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 Lego-like wall produces acoustic holograms
17.10.2016 | Duke University

nachricht New evidence on terrestrial and oceanic responses to climate change over last millennium
11.10.2016 | University of Granada

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>