Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Humans dwelt in Ice-Age Tibet

27.03.2002


Humans were living in the Tibeatan mountains 16,000 years earlier than scientists had thought.
© Bill Bachmann/Alamy


Footprints and a fire found from 20,000 years ago.

Handprints and footprints 20,000 years old reveal that people lived on the Tibetan plateau at the height of the Ice Age - 16,000 years earlier than scientists had thought. The newly found signs of life cast doubt on the idea that a glacier a kilometre thick covered the plateau at that time.

David Zhang and S. H. Li of the University of Hong Kong found the marks of at least six individuals, including two children, in marble-like rocks that were once soft mud on a mountain slope 85 kilometres from the Tibetan capital, Lhasa1.



They also found a fireplace nearby, with the remains of a primitive stove, suggesting that the site was a camp, perhaps even a settlement.

Until now, the oldest known settlements on the Tibetan plateau dated from late Neolithic times, around 4,000 years ago. This had led some researchers to conclude that humans first migrated into Tibet around this time.

The encampment is also a nail in the coffin for the ice-covered plateau hypothesis. It indicates that at least part of the plateau, which today is 4,000 metres high on average, was free of ice even during this frigid period of Earth’s history.

Carbonate cast

The very hot spring that probably attracted the Ice-Age settlers also preserved their marks for posterity. The spring water is rich in dissolved minerals and gases. As carbon dioxide gas bubbles out of the water, minerals such as calcite precipitate out. This forms a soft mineral mud. As the mud dries, it turns into a hard, durable limestone called travertine.

So, thanks to the hot spring, the mountainside made plaster casts of the Ice-Age people who lived on it. Nineteen hand- and footprints are clearly visible in the stone surface.

Zhang and Li date the travertine deposit by the tiny grains of quartz that got trapped within it while the mud solidified. Quartz acts as a mineral clock. When heated, it emits light in proportion to the time that has elapsed since it was last warmed or exposed to sunlight.

This technique is called thermoluminescence dating. Energy builds up in trapped quartz because it is exposed to radiation from natural radioactive elements such as uranium and thorium in surrounding minerals. It emits this energy as light: the longer the exposure time, the higher the energy and so the brighter the light.

Because heat or sunlight releases the trapped energy, the quartz grain clock would have been set to zero when the grains became embedded in the warm mud from the spring.

References

  1. Zhang, D.D. & Li, S. H.Optical dating of Tibetan human hand- and footprints: an implication for the palaeoenvironment of the last glaciation of the Tibetan Plateau. Geophysical Research Letters, 29, Published online DOI: 10.1029/2001GL013749 (2002).


PHILIP BALL | © Nature News Service

More articles from Interdisciplinary Research:

nachricht Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs
07.11.2017 | Technische Universität München

nachricht NRL clarifies valley polarization for electronic and optoelectronic technologies
20.10.2017 | Naval Research Laboratory

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>