Science Olympiad Dynamic Planet Practice Test

What distinguishes a Peripheral foreland basin during plate collision?

1. It occurs on the overriding plate

2. It occurs on the underthrust plate

3. It is characterized by volcanic activity

4. It is always smaller than retroarc basins

The correct answer is: It occurs on the underthrust plate

In the context of plate tectonics and the formation of basins during continental collision, a Peripheral foreland basin forms on the underthrust plate. This is significant because as two tectonic plates collide, the stress and pressure lead to a variety of geological processes. The underthrust plate is typically where sediment can accumulate as it is pushed down under the overriding plate, creating a basin that receives sediments from the eroding mountains formed by this collision. These basins are positioned adjacent to mountain ranges, often capturing sediments that are released from the uplifted areas, which can include debris from the overriding plate. This accumulation can also be influenced by the tectonic processes occurring at the plate boundary, which can vary depending on the nature of the collision. In contrast, the other choices describe different geological phenomena. For example, while a foreland basin can be associated with volcanic activity, it is not characterized by it in the same way that a magmatic arc might be during subduction. The size comparison to retroarc basins is also unhelpful in defining a Peripheral foreland basin, as their size can vary greatly depending on the specific geological settings and contexts.