Here's why:

* Upwarping is a geological process where a large area of the Earth's crust is pushed upwards by forces from below. This can be caused by the movement of tectonic plates, magma intrusions, or other geological events.

* The upward force doesn't always cause a sharp, jagged mountain range. Instead, it can create a broad, gently sloping dome or plateau.

Some examples of upwarped mountains are:

* The Black Hills of South Dakota are a classic example of a dome-shaped upwarp.

* The Adirondack Mountains of New York are another example, although they have been eroded over time, giving them a more rugged appearance.

In contrast to folded mountains, which are formed by the compression of rock layers, upwarped mountains are created by a more gradual uplift process. This leads to their characteristic broad, rounded shapes.