Topic: Discovering Plate

Tectonics

Started with Alfred Wegener In the 1910s he

developed the first theory behind plate

tectonic called “Continental Drift”

Why would Wegener think the Continents Drifted?

1) Continents appear to “fit” together

Continental Drift Theory

2) Similar minerals, fossils, & rocks found on continents oceans apart

3) Glacial evidence on equator

4) Matching mountain chains in US & Europe

5) Rocks on the Earth’s surface are deformed (folded, faulted, tilted)

Sedimentary and/or Igneous rock are deposited horizontally (strata)

Tilted Strata (Layers)

Folded Strata

Mts. formed from Folding

Faulting

Ce fossile d'ammonite de deux mètres de diamètre est visible au Musée de Paléontologie de Münster (Allemagne)

This ammonite fossil is 2 meters in diameter and is on

display at the Munster Muesum of Paleontology

Mount Everest home.netcom.com/~debissy/

“The presence of limestone and ocean marine fossils at the top of these mountains is one of the key pieces of evidence cited that advanced the idea of plate tectonics (large chunks of the Earth’s surface moving over molten rock in the Earth’s core) when it was first proposed as a theory in 1915.”

http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=15300

• Marine limestone is found near the top of Mt. Everest (world’s tallest mountain)

6) Displaced fossils -caused by uplift (forming mountains) & subsidence (sinking of the surface).

• Wegener died in the early 1930’s and his work was forgotten until World War II

• Harry Hess, a geologist and seaboat captain, made a discovery under the Atlantic Ocean

What is under the Atlantic Ocean? Mid-Atlantic Ridge

7) Rocks on opposite sides of ocean ridges

match in type, age & magnetic polarity.

Magnetic Field Reversal

The location of Earthquakes

8) Earthquake and volcano patterns follow plate boundaries.

FQ: List the locations from youngest to oldest.

A B C

Lab #18 Plate Tectonic Flip Book