Featured Research

from universities, journals, and other organizations

Birth of Earth's continents: New research points to crust stacking, rather than upwelling of hot material

Date:
September 16, 2013
Source:
University of Calgary
Summary:
New research provides strong evidence against continent formation above a hot mantle plume, similar to an environment that presently exists beneath the Hawaiian Islands.

New research led by a University of Calgary geophysicist provides strong evidence against continent formation above a hot mantle plume, similar to an environment that presently exists beneath the Hawaiian Islands.

The analysis, published this month in Nature Geoscience, indicates that the nuclei of Earth's continents formed as a byproduct of mountain-building processes, by stacking up slabs of relatively cold oceanic crust. This process created thick, strong 'keels' in Earth's mantle that supported the overlying crust and enabled continents to form.

The scientific clues leading to this conclusion derived from computer simulations of the slow cooling process of continents, combined with analysis of the distribution of diamonds in the deep Earth.

The Department of Geoscience's Professor David Eaton developed computer software to enable numerical simulation of the slow diffusive cooling of Earth's mantle over a time span of billions of years.

Working in collaboration with former graduate student, Assistant Professor Claire Perry from the Universite du Quebec a Montreal, Eaton relied on the geological record of diamonds found in Africa to validate his innovative computer simulations.

"For the first time, we are able to quantify the thermal evolution of a realistic 3D Earth model spanning billions of years from the time continents were formed," states Perry.

Mantle plumes consist of an upwelling of hot material within Earth's mantle. Plumes are thought to be the cause of some volcanic centres, especially those that form a linear volcanic chain like Hawaii. Diamonds, which are generally limited to the deepest and oldest parts of the continental mantle, provide a wealth of information on how the host mantle region may have formed.

"Ancient mantle keels are relatively strong, cold and sometimes diamond-bearing material. They are known to extend to depths of 200 kilometres or more beneath the ancient core regions of continents," explains Professor David Eaton. "These mantle keels resisted tectonic recycling into the deep mantle, allowing the preservation of continents over geological time and providing suitable environments for the development of the terrestrial biosphere."

His method takes into account important factors such as dwindling contribution of natural radioactivity to the heat budget, and allows for the calculation of other properties that strongly influence mantle evolution, such as bulk density and rheology (mechanical strength).

"Our computer model emerged from a multi-disciplinary approach combining classical physics, mathematics and computer science," explains Eaton. "By combining those disciplines, we were able to tackle a fundamental geoscientific problem, which may open new doors for future research."

This work provides significant new scientific insights into the formation and evolution of continents on Earth.


Story Source:

The above story is based on materials provided by University of Calgary. Note: Materials may be edited for content and length.


Journal Reference:

  1. David W. Eaton, H. K. Claire Perry. Ephemeral isopycnicity of cratonic mantle keels. Nature Geoscience, 2013; DOI: 10.1038/ngeo1950

Cite This Page:

University of Calgary. "Birth of Earth's continents: New research points to crust stacking, rather than upwelling of hot material." ScienceDaily. ScienceDaily, 16 September 2013. <www.sciencedaily.com/releases/2013/09/130916122133.htm>.
University of Calgary. (2013, September 16). Birth of Earth's continents: New research points to crust stacking, rather than upwelling of hot material. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2013/09/130916122133.htm
University of Calgary. "Birth of Earth's continents: New research points to crust stacking, rather than upwelling of hot material." ScienceDaily. www.sciencedaily.com/releases/2013/09/130916122133.htm (accessed September 19, 2014).

Share This



More Earth & Climate News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins