Warm-Up What are the 4 pieces of evidence that support the theory of Continental Drift? Time’s Up!

Plate Tectonics

Plates ◦ Divisions of lithosphere ◦ Moving on asthenosphere

Wegener – Continental Drift Theory Early 1900s Once single landmass - Pangaea Broke up – Laurasia, Gondwana Drifted to present location

Over the past 300 million years the continents have spread apart from each other.

Continental Drift Evidence For Wegener ◦ Fitting together of continents ◦ Similar things on distant continents  Fossils  R ocks

Sea-Floor Spreading Evidence for continental drift Mid-ocean ridges ◦ Tectonic plates moving separating ◦ New magma rises ◦ Form new oceanic crust ◦ Older crust pushed away

Magnetic Reversals Evidence for continental drift 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

Causes for Plate Tectonics Convection ◦ Asthenosphere ◦ Heated rock  Expands and rises ◦ Cools  More dense

Inquiry Activity Follow the directions on the worksheet to complete the activity. When you are ready for shaving cream raise your hand and I will get you some.

Tf0

Plate Tectonics Movement ◦ cm/yr ◦ Measured by GPS Interact at boundaries – 3 types ◦ Collide ◦ Separate ◦ Slide past Earthquakes can occur at all

What will Denver be like? Earth’s History to 100 million years from now now Notice what Colorado/North America look like at the end of that video…

Short Constructed Response Using the information you have learned about continental drift, make a prediction about what Earth’s continents will look like in 100 million years. Make sure to support your claim with at least three pieces of evidence and provide commentary for each.