Plate tectonics is the theory that the outer layer of the Earth is divided into several plates that slide over the mantle, the rock layer on the inner core. The plates act as a hard, rigid shell compared to the Earth's mantle. The German astronomer and meteorologist Alfred Wegener (1880-1930) who proposed that the continents in the geological past were united in a supercontinent named Pangea.
Earth, 225 million years ago, was formed on the surface by a single structure called "Pangea" (all continents together), which was fragmented to form the continents as we know them today. Now the planet's surface is covered by plates in relative motion between them.
 |
| Alfred Wegener |
Earth, 225 million years ago, was formed on the surface by a single structure called "Pangea" (all continents together), which was fragmented to form the continents as we know them today. Now the planet's surface is covered by plates in relative motion between them.
It also explains the formation of mountain ranges. It also gives a satisfactory explanation of why earthquakes and volcanoes are concentrated in specific regions of the world (as the Pacific Ring of Fire) or why large trenches are along islands and continents and not in the center ocean.
Plants and animals fossils also suggest the existence of Pangea. Impressions of leaves of a fern, Glossopteris are widely distributed in rocks of Africa, South America, India and Australia. Reconstruction of Gondwana restricts the area of influence of Glossopteris to a contiguous region of the supercontinent. The distribution of terrestrial vertebrate fossils also supports this interpretation. The existence of tetrapods on all continents during the Triassic is an indication that there were connections between the continental land masses. In particular the distribution of the fossil reptile Mesosaurus in Africa and South America, the absence of similar species in other regions is a strong indication of continuity between these continents during the Permian.
Well my opinion on this theory is that everything they say is right because they have evidence of how the tectonic plates are and the things that happened before we existed are true. I agree with this theory.
Reflection
The thing that I enjoy on this project is that I can work any time in my work in any activity Ms.Kara give to us lot of chooses to do this project, and we can work by my own or with a partner.
Well the most challenging during this project was that some times I don't had any idea to make my model.
The new things that I learn with the project was that I learn more about all the topic not only just one part.
I can improve in how to explain my work more and work more hard.
Well I would not change anything. .
