Topic 1 - Describe what occurs at a divergent plate boundary. What happens at a transform plate boundary? Compare and contrast the types of processes that can occur at a convergent plate boundary.

Question

Topic 2 - List five factors that can influence how long global supplies of a given mineral will last, and explain how each might increase or decrease the time span the mineral will be available to us.

Answer 1

Topic 1:

At a divergent plate boundary, two tectonic plates move away from each other. This movement creates a gap, which causes magma from the mantle to rise up and fill the space between the two plates. As the magma cools and solidifies, it forms new oceanic crust. This process is known as seafloor spreading and occurs along mid-ocean ridges.

At a transform plate boundary, two tectonic plates slide past each other. Unlike at divergent and convergent plate boundaries, there is no creation or destruction of crust. Instead, the plates grind and scrape against each other, causing earthquakes. The San Andreas Fault in California is an example of a transform plate boundary.

At a convergent plate boundary, two plates move towards each other. The type of boundary and the direction of movement determine the type of processes that occur. There are three types of convergent plate boundaries: oceanic-oceanic, oceanic-continental, and continental-continental.

At an oceanic-oceanic convergent plate boundary, one oceanic plate subducts beneath another, forming a deep-sea trench. The subducting plate melts as it descends into the mantle, creating magma that rises to the surface, forming volcanoes on the overlying plate. Over time, this process can lead to the formation of island arcs.

At an oceanic-continental convergent plate boundary, an oceanic plate subducts beneath a continental plate. This can create a volcanic arc on the continental side of the subduction zone, such as the Andes in South America. Continental-continental convergent plate boundaries result in the formation of mountain ranges like the Himalayas.

Topic 2:

1. Consumption rate: The faster a mineral is consumed, the shorter the lifespan of the global supply. This can be influenced by changes in demand from industries, population growth, and technological advancements.

2. Resource quality: Lower quality deposits are more expensive and difficult to extract, which can decrease the lifespan of the global supply.

3. Exploration and discovery: Exploration efforts can lead to the discovery of new deposits, while lack of exploration can limit supplies and decrease the lifespan of the global supply.

4. Recycling and substitution: Increased recycling and the development of alternative materials can extend the lifespan of the global supply.

5. Political and economic instability: Political unrest, war, and changes in trade policies can disrupt the supply chain and limit access to mineral resources, which can decrease the lifespan of the global supply.