Homework 1

Assigned Sept 30 or Oct 1

Due Oct 5 or 6

101/201: Read chapter 2 (pg 37-54) and then, in your own words, explain the theory of plate tectonics and the different type of plate boundaries (give details). Give a real world example of each type of plate boundary

The theory of plate tectonics explains that the earth’s surface is broken into several plates. These plates move around and interact with each other in various ways.

The first type of plate boundaries are known as a divergent boundaries. Divergent boundaries form primary in the the ocean and are also known as Mid-Ocean ridges. They are volcanic, and this is where oceanic crust forms. They form a very large mountain range that goes through all the worlds oceans.

The second type of plate boundary is Transform boundaries. This is where two plates slide/grind by each other. They often have large earthquakes associated with the motion. They are NOT volcanic. They primarily offset divergent boundaries but an example of where a transform boundary has moved onto the continent is the San Andreas Fault in California.

The third type of boundary is convergent boundaries. This is where two plates are coming together and there are different types depending on the type of crust involved in the collision.

Continental to oceanic crust convergence: when these two types of crust collide, the oceanic crust is forced under the continental because it is so much thinner and heavier than the continental. This process is known as Subduction and a Subduction zone forms. As the oceanic crust is pushed down, melting occurs at depth and volcanoes will form on the overriding plate in a chain known as a volcanic arc. An example is the Cascade mountains.

Oceanic to oceanic crust convergence: When two ocean plates collide, one is pushed under the other forming a Subduction zone and a chain of volcanoes on the overriding plate. This chain of volcanoes are known as an island arc chain.

Continental to Continental convergence: When two continental plates collide, neither will subduct due to density and thickness. Instead, they crumple and create VERY large non volcanic mountain such as the Himalayas

201: Explain in your own words, why mineral resources form at convergent and divergent boundaries.

Mineral resources form at convergent and divergent boundaries because of the volcanic activity. With volcanic activity, there are often fluids that have elements that won’t go into rock forming minerals. Often those element will form important ore mineral deposits such as Barite or Sulfur.