Continental drift theory and supporting evidence by Liam H

The theory of continental drift was the idea that all seven continents that we know of today, where all connected as one giant continent known as Pangea.  Over the coarse of millions of years, this giant continent broke up and drifted apart into 7 smaller continents. Even today, the continents continue to drift away from eachother, and scientists claim that in the future, they will all collide and create another Pangea. Millions of years ago, all land on earth was catagorized into two titles. First Gondwanaland, in the southern hemisphere which consisted Africa, South America, India, Australia, and Antarctica. Second Laurasia, in the nourthern hemisphere which consisted of North America, Asia, and Europe. All of this information and knowlage came from one very smart scientest named Alfred Wegener. He studied his theory and evidence for years before he came out and told everyone his ideas. At first, this theory was thought to have been baloney, and the scientests thought Alfred Wegener was crazy. He had this whole idea on what happened, but he was unable to explain why all the continents had moved to were they are today. He didnt know of the tactonic plates and the mid-ocean ridge that scientests had discovered years later.
 



Fossils are some of the best evidence for the continental drift. For example, fossils from an ancient reptile Cynognathus, was found in both South America and Africa. As we all know today, these two continents are thousands of miles apart, and a reptile cannot swim 2000 miles. The only reasonable explanation for this, is that these two continents were once connected as one, and the Cynognathus died there, fossilizing; and then the continent split. Another define example is the plant glossopteris that was found all over the world. The amazing thing is that this plant requires tropical conditions to grow, and it was found in parts of Antarctica. We know this continent today as a giant heap of ice, but millions of years ago, it was much closer to the equator and was suitible for life. This plant is pure evidence of  Alfred Wegeners theory.

 

Glacier deposits have been found in areas today that are tropical and hot, that dont and cant support glaciers. For example, Glacial deposits have been found in Africa, and South America, which are two of the most tropical and hot places on Earth. 220 million years ago, these two continents where much farther from the equator and much closer to the south pole. In the time they where there, glaciers and ice filled the land. Once the continents moved north to were they are today, the glaciers thawed, but the evidence remained.



     
Mountain ranges are also great evidence for Pangea. As we have all learned in class, when land collides, it folds over and builds up creating mountains. The eastern coastline of South America and the western coastline of Africa, are proof further supporting Pangea. On both coastlines there are imense mountain ranges, and these two continents seem to fit into eachother; meaning that these two continents once collided creating great mountain ranges, that then broke apart over the course of millions of years. Werever we see mountain ranges, we know there has been a collision of land. Another example is the Himalayas. Millions of years ago, India collided with Eurasia, and created the biggest mountains we know of today.





Coal beds contain some of the greatest evidence for the continental drift. Coal is the remains of vegetation that has been heated and pressurized over the course of millions of years. In order for plants to grow and eventually create coal, they need to be in a tropical and hot enviroment. Coal cannot be formed in present day Antarctica because it is just too cold there and it cant support any vegetation. Scientest have found coal smack in the middle of Antartica. Which could only suggest, that Antarctica used to be a lot warmer than it is now. In order for it to be warmer, it needed to be closer to the equator, so scientests presume that Antartica used to be much farther north than it is today.

Have you ever noticed how all seven continents kind of look like puzzle pieces that fit in to eachother? Well so have scientests. South America seems to fit perfectly into Africa. And Madagascar seems to fit perfectly into Africa as well. This is all evidence that scientests have used to proove contiental drift. In the days of Pangea, South America and Africa where connected as one, with all the other continents. As the tectonic plates shifted, the land mass broke apart into two chunks that look as if they could fit back together.