Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Dust could settle Himalaya debates


Great loess: layers of ancient dust give clues to mountains’ birth.
© Nature

Deserts covered Central Asia as early as 22 million years ago

The great Asian deserts developed 22 million years ago at the latest, 14 million years earlier than had been thought. So concludes a new analysis of Chinese soils, filling in another piece of the puzzle of the Himalayas’ birth.

Today, huge deserts characterize the vast landmasses inside Asia, the largest continent on Earth. Here, cut off by the Himalayas from the humidity of the Indian Ocean and far from any other seas, the climate is extreme. Winters are ice-cold, summers blazing hot and moisture scarce.

But some time between 36 and 22 million years ago, rivers flowed through these desiccated wastelands. The Himalayas had just started pushing up into the skies. And colliding continents had only recently swallowed the ancient equatorial ocean of Tethys, which had separated Eurasia from the fragments of what was once Gondwanaland.

The transition between these very different climates happened at least 22 million years ago, estimate Zhentang Guo of the Chinese Academy of Sciences and co-workers1. At two mountain sites in China’s Qinan basin, just 160 km northeast of the Tibetan plateau, the researchers found 231 layers of ancient, brownish, wind-blown dust, called loess.

The loess was deposited from 22 to 6.2 million years ago between layers of red clay. Each layer contains about 65,000 years’ worth of deposits. Such large layers imply that extensive deserts existed nearby: the Asian interior.

"The deserts would have been relatively cold, like the Gobi today, as opposed to the Sahara," explains Bill Ruddiman of the University of Virginia, one of the team. Cold, dry, winter monsoon winds transported the desert dusts to their long-term resting place.

The Qinan basin’s stripy landscape was produced by a climate of dry winter monsoons punctuated by moist summer monsoons. The reddish clay layers were produced locally during more humid periods, when weaker winter monsoons meant that desert dust didn’t make it to the Loess plateau, the researchers believe.

"To block the moisture, there must have been some sort of a mountain range in place 22 million years ago", says Jay Quade, a desert geoscientist at the University of Arizona in Tucson. The existence of the central Asian deserts 22 million years ago offers an independent perspective on the uplift of the Himalayas, the details of which are still controversial.

Before now, little was known about the region’s climate that far back in time. Most of the studies on Chinese loess have centred on the Quaternary period, less than 1.6 million years ago. Previously, the oldest reliably dated loess finds were only about 6 million years old.


  1. Guo, Z. T. et al. Onset of Asian desertification by 22 Myr ago inferred from loess deposits in China. Nature, 416, 159 - 163 , (2002).

HEIKE LANGENBERG | © Nature News Service

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>