He developed the Principle of Original Horizontality, which states that sedimentary rocks are originally formed in horizontal layers, but sometimes they undergo change and cause them to be tilted.

Activity: Layers of Rock Activity: Layers of Rock

• Paleozoic Era – 543 Million Years Ago – Represented by green cubes

• Mesozoic Era – 245 Years Ago – Represented by pink cubes

• Cenozoic Era – 65 Million Years Ago – Represented by orange cubes

What To Do What To Do

• Build cubes according to the order in which the layers formed.

• After you have formed the layers, create a sketch on your blank piece of paper of your rock layers.