The massive tectonic collision that is causing the Himalayas to rise could also split Tibet apart, with the Indian Plate potentially breaking in two, sliding under the Eurasian Plate and tearing Tibet apart. The colorful swirls and streaks that characterize China’s Rainbow Mountains would go unnoticed if not for the massive tectonic collision that created the Himalayas. Also, the Arabian and Eurasian Plates are still converging, and recent research suggests that a chunk of oceanic crust that separated the two plates before they collided is now being torn apart under Iraq and Iran.
Tibet may be tearing in two beneath the rising Himalayas, with chunks of the continental plate peeling off, researchers have found. The geology beneath the world’s tallest mountain range may be even more complex than previously thought, according to a new study presented at the annual meeting of the American Geophysical Union and published as a peer-reviewed preprint online.
The Himalayas are rising because two continental tectonic plates, the Indian and Eurasian, are colliding beneath the colossal mountain range. When oceanic and continental plates collide, the denser oceanic plate slides beneath the lighter continental plate in a process called subduction. However, when two equally dense continental plates collide – as is the case beneath the Himalayas – it is not easy to predict which plate will end up beneath the other, and geologists are still not sure what is happening in Tibet.
Mountains of Tibet. SnowLion Tours
Some suggest that the main part of the Indian plate may simply slide under the Eurasian plate without sinking deeply into the mantle, a process called underplating; others believe that perhaps the deeper parts of the Indian plate are subducting while the upper parts are stubbornly wedged into the main part of Tibet.
A new study suggests that the answer may be both. The researchers found evidence that the Indian plate is subducting, but in doing so, it is deforming and tearing, with its top half peeling off, or delaminated.
“We didn’t know that continents could behave like this, and for Earth science it’s quite fundamental,” Douwe van Hinsbergen, a geodynamicist at Utrecht University in the Netherlands who was not involved in the work, told Science Magazine.
To get a clearer picture of what’s going on beneath Tibet, the researchers studied earthquake waves traveling through the crust where the two plates collided. They reconstructed images of these waves to show what look like ruptures in the crust of the Indian Plate. In some places, the bottom of the Indian Plate is 124 miles (200 kilometers) deep, Science Magazine reports. In other places, the bottom of the plate is only 62 miles (100 kilometers), suggesting that part of it has peeled away.
Previous work published in 2022 in the journal PNAS also showed changes in the types of helium emerging from geothermal vents in the region. One form of helium, known as helium-3, is found in mantle rocks, while helium with lower concentrations of helium-3 likely comes from the crust. By mapping helium changes in multiple vents, the researchers found a boundary where the two plates currently meet north of the Himalayas. The results of these geochemical studies confirm that the earthquake wave data hint at a plate breakup, the researchers wrote.
The new study may also point to areas of high earthquake risk along plate boundaries, according to Science, although researchers don’t yet fully understand how ruptures and deformations deep within the Earth’s crust lead to stress buildup at the surface.
Rainbow Mountains: China’s Psychedelic Landscape Formed by the Collision of Two Tectonic Plates. The colorful swirls and streaks that characterize China’s Rainbow Mountains would go unnoticed if not for the monumental tectonic collision that created the Himalayas.
As the name suggests, China’s Rainbow Mountains are multi-colored formations in the northwest of the country. The landscape in this region is otherworldly, with bright stripes that look like they were spray-painted on the rocks.
The Rainbow Mountains are located in the foothills of the rugged Qilian Mountains and likely formed around the same time as the Himalayas, about 50 million years ago, according to NASA’s Earth Observatory. The land, which was once relatively flat, was crumpled and folded into a jagged terrain when the Indian tectonic plate collided with the Eurasian plate. This happened because the plates have similar rock densities, so neither could slide under the other to form a subduction zone, according to the U.S. Geological Survey (USGS).
Coloured Mountains of Zhangye Danxia, China. airpano.ru
But the foundation for the rainbow pattern of the mountains was laid long before the epic collision. The rainbow mountains are made of sandstone and siltstone, sedimentary rocks that form when sand and silt, respectively, are compacted and cemented together over long periods of time. These rocks, with their bands of different colors, were deposited before the Himalayas were formed.
The colorful streaks are the result of iron and other trace elements in the stone. Each streak has a different composition, which determines its pigment. For example, the dark red streaks are rich in iron oxides, the yellow layers contain abundant iron sulfide, and the green streaks contain more chlorite and iron silicates, according to a 2016 article in Forbes.
Iron and other minerals accumulated in the rock while the sand and silt grains were still held together. Groundwater circulating in the pore spaces between the grains deposited the minerals, coating each grain and further gluing the rocks together.
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The slanted stripes we see today on the slopes of the Rainbow Mountains are inverted layers that would have remained buried and horizontal if the Indian and Eurasian plates had not smashed into each other. The compression of the land by plate tectonics was followed by intense erosion that erased any sediment covering the colorful layers. Fortunately for modern visitors, there is no vegetation to obscure the striking rainbow patterns.
The Rainbow Mountains are a popular tourist attraction. They are protected as part of the Zhangye Danxia National Geopark, but visitors can climb to the top of the hills and admire the view using wooden ladders and platforms.
The folded rocks of Iran are a colorful formation that is part of the Greater Caucasus Mountains, which were formed when the Eurasian tectonic plate collided with the Arabian plate millions of years ago.
The folded rocks of Iran are rugged mountain ranges and valleys southwest of the Caspian Sea. They are an extension of the Greater Caucasus mountain belt, which also runs along Russia’s border with Georgia and Azerbaijan.
The folded cliffs of Iran, as seen from a satellite in 2025. The green line curving down from the top of the image is the Kezel Ozan River. Near the top of the image, a line cutting through the folded cliffs shows the Zanjan-Tabriz Highway (Highway 2). Imagery ©2025 Airbus, CNES/Google maps
The folded rocks are located at the intersection of Asia and Europe, where major tectonic forces converge. The rocks are formed by countless sedimentary layers that were uplifted and folded into the landscape we see today during the initial collision of the Arabian and Eurasian tectonic plates. The timing of this collision is hotly debated, with estimates ranging from 10 million to 50 million years ago.
“The tectonic collision of Eurasia and Arabia over millions of years compressed these colorful rock layers, bending them into large folds,” NASA officials wrote on the social platform X in January 2024.
The Arabian and Eurasian plates are still converging, and recent research suggests that a chunk of oceanic crust that separated the two plates before they collided is now being pulled apart beneath Iraq and Iran. The Neotethys oceanic plate appears to be pulling the region down from below, causing unusual sediment accumulation on the surface.
Iran’s folded rocks are millions of years old, formed when the Eurasian and Arabian tectonic plates collided. Satellite image from 2023. NASA Earth Observatory
Iran’s folded rocks are colorful, with vibrant terracotta, greenish, and bluish streaks that are the result of different sedimentary layers laid down over time. These layers have been eroded away over millions of years since the initial tectonic collision, revealing the alternating colors and textures of the underlying rocks.
Satellite images of folded rocks show the extent to which the landscape has been compressed over the eons. Scientists at NASA’s Jet Propulsion Laboratory colored one such image with infrared light to show the different layers of rock, as well as vegetation and the man-made Zanjan-Tabriz Highway, which cuts through the folded rocks and connects the cities of Tehran and Tabriz.
Another satellite image from NASA’s Earth Observatory highlights the complexity of the Earth’s surface in the region, showing the Kezel Ozan River, which flows through the southeastern corner of the folded rocks and supplies water for agriculture in the area.
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