The surprise of the ancient desert footprints

2002/05/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Geologia

In two deposits of the Chinese basin of Qina ancient remains of the great Asian deserts have been found. The remains are layers of loess of those times, preparations of materials transported by the wind from the desert. The analysis of these loess in the basin has confirmed that 22 million years ago it had already disappeared. Therefore, the deserts of Asia are 14 million years older than was thought.

Finding remains of ancient deserts means that the Himalayas had already been formed, since deserts are a direct consequence of the mountain range: The mountain range of the Himalaia hinders the passage of the fogs of rain coming from the sea. When they meet the mountains, the mists are emptied and the rainwater is left on that slope of the mountains. In this way, the post-mountain lands are dried up and finally become deserts.