Which of the following is not an intrusive volcanic landform?

Question

Accepted Answer

The correct option is 2:

A Caldera is correctly identified as a landform that is not intrusive. Intrusive landforms, also known as plutonic landforms, are created when magma cools and solidifies beneath the Earth's surface, remaining hidden until exposed by erosion. A Caldera, however, is a large, basin-shaped depression formed when a volcano erupts and the roof of the magma chamber collapses inward, usually following an extremely violent eruption. Since a Caldera is a feature visible on the surface, directly resulting from explosive surface (extrusive) volcanic activity and subsequent collapse, it is classified as an extrusive or a volcano-tectonic landform, not an intrusive one.

The incorrect option is 1 (Batholith):
A Batholith is a massive body of igneous rock that forms when magma cools deep beneath the Earth's surface. It is the largest type of intrusive igneous body, often forming the core of mountain ranges. Because the magma cools and solidifies slowly within the Earth's crust, the Batholith is fundamentally an intrusive volcanic landform.

The incorrect option is 3 (Dyke):
A Dyke is a vertical or near-vertical sheet-like body of igneous rock that cuts across existing rock layers. Dykes are formed when magma forces its way into fractures and fissures and then solidifies underground. Since the formation process involves magma intruding into surrounding rock layers before cooling, a Dyke is classified as an intrusive feature.

The incorrect option is 4 (Sill):
A Sill is a flat, sheet-like body of igneous rock that is parallel to the surrounding rock layers. Like Dykes, Sills form when magma is injected between sedimentary or metamorphic layers and cools beneath the surface. This lateral intrusion and subsequent underground solidification categorize the Sill as a clear example of an intrusive volcanic landform.