Science Olympiad Dynamic Planet Practice Test

What is an example of a geological feature that may be filled by ring dikes?

1. Mountain ranges

2. Collapsed volcanic calderas

3. Subduction zones

4. Ocean ridges

The correct answer is: Collapsed volcanic calderas

The correct answer is that ring dikes are typically found in collapsed volcanic calderas. A ring dike forms when magma rises into a fissure surrounding a volcanic structure after the primary explosive activity has led to a collapse of the central area. The structure of a ring dike is characterized by roughly circular or elliptical formations that encircle and support the flanks of a caldera, managing the internal pressures and uneven uplift that result after the caldera formation. In contrast, mountain ranges, subduction zones, and ocean ridges are not places where ring dikes are typically found. Mountain ranges are formed through tectonic processes such as folding and faulting but do not involve the specific magma-related processes that create ring dikes. Subduction zones, where one tectonic plate moves under another, do relate to volcanic activity but are not specifically associated with the formation of ring dikes. Ocean ridges, primarily sites of seafloor spreading and new oceanic crust formation, also do not exhibit this geological feature. Therefore, the unique conditions inherent in collapsed volcanic calderas make them the correct context for the formation of ring dikes.