Here's a breakdown of how it works:

1. Magma Rises: Molten rock (magma) from deep within the Earth rises towards the surface.

2. Intrusion: The magma pushes up into the existing rock layers, but doesn't break through the surface.

3. Upward Pressure: The magma's pressure causes the overlying rock layers to bulge upwards, forming a dome-like shape.

4. Erosion: Over time, the rock layers at the top of the dome are eroded, exposing the underlying igneous rock.

Where do they occur?

Dome mountains can form in a variety of locations, but they are most commonly found in:

* Continental interiors: Areas away from plate boundaries, where the Earth's crust is thick.

* Volcanic regions: Areas where magma is relatively close to the surface, even if it doesn't always erupt.

Examples of dome mountains:

* Black Hills of South Dakota (USA): A classic example of a dome mountain formed by a large granite intrusion.

* Henry Mountains (Utah, USA): A group of dome mountains formed by smaller, localized intrusions.

Let me know if you have any more questions!