Science Olympiad Dynamic Planet Practice Test

Which feature develops as a linear zone where the Earth’s crust is being pulled apart?

1. Foreland basin

2. Rift basin

3. Intermountain basin

4. Backarc basin

The correct answer is: Rift basin

A rift basin is formed in a linear zone where the Earth's crust is being pulled apart due to tectonic forces, often associated with divergent plate boundaries. This stretching and thinning of the crust creates a series of faults that cause portions of the crust to drop down relative to surrounding areas, leading to the development of a basin. As this process occurs, it typically results in the formation of low-lying areas that can eventually be filled with sediment and may also evolve into larger geological features like rivers and lakes. In contrast, other options represent different geological features influenced by varying tectonic processes. A foreland basin typically forms adjacent to mountain ranges where sediment accumulates due to the weight of the uplifted terrain. An intermountain basin occurs between mountain ranges and often develops in regions where tectonic forces are compressing the earth's crust, leading to uplift. A backarc basin forms behind a volcanic arc, typically as a result of subduction, where the extension occurs due to the dynamics of tectonic plates being pulled apart from the volcanic activity. Each of these features has distinct processes and characteristics that differentiate them from a rift basin.