Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mountain-building process much faster – and cooler – than previously thought

30.06.2005


New ’cold crust’ model may help explain other Earth-shaping events



Geologists at Queen’s University have discovered that the time it takes for mountain ranges to form is millions of years shorter than previously thought. This controversial finding could have implications for our understanding of other geological processes that shaped the Earth, says Professor James Lee and postdoctoral fellow Alfredo Camacho of Queen’s Geological Sciences and Geological Engineering Department.

The study will appear in the June 30 edition of the international journal Nature.


Other members of the team are Bastiaan J. Hensen from University of New South Wales, and Jean Braun from Université de Rennes, France.

Using state-of-the-art techniques to measure the age of rocks, the researchers deciphered a pattern of ages within single crystals from rock remnants that survived continental collision. Their measurements show a 13-million-year cycle in which rocks are buried to 60 km depth, then returned to the surface. This occurred 425 million years ago during a large-scale mountain-building event called the Caledonian Orogeny.

"We were excited to be able to show, for the first time, that the duration of an orogenic’ cycle [burying, then bringing rocks to the surface] is much shorter than was previously believed – only 13 million years in this case," say Drs. Camacho and Lee. "Geologically speaking, that is a very short period indeed – a mere drop in the bucket of the Earth’s history." The duration of many geological processes that shape the Earth has been thought to last for hundreds of millions of years.

The study also suggests that the buildup of heat previously thought to be widespread during mountain building may instead be related to short-term events caused by either pulsed injection of hot fluids and/or friction on faults, with the overall crust remaining relatively cool. The study focused on the Caledonian Orogeny in Norway, where injections of hot fluids caused rapid fracturing of this cool crust, producing deep-seated continental earthquakes.

"By coupling geochronology with fundamental physical and mathematical principles and computer modeling, we can assess the durations of a variety of geological processes for the very first time," says Dr. Lee. "The new quantitative technique that we developed allows us to measure the duration of thermal disturbances at all scales, from small-scale intrusions of molten rocks into the crust (e.g. volcanoes) to large-scale orogenic cycles."

This unique "cold-crust" model stems from a new quantitative technique integrating geo-chronology, mathematics, physics, and basic geological principles. "It neatly explains many previously puzzling geological observations and may be relevant to other mountain-building events around the world," says Dr. Lee.

Nancy Dorrance | EurekAlert!
Further information:
http://www.queensu.ca

More articles from Earth Sciences:

nachricht Early organic carbon got deep burial in mantle
25.04.2017 | Rice University

nachricht New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>