1. Rock Layers Absolute Age Relative Age Law of Superposition Fault

2. Who Dunit?
Someone took the last cookie in the cookie jar last night. The last person to leave the scene is the culprit. Who was it?
Clues
The butler walks to work
The handyman rides a bike
The cook rides a motorcycle
The maid drives a car
The nephew has a seeing-eye dog

3. Who Dunit?

4. Objectives
8.E.2 - Understand the history of Earth and its life forms based on evidence of change recorded in fossil records and landforms.
What to expect this unit??
2 quizzes – 3/11 & 3/18
1 test – 3/22
Project

5. Types of Rocks (review)
Igneous Rock (formed when magma cools)
Metamorphic Rock (other rock types transformed by heat and pressure)
Sedimentary Rock (rock formed from minerals deposited near bodies of water; forms rock layers)

6. Relative Age vs. Absolute Age
The age based on compared position relative to other rocks – applies to both sedimentary and igneous rocks
Absolute Age
The number of years since the rock has formed based on radioactive decay of atoms in minerals in Igneous rock and some metamorphic rock

7. Half-Life
the time taken for the radioactivity of a specified isotope to fall to half its original value.

8. Law of Superposition
In horizontal layers of sedimentary rocks, the oldest layer is at the bottom.
Each layer above
is younger than
the layers below it.

9. Law of Superposition Which layer is the oldest?
Which layer is the youngest?

10. Faults a break or crack along which rocks move.
Sometimes an igneous intrusion or fault will cut across or into the rock layers.
The intrusion or fault will always be younger than the rocks being intruded or displaced.

11. Principle of Cross-cutting
Intrusion: is any formation of intrusive igneous rock; rock formed from magma that cools and solidifies within the crust of the planet.
During some plate movement, igneous rock forms in the process.

12. Unconformity
Erosion causes new rock layers to meet older rock layers. This leads to a “gap in the geologic record” (missing rocks layers and fossils).

13. Principle of Superposition

14. Principle of Superposition
Number the events below in the order they occurred in time, 1-9
__ earthquake
__ deposit D
__ deposit B
__ deposit G
__ intrusive lava
__ rocky deposit R
__ river cuts through
__ deposit E
__ deposit A

15. Video While watching the video answer –
How does the Grand Canyon form and what is the evidence to support this?