From Biologic to Geologic Evolution

Lets look at the Earth!

With Your Group:

How does our new knowledge of refraction through different densities give us information about the earth?

Evidence From Earthquakes: P&S waves

P (primary) waves= Compression (push/pull waves)

S (secondary) waves= Transverse (up/down waves)

Mohorovicic (Moho) Discontinuity

Plate TectonicsPlate Boundaries and Interactions

The Theory of Plate Tectonics The Earth’s surface is divided into plates that move and

interact with one another.

Overview of Plate Boundary Interactions

Divergent Plate Boundaries

• Plates are moving apart. New crust and lithosphere is “created”

• Associated with ocean ridges, rift valleys, volcanism, earthquakes and high heat flow.

Examples found on Earth: Mid-Atlantic Ridge, African Rift Valley, Iceland

• Plates are moving towards each other. Old crust and lithosphere is “recycled”.

• Associated with ocean trenches, island arcs and mountain ranges.

• Earthquakes and volcanism are common.

Convergent Plate Boundaries

Examples found on Earth: Himalayas, Pacific Ring of Fire, Andes Mountains, Marianas Trench

• Plates slide past each other, oftentimes connecting two ridges or trenches.

• Crust is deformed or fractured; Lithosphere is neither created nor recycled.

• Long faults and earthquakes common.

Examples found on Earth: San Andreas Fault

Transform Plate Boundaries

Plate Boundaries, Earthquakes and Volcanic Activity

Continental Drift: Pangea

Matching Fossils

Matching Mountain Ranges

Glacial Evidence

Magnetism

Earthquake Patterns

Age of Rock

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