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How are mountains formed? -

Mountains can come into existence in a number of ways, but they always involve plate tectonics, or the shifting and collision of the massive plates that move just beneath the earth's surface.

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How are mountains formed? -

Volcanic mountains are formed when tectonic shifts push molten magma to the surface, where it then cools and solidifies. Japan's Mount Fuji is an example of this.

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How are mountains formed? -

The most common type of mountain is called a fold mountain, which is caused by the collision of two tectonic plates. The softer, less dense material is pushed up to the surface to form mountain ranges and plateaus, while the more dense material is pushed down deeper into the earth's mantel. This is how ranges such as the Himalayas and the Rockies were formed.

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How do geologists age mountains? -

Determining the age of mountains was a long-impossible feat that stumped even the most accomplished scientists and geologists. That is until around the 17th century, when the field of stratigraphy began to rise to prominence.

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How do geologists age mountains? -

Using stratigraphy, which is the study of the strata, or layers, of rock formation, the age of mountains can be determined by comparing these strata to one another to determine when a given mountain took its current shape, based on the materials and sediments present. So, thanks to geologists, we now know which ranges on earth are the oldest.

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Massif Central -

One of the oldest mountain and highland regions in Europe, the Massif Central of southeastern France is at least 60 million years old, assumed to be formed when the European and African tectonic plates once collided.

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Massif Central -

While entirely dormant today, the widespread area is dotted with around 450 extinct volcanoes that were all formed during the massive, ancient clash of the continents.

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Aravalli Range -

The oldest mountain range in India, and one of the oldest in the world, the Aravalli Range stretches 430 miles (some 690 km) across southwestern India.

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Aravalli Range -

The Aravallis are believed to date back to the Proterozoic era, making them around 350 million years old. Evidence of some of the earliest civilizations on the Indian subcontinent lay in the lush Aravalli mountains and foothills.

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Blue Ridge Mountains -

The Blue Ridge Mountains, arguably the most beautiful stretch of the North American East Coast's Appalachian Mountains, is also the oldest stretch, at 1.2 billion years old.

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Blue Ridge Mountains -

True to their name, the Blue Ridge Mountains really do glow blue when observed from a distance. This is because of a particular hydrocarbon called isoprene that is emitted by the beautiful oak and aspen trees. When viewed from a distance, this hydrocarbon appears as the unique, dreamlike blue haze that surrounds the Blue Ridge Mountains.

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Mount Pilanesberg -

Many of the earth's oldest mountains rest in South Africa, and one of these is Mount Pilanesberg. The oldest volcanic mountain formation in Africa, and one of the oldest in the world, Mount Pilanesberg is 1.2 billion years old.

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Mount Pilanesberg -

Mount Pilanesberg has been inactive for quite some time, with its most recent eruption occurring around 1,200 million years ago. Numerous platinum mines operate at the base of the mountain.

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St. Francois Mountains -

The St. Francois Mountains that run through the otherwise mostly flat prairie state of Missouri are the oldest volcanic mountains in the United States, dating back nearly 1.5 billion years.

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St. Francois Mountains -

While the St. Francois Mountains are quite modest in stature, with the highest peak resting only 1,772 feet (540 m) above sea level, the beautiful igneous rock formations that seem to melt down its slopes make this range a popular destination for outdoor enthusiasts.

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Black Hills -

The Black Hills of South Dakota and Wyoming have been considered holy by a number of Native American tribes since the beginning of human settlement in the area.

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Black Hills -

These fold mountains, with their characteristic abrupt and dramatic rock formations that seem to burst from the earth, are 1.8 billion years old, making them the oldest mountains in North America.

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Guiana Highlands -

At two billion years old, the Guiana Highlands range are not only the oldest mountains in South America, but in all of the Americas from Canada to Chile.

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Guiana Highlands -

Situated at the northern tip of the continent, the Guiana Highlands stretch 1,200 miles (1,930 km) across Venezuela, the Guianas, Northern Brazil, and southern Colombia.

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Magaliesberg -

Known simply as the Magaliesberg, this modest and beautiful range is located in the northernmost tip of South Africa and was once partially submerged, back in the days of Pangea.

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Magaliesberg -

The Magaliesberg are about 2.3 billion years old, and are a treasure to nature enthusiasts and conservationists around the world. Southward-facing quartzite cliffs and pristine waterfalls make the Magaliesberg a magnificent reminder of the earth's ancient past.

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Karijini Range -

The Karijini Range in Australia is more commonly referred to in modern times as the Hamersley Range, named after the wealthy Australian colonialist who funded the expedition that led to the European discovery of the mountain range.

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Karijini Range -

The Karijini Range is the second oldest range in the world, dating back 3.4 billion years ago. Located in Australia's North West, these mountains are rich in iron, and for a time produced about 90% of the iron for the entire country.

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Waterberg Mountains -

The Waterberg Mountains in northern South Africa stretch over 90 miles (150 km) from east to west, and are a mind-boggling 2.7 billion years old. The range is a UNESCO-protected biosphere.

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Waterberg Mountains -

Scattered throughout the Waterberg Mountains are remnants of the very beginnings of human history, including cave art that dates back to the Stone Age. Some experts also believe this was the birthplace of some of modern humans' earliest ancestors.

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Barberton Greenstone Belt -

The Barberton Greenstone Belt in South Africa, traditionally known as the Makhonjwa Mountains, take the cake as the oldest mountain range in the world. These fold mountains are thought to have slowly burst from the earth around 3.6 billion years.

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Barberton Greenstone Belt -

After billions of years of wind and rain erosion, the peaks of the Greenstone Belt no longer scratch the sky as they once did. Today, the highest point in the range reaches over 5,900 feet (1,800 meters) above sea level.

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Himalayas -

Now that we've had a look at the oldest mountain ranges in the world, what about the youngest? The youngest, and by far the tallest, mountain range in the world, is the awe-inspiring Himalayas of South Asia.

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Himalayas -

The Himalayas were formed around 40 million years ago by the dramatic and catastrophic collision of the Indian and Eurasian landmasses. These mountains are so young, in fact, that they are still growing taller, by a rate of nearly half an inch (2.5 cm) a year.

Sources: (World Atlas) (Oldest.org) (National Geographic)

See also: The most picturesque mountain towns in America

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