Here's why:

* Terrane accretion involves the addition of crustal fragments (terranes) to a continental margin.

* These terranes often carry their own unique geological features, including sedimentary rocks, volcanic rocks, and even pieces of older mountains.

* As the terrane collides with the continental margin, the pressure and heat cause the rocks to fold and deform.

* This folding process creates mountain ranges with distinct structures and compositions.

Examples of mountain ranges formed by terrane accretion include:

* The Coast Mountains in western North America

* The Himalayas (though the collision of the Indian subcontinent with Asia is a more complex process)

* The Sierra Nevada (formed by a combination of terrane accretion and other processes)

It's important to note that terrane accretion is just one way mountains can form. Other mechanisms include:

* Volcanic activity

* Faulting and uplift

* Erosion

However, when it comes to mountains directly resulting from the process of terrane accretion, folded mountains are the most common outcome.