Which one among the following is not intrusive feature?

Question

Accepted Answer

Lava plug is not an intrusive feature because it is an extrusive volcanic feature. Intrusive features are formed when magma cools and solidifies *beneath* the Earth's surface. Extrusive features are formed when lava erupts *onto* the Earth's surface and cools. A lava plug (also called a volcanic neck) forms when magma solidifies within the vent of a volcano. After erosion removes the outer cone of the volcano, the solidified plug is exposed at the surface.

Here's why the other options are incorrect:

*   **Sill:** A sill is a tabular (sheet-like) intrusive igneous rock body formed when magma intrudes *between* layers of existing rock. It is definitely an intrusive feature.

*   **Laccolith:** A laccolith is a mushroom-shaped intrusive igneous rock body that forms when magma intrudes *between* layers of rock and pushes the overlying layers upward, creating a dome-like structure. It is an intrusive feature.

*   **Batholith:** A batholith is a large, irregular-shaped intrusive igneous rock body that forms deep within the Earth's crust. It is a major intrusive feature, often forming the core of mountain ranges.