Which of the following is not a volcanic feature?

Step 1: Analyze the question We need the option that is NOT associated with volcanic activity.

Step 2: Review each option

• A. Caldera: A large basin-shaped depression formed when a volcano collapses after an eruption or when its summit is blown off. It is a volcanic feature.
• B. Geyser: A hot spring that periodically shoots out hot water and steam. It is found in areas of volcanic (geothermal) activity, such as Yellowstone in the USA and Iceland, so it is a volcanic feature.
• C. Dyke: An intrusive igneous feature. Magma cuts across the layers of rock and hardens vertically or steeply. It is a volcanic (intrusive) feature.
• D. Ventifact: A rock that has been shaped, polished, or faceted by wind-blown sand. This is a feature of wind (aeolian) erosion in deserts, not of volcanic activity.

Step 3: Answer The only option that has nothing to do with volcanism is Ventifact.

Tip: Link the word to its process. "Vent" in ventifact might tempt you to think of a volcanic vent, but ventifacts come from wind abrasion. Remember desert features: ventifacts, yardangs, zeugen, deflation hollows, and inselbergs. Volcanic and intrusive features include calderas, craters, dykes, sills, batholiths, and geysers.