Mountain ranges make up some of the world’s most impressive landscapes. Like earthquakes and volcanoes, they are formed as a consequence of the activity of the Earth’s tectonic plates. Where the plates push up against one another, the Earth’s crust buckles and folds, resulting in ranges of Rocky Mountains. Volcanoes also make up some of the world’s greatest mountains.
There are a few ways that mountains can form. One thing these methods have in common is that they all take millions of years!
Most mountains formed from Earth’s tectonic plates smashing together. Below the ground, Earth’s crust is made up of multiple tectonic plates. They’ve been moving around since the beginning of time. And they still move today as a result of geologic activity below the surface. On average, these plates move at a rate of about one to two inches each year.
When two tectonic plates come together, their edges can crumple. Think of what happens to an aluminum can when you crush it. It’s a bit like that! The result of these tectonic plates crumpling is huge slabs of rock being pushed up into the air. What are those called? Mountains, of course! Specifically, these are called “fold mountains.”
For example, the tectonic plates that lie underneath India and Asia crashed into each other over 25 million years ago. What happened? The Himalayas, including Mount Everest, formed. And they’re still pushing against each other. That means the Himalayas are still growing even today!
Sometimes, instead of crashing together, two tectonic plates grind against each other. Occasionally, this results in one plate lifting up and tilting over. The result? A fault-block mountain range! One example is the Sierra Nevada mountain range in California.
Other times, a unique type of mountain is made when one plate is pushed below the other, pushing magma to the surface. This is how volcanoes, like Mount Fuji, are made. Volcanic activity below Earth’s surface can also result in new mountains when magma is pushed up toward the surface. When that happens, it cools and forms hard rock. The result is dome mountains.
Mountains can also form by way of erosion. In an area with a high plateau, rivers and streams can carve away stone in the form of deep channels. Over millions of years, what is left is a mountain between deep river valleys!
Picture Credit : Google