ScienceDaily (22 October 2007)—India's lithosphere is only half as thick as others which is the reason for its high speed collision with Eurasia.

Fifty million years ago, the Indian sub-continent collided with the enormous Eurasian continent with a velocity of about 20 cm/year. Due to this collision at such high velocities the largest mountain belt on Earth, the Himalayas, was formed. (Credit: iStockphoto/Anka Kaczmarzyk)

Fifty million years ago the Indian sub-continent collided with the enormous Eurasian continent with a velocity of about 20 cm/year. With such a high velocity India was the fastest of the former parts of Gondwanaland, according to a report by a team of scientists from the GeoForschungsZentrum Potsdam (GFZ, Germany's National Lab for Geosciences) and the National Geophysical Research Institute, India, in the 18th October 2007 edition of Nature.

Due to this collision at such high velocities the largest mountain belt on Earth, the Himalayas, was formed, as was the massive Tibetan plateau.

Until 140 million years ago India was part of the supercontinent Gondwanaland. When Gondwanaland broke up, its various parts drifted apart with different velocities. Today these various parts constitute India, Africa, Australia, Antarctica and South America.

However, the question which still remained to be answered was why India was quicker and moved much further than the other parts of Gondwanaland.

A new seismological method for determining the thickness of the present-day lithospheric plates with more precision than before has been developed at GFZ Potsdam. With this method the team of researchers has found that the Indian plate is only about 100 km thick, whereas the other parts of Gondwanaland are about 200 km thick and thus about twice as thick as India.

The reason for the break up of Gondwanaland was a mantle plume that heated the supercontinent from below, thereby causing it to break. This plume may have melted the lower part of the Indian sub-continent away, thus allowing India to move faster and further than the other parts.

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Adapted from materials provided by Helmholtz Association of German Research Centres, via EurekAlert!, a service of AAAS.