The Rocky Mountains are primarily composed of metamorphic and igneous rocks. This includes types such as granite, gneiss, and schist. The formation of these mountains is rooted in tectonic activity that carried ancient oceanic crust upwards, where intense heat and pressure transformed what was once sedimentary rock into the durable and rugged mountain ranges we see today.
The presence of granite, for example, points to the ancient volcanic activity that shaped the region. This igneous rock is known for its strength and resilience, which contributes to the towering heights and steep landscapes characteristic of the Rockies. Similarly, metamorphic rocks like schist and gneiss formed under high-pressure conditions, further illustrating the dynamic geological history of these mountains.