Historical Figures Late 1500s  Abraham Ortelius was the first one to imagine the continents were joined together before drifting to their present positions. 1620s  Sir Francis Bacon noticed that the coastlines of South America and Africa were similar. Late 1800s  Eduard Suess, an Austrian Geologist, was the first to realize that South America, Africa, India, Australia, and Antarctica were connected at one point.  He named the large landmass Gondwanaland which contained all the southern continents.

Alfred Wegener Born 1880 died 1930 German Meteorologist First to come up with the idea of continental drift because the Earth fit together like a jigsaw puzzle. Most notable for his theory of continental drift proposed in This theory said that the continents were slowly drifting around the earth but he could not demonstrate his theory. Credited with the Theory of Continental Drift because he provided EVIDENCE!! Theory of Continental Drift: S tates that all the continents were once together and have since moved apart.

Modeling Continental Drift Part One  UNLINED PAPER Tear a sheet of unlined paper into seven jagged, unequal pieces. Make sure to shuffle the pieces once you have all seven and put them in a pile. Next, trade your pile of paper with a partner. Now, with a new pile of paper, try to fit the seven pieces of unlined paper back together so that they look like the original sheet of paper.

Part Two  NEWSPAPER Same procedure as the unlined paper Tear the newspaper into seven jagged, unequal pieces. Shuffle the pieces up and put them into a pile. Trade your pile with a partner. With your new pile of ripped newspaper, try to put the pieces back together like the original sheet.

Pangaea  250 million years ago, all Earth; refers to one supercontinent that contained all the continents we have today.

Laurasia  large landmass that contained the northern continents. Gondwanaland  large landmass that contained the southern continents.

The continents didn’t necessarily “fit” together at their ever changing shoreline but rather at the continental shelf. Shorelines are eroded much too dramatically to be clear evidence of a perfect match

Fossil Safari Imagine that you are going on a world-wide expedition to find fossils of extinct organisms. From the evidence you find, you hope to obtain a picture of what life on Earth was like about 250 million years ago.

North America South America Africa Europe Asia Australia Antarctica

A (Yellow) Glossopteris

B (Orange) Kannemeyeria

C (Blue) Labyrinthodont

D (Purple) Lystrosaurus

E (Red) Thecodont

F (Green) Cynognathus

G (Pink) Mesosaurus

North America South America Africa Europe Asia Australia Antarctica A A A A A A B B B B B C C C C D D D E E F F G G

Fossil Evidence Fossils of various extinct species were found in very unusual modern day places. Physically, many of the prehistoric animals simply could not have traveled the far distances. Glossopteris, an extinct plant, was found in many unusual modern day climates. The same type of plant cannot exist in such extreme climate variations, supporting continental drift

Rock Sequences Many continents in the southern hemisphere exhibited very similar rock and fossil sequences. Some similar rock sequences can be found in India, South Africa, South America, Australia, Antarctica, Madagascar, and Falkland Islands He named this the “Gondwana Sequence”

Rock Sequences

Similar Geologic Structures Geologic structures found in Newfoundland matched up with structures in Ireland, Scotland, and parts of Scandinavia. Rock structures in the Appalachian Mountains also matched up with structures in Morocco and Algeria in Africa.

To the left is a bird’s eye view of the Appalachian Mountain range next to the Atlas Mountains in Morocco. Notice anything interesting? These two mountain chains were formed by the same chain when they were connected.

Glacial Evidence Glaciers are large bodies of ice that form over land. Polar Ice Caps are examples from today Move very slowly over land when they become heavy enough As they move, they deposit rocks and other debris called glacial till deposits These rocks and debris can leave behind “scratches” called striations.

Glacial Striations (scratches) were found to match up across the oceans, which strongly suggested the continents were once attached

Glacial Till Deposits Glacial Till Deposits  Random sediment deposited by glaciers as they move over landscapes Wegener studied glacial till deposits in the southern hemisphere and noticed that they did not match up with the positions of the continents today. If they were deposited on today’s map, glacial movement would be incredibly erratic and improbable. The only explanation is a once super continent where the glacial deposits would indicate a much smoother movement.

This wouldn’t make any sense… So how could this be so?

…if you push the continents back together, here is what you get…

Paleo-climate Data Wegener decided to take his research a step further and examined ancient climate data. Particular deposits would designate a particular climate zone: EVAPORITES  Imply hot, arid climate. Today, these are 30° north or south of equator COAL AND CORAL  Warm, tropical water. Locate ancient equator GLACIAL DEPOSITS  Locate poles Explanation? Either a movement of the plates or a movement of the poles

So Let’s Recap Wegener’s Evidence… 1. FIT  He observed that the continental shelves look like they fit together at one point in history. 2. FOSSILS  Found fossil remains in very different modern day climates which could only be explained by continental drift. Also, the locations of certain fossils suggested that the continents must have been joined together at one point in history. 4. GLACIERS  250 m.y.a., huge glaciers moved along the continents and left behind scratch marks. When these striations were matched up, they showed that the continents must have been once together. 3. ROCK SEQUENCES/STRUCTURES  He found that not only were there similar rock sequences across oceans, but very similar mountain chains and other rock structures. 5/6. GLACIAL & OTHER DEPOSITS/PALEOCLIMATE  Glacial deposits, along with other deposits, indicated that the only explanation for the glacial movement was continental drift. Also, other deposits indicated a very different story of what the climate was like in the past.