1. Warm-up 10/27
What is the half-life of Carbon?
2. The element chaparralium has a half-life of 24,000 years. If a fossil contains 25% of the original amount of chaparralium, how old is this fossil? Show your work!

2. Warm-up 10/28-29
1. Which layer of the Earth do you think is most important and why? 2. If a fossil has .195% of the original amount of an element, how many half lives have passed? 3. Which type of dating would you use to find the age of an ancient basket made of natural fibers? Why?
End

3. Continental Drift
Identify and label the different continents on your map.
North America
South America
Africa
Europe
Asia/India
Australia
Antarctica

4. End Continental Drift Take 2 minutes to observe the world map.
Make 2 observations about the continents’ coast lines.
Make 1 inference based on your observation
End

5. Continental Drift
Take 3 minutes and work with your partner to try and fit the continent puzzle pieces together.
End

6. End Continental Drift Do they fit together perfectly?
What may have caused the coastlines to change over time?
Come up with 2 possible reasons (2 minutes)
End

7. Continental Drift
Look at the small pictures on your puzzle pieces.
Those are fossils found in those areas of each continent.
Take 2 minutes to observe the fossil placement.
Make 2 observations
Make 1 inference
End

8. Continental Drift
Rearrange your puzzle so that all of the fossil segments line up. (2 minutes)
End

9. End End Continental Drift
Take 3 minutes to draw in dots along the plate boundaries to show recent earthquakes. (large dots = more activity, small dots = less activity)
End
End

10. Continental Drift
Take 2 minutes to draw in triangles to show volcanic activity.
End

11. Continental Drift
Take 2 minutes to observe the marks you just made on your map.
Make 2 observations
Make 1 inference
End

12. Concept with no mechanism
Continental Drift
Alfred Wegner
Concept with no mechanism

13. Wegener’s evidence of drift
The continents fit together.
Fossils of the same organisms are found along the coasts of different continents.

14. Pangaea
Supercontinent
300 million years ago
Cycle

15. Plate Tectonics Scientific theory (concept + mechanism)
Lithosphere is broken up into “tectonic plates”
Moved by convection of asthenosphere
Past plates and current plates
How do we know?
How many?
Farallon Plate
Farallon Plate video in picture

16. More Evidence for Plate tectonics
Seismic, volcanic, and geothermal activity along plate boundaries.

17. How would you explain this evidence?

18. Evidence for Plate tectonics
4. Sea Floor Spreading
Mid-ocean ridges
Tectonic plates moving separating
New magma rises
Form new oceanic crust
Older crust pushed away

19. More Evidence for Plate tectonics
5. Magnetic Reversals
Molten rock
Magnetic minerals
Align with magnetic field
Magnetic field reverses
177 times in 85 million years
Last 600,000 years ago
Recorded in rock
Similar pattern to age of rocks
Reverses every 500,000 years or so (exact division is 480,225.98)

20. Causes for Plate Tectonics
Convection
Cools
Asthenosphere
More dense
Heated rock
Expands and rises

21. 2 main types of movement 1. Spreading 2. Subduction
New material pushed up at ridges
Pushes older material away
2. Subduction
Denser plate sinks
Pulls rest of plate
Picture has hyperlink to
National Geographic – Colliding Continents

22. Warm-up 11/3 & 7
Which piece of evidence for continental drift do you think is most compelling and why?
Compelling: strong and forceful, having influence