The Himalayas, one of the youngest mountain formations on the planet, it turns out, were formed not at one time, as previously thought, but in several stages. This discovery was made by Chinese and American geologists, whose research results are published in the journal Nature Geoscience. This discovery raises doubts in common theories about the formation of the Himalayan Mountains and opens new opportunities for the search for new hypotheses.
According to current ideas of scientists, the Himalayas emerged after the collision of the Eurasian tectonic plate with the Indian plate, which occurred about 50-30 million years ago. However, the exact date of the beginning of this collision and the speed at which it occurred are still unknown. It is this question that has caused controversy among scientists and became the main goal of the study.
Scientists used a chemical indicator to estimate the height of neighboring lithospheric plates and paid attention to the difference in the isotopic composition of rainwater and precipitation on the slopes of mountains and their tops. It turned out that rainwater that fell on the mountainsides contained more heavy isotopes of oxygen and hydrogen, while drops that fell on the tops contained predominantly light atoms of these elements.
With this observation, scientists were able to measure the fractions of the three oxygen isotopes in quartz samples formed in southern Tibet before the collision of the Indian and Eurasian plates. The results showed that the formation of the Himalayan Mountains took place in at least two stages.
“Many experts have long believed that it takes one powerful plate collision on the scale of entire continents to form mountain ranges like the Himalayan Mountains. Our study challenges these theories and opens up new avenues for exploring new hypotheses,” said Daniel Ibarra, a researcher at Stanford University.
The study also allowed scientists to conclude that before the collision of lithospheric plates, the future Himalayan Mountains already had a significant height. The edges of these plates rose about 3.5 kilometers above sea level, making them comparable to the Altai and Alpine mountains. This means that the formation of the Himalayan Mountains occurred not only as a result of plate collision, but also under the influence of other factors.
The findings of the study call into question common theories about the formation of the Himalayan Mountains and require a revision of the results of modeling the ancient climate and ecosystems of the region. This discovery also opens new perspectives for further research and the search for new hypotheses about the process of mountain formation.
