Earth’s Dynamic Crust. Aim: What is meant by “Dynamic Crust” and what evidence can we observe to support it? Do Now Open your review books to p. 245 In Figure 12-1 Diagram D label layers 2,3,4, and 5 using your scheme for sedimentary rock identification (ESRT)
HW: R+H 244-245, A+E 1-8
Uniformitarianism – The same processes that shaped the earth in the past are the same processes shaping the earth today.
Convection currents in the mantle put stress on the crust causing it to move and crack.
Cracks join up to create crustal plates.
Occurs Because Rock Types Are Ductile – Bend Easily and are being compressed.
Foot wall is underneath the fault.
Hanging wall rests on the fault.
This occurs because the rocks are brittle or easily broken. This is tension (although could also compress reversing the fault.
Caused by compression.
Surface Waves or L-waves
b. How long did it take the P wave to get there?
c. If the P wave arrived at 2: 45 pm when did the earthquake occur
HW: R&H 255-258 A&E 29-41
The Moho is a boundry between the crust and the mantle at which waves refract.
1. Using the diagram below please label the following; disturbed or undisturbed, oldest rock layer, foot wall, hanging wall, the stress (tension, compression, or shearing), type of fault, property of the rocks (brittle or ductile)
Island Arcs, mountain ranges and ocean trenches can be formed.
Continental crust which is always thicker and less dense will uplift and thinner, denser oceanic crust will always subside (go down) or subduct (slide beneath another plate)
HW:R&H pp.259-267, A&E #42-68.
1. Puzzle Like Fit of the Continents
2. Matching Fossils on Different Continents
4. Glacial Deposits
3. Matching Rock Formations