Fascinating Fossils

A Unison Reading by

Alfredo, Luis, Jesus, Gian, and Marcos

[The group stops at the end of the first paragraph]Alfredo: Everyone understand this paragraph?Jesus: Yes, you?Alfredo: The dinosaur dies and is in the rock. Then the

people find the rock.Luis: Miss, he said it all!Jesus: The fossil people can know how the life changed.Luis: I understand that the dinosaurs died million years

ago and we can find them all over the world.Jesus: The bones.Gian: The animals, plants die, the life on Earth changed

through time.Alfredo: And at the museum we can see the fossils.

Relative Dating

There are rules to relative dating. Here are the ones you need to know:

1) Law of Original Horizontality2) Law of Superposition3) Law of Cross-cutting Relationship4) Law of Included Fragments5) Unconformities

Laws of Original Horizontality and Superposition

1) Layers are deposited horizontally

2) The oldest layer is on the bottom, the youngest layer is on the top

Law of Superposition: The Pizza Rule

Law of Superposition

Law of Cross-Cutting Relationships

A fault or intrusion that goes through a rock layer is younger than that rock layer

Law of Cross-Cutting Relationships: The Twinkie Rule

Law of Cross-Cutting Relationships

Law of Included Fragments

• A rock layer with pieces of another rock layer inside it is younger than the pieces

• Pieces of a rock layer inside another rock layer are older than the rock layer they are inside

Law of Included Fragments: The Chocolate Chip Cookie Rule

Unconformities

An unconformity can represent:– lost time–A tilting or

folding event