The answer is actually quite complex, since the height or elevation of mountain ranges in the past can be difficult to know. However, it is a very important question as mountains have a huge role in the environment.
They can disturb air flow, affect global and regional climate and provide opportunities for plants and animals to evolve. Geoscientists address questions about ancient mountain heights by looking at sedimentary basins within mountain ranges.
These are low areas where sediment materials such as pollen and plant leaves collect and minerals form in the soil. A basin today may be much higher or lower than it was when sediment entered it. If we look at fossilised pollen, we may find it comes from plants which likely grew in a particular range of elevation, and we may also notice the absence of certain other plants.
We can figure out where ancient plants likely grew by looking at their modern relatives. We can conclude the landscape was too high for plant A , high enough for plant B which gave us the pollen , but not high enough for plant C. That is a pretty powerful capability, especially if the elevation of the landscape has changed significantly since the sediment was first deposited. We can also look at the different kinds or isotopes of certain elements particularly oxygen contained in plant waxes, clays and carbonate minerals that form by chemical reactions in the soil.
These plants and minerals incorporate rainwater. As a band of rain reaches a mountain range, water with heavier oxygen isotopes falls out first. This means rainwater at higher elevations contains lighter oxygen isotopes, which then pass into the plants and minerals there. If we find sediment that was deposited into a low basin 30 million years ago, but is now much higher, it will still contain oxygen isotopes that reveal the elevation at which it first formed.
We can measure these isotopes to estimate how much higher the landscape has become. Everest is part of the Himalayas, a mountain range that stands at the southern edge of the vast Tibetan Plateau which is around km above sea level. Scientists have used the methods described above to understand the history of the plateau, which evolved as a result of several ancestral mountain ranges joining up. Why it's so hard to treat pain in infants.
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Travel A road trip in Burgundy reveals far more than fine wine. However, by 25 million years ago the fast moving Indian continent had almost entirely closed over the intervening ocean, squeezing the sediments on the ocean foor.
Since the sediments were lightweight, instead of sinking along with the plate, they crumpled into mountain ranges—the Himalayas. By 10 million years ago the two continents were in direct collision and the Indian continent, because of its enormous quantity of light quartz-rich rocks, was unable to descend along with the rest of the Indian plate. It was at about this time that the anchor chain must have broken; the descending Indian plate may have fallen off and foundered deep into the mantle.
Although we don't fully understand the mechanism of what happened next, it's clear that the Indian continent began to be driven horizontally beneath Tibet like a giant wedge, forcing Tibet upwards. Tibet, meanwhile, is behaving like a giant roadblock that prevents the Himalaya from moving northward.
Under the peaks and under most of Tibet the Indian plate is apparently gliding along almost frictionlessly. Future of the Himalaya Over periods of million years, the plates will continue to move at the same rate, which allows us to forecast fairly reliably how the Himalaya will develop. In 10 million years India will plow into Tibet a further km. This is about the width of Nepal. Because Nepal's boundaries are marks on the Himalayan peaks and on the plains of India whose convergence we are measuring, Nepal will technically cease to exist.
But the mountain range we know as the Himalaya will not go away. This is because the Himalaya will probably look much the same in profile then as it does now.
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