Plate Tectonics Riley Fanning

History of Pangaea Section 1 Alfred Wegener originated the theory of Pangaea in He was a geologist from Germany, but also studied geophysics, oceanography, and paleontology. Pangaea means “all the land”, and began about 200 years ago in the Jurassic period. The theory of continental placement being discussed was that most of the continents seem to fit together like a puzzle. Harry Hess and R. Deitz published similar hypotheses based on “sea floor spreading”. This idea is basically the same as Holmes’s but now it has more evidence to develop and support the idea.

Convergent Boundaries Section 2 Convergent Boundaries is where two plates moving in opposite directions meet and one of the plates are dragged below the other. Convergent plate boundaries are typified by the Aleutian Trench, where the Pacific Plate is being dragged down by the North American Plate. Earthquakes, volcanoes, trenches and crustal deformation are characteristics of convergent boundaries. An example of a Convergent Boundary is the Andes Mountain Range. This involves the oceanic plate and the Continental Plate. _tectonics.html

Divergent Boundaries Section 3 Divergent Boundaries are when two adjacent plates pull apart which causes “sea- floor spreading” as new material is added to the oceanic plates. Earthquakes, volcanoes and a new ocean basin are things that may/will happen (depending on the area of which you live). A great example of a Divergent Plate Boundary is the Mid-Atlantic Ridge which is a submerged mountain range that extends from the Arctic Ocean to beyond Africa’s southern tip. /description_plate_tectonics.html boundaries.shtml

Transform Boundaries Section 4 A Transform Boundary is where two plates slide past one another. Earthquakes, landslides and mudslides occur and so do volcanoes, but volcanoes aren’t usually present because of magma sources of upwelling or subducting plates aren’t present. The San Andreas Fault Zone is an example of a Transform Boundary. This connects a divergent boundary (the Gulf of California) with the Cascdia Subduction Zone.

Real World Connections Section 5 We live on the North American Plate, and we are bordered by the Pacific Plate, South American Plate, Eurasian Plate, and the Arabian Plate. We are not in any serious danger, but other parts of America are. Some are California with earthquakes, and Mount. St. Helens in Washington with Volcanoes. A potential problem that may occur is the continental plates rotating/moving so much that they collide back into each other. aspx