What are the clues that serve as evidence for continental drift? Do Now: Take out homework What are the clues that serve as evidence for continental drift?

Module F: Chapter 4 Plate Tectonics

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Module F: 4.1 Continental Drift Objectives: Describe the hypothesis of continental drift. Identify evidence supporting the theory of continental drift.

Evidence for Continental Drift 1. Pangaea ____________________ 2. Fossil Clues 3. Climate Clues 4. Rock Clues

1. Pangaea - ______________ thought that all the __________ were joined together at some time in the past - 1912: Wegener proposed the hypothesis of _______________ Alfred Wegener continents continental drift

continental drift horizontally Wegener continents Pangaea 200 million - The theory of ________________ states that continents moved ___________ to current locations - ________ believed all __________ were once connected as one large landmass (________) that broke apart about ___________ years ago continental drift horizontally Wegener continents Pangaea 200 million

2. Fossil Clues Mesosaurus Glossopteris __________ - reptile found in South America and Africa ____________ – fern found in Africa, Australia, India, South America and Antarctica Glossopteris THINK!!! What is significant about where the fossils are found? Are the continents, they are found on, near one another at all?

Mesosaurus Findings!!!

Mesosaurus

MESOSAURUS Mesosaurus ("middle lizard") was an odd, fresh-water dwelling reptile (not a dinosaur) that lived from the late Carboniferous. It was a lightly-built, four-legged animal with an elongated head and snout with nostrils near its eyes. It had a flattened tail that was probably used for swimming. It was about 1.5 feet long. This carnivore probably ate fish and shrimp, catching them with its mouth. It was a primitive reptile that returned to the water about 300 million years ago after having adapted to the land; one of the first aquatic reptiles.

Glossopteris

Glossopteris Findings!!!

3. Climate Clues fossils Arctic Ocean South Australia South - _______ of warm-weathered plants were found on the island of Spitzbergen in the _______________ - glacial deposits and grooves found in _______ America, Africa, India, and ___________ Arctic Ocean South Australia How could you explain why glacial deposits are found in areas where no glaciers exist today? - Wegener believed that South America, Africa, India and Australia were near the _______ Pole at one time; the theory of ___________________ split them up South continental drift

Glacial Findings!!!

4. Rock Clues Appalachian Europe similar rock structures found on different continents (example: parts of the ____________ Mountains of the eastern United States are similar to those found in Greenland and western _________) Appalachian Europe

Appalachian Mountains

Similar Rock Findings!!!

How could continents drift? - Wegener died before he could provide evidence - Rock, fossil, climate and new clues such as _________________ (learned about in 4.2) help provide a more precise explanation seafloor spreading

Let's Review!!! State one reason why Wegener’s ideas about continental drift were not accepted. 2. How did Wegener use climate clues to support his hypothesis about continental drift?