Featured Research

from universities, journals, and other organizations

Forgotten Source For Planetary Magnetic Anomalies?

Date:
February 22, 2008
Source:
American Geophysical Union
Summary:
Anorthosites, igneous rocks rich in plagioclase feldspar, are common on the Earth, Moon, and possibly other planets. Though anorthosites are usually not considered to be strongly magnetic, researchers note that their magnetic properties could be useful in investigating mineral deposits in addition to magnetic anomalies on other planets, particularly Mars. Through investigations of three ancient anorthosite bodies in Norway, the authors find that two anorthosites have large natural remanent magnetization signatures, indicating that they contain strong signatures of the Earth's magnetic field direction that was present when the rocks crystallized roughly 1 billion years ago.

Anorthosites, igneous rocks rich in plagioclase feldspar, are common on the Earth, Moon, and possibly other planets. Though anorthosites are usually not considered to be strongly magnetic, Brown and McEnroe note that their magnetic properties could be useful in investigating mineral deposits in addition to magnetic anomalies on other planets, particularly Mars.

Through investigations of three ancient anorthosite bodies in Norway, the authors find that two anorthosites have large natural remanent magnetization signatures, indicating that they contain strong signatures of the Earth's magnetic field direction that was present when the rocks crystallized roughly 1 billion years ago.

These signatures are comparable in intensity to those found in freshly crystallized basalts. Microscopic observations reveal that, although only one body contains high levels of magnetite, all three anorthosites contain ilmenite and hematite, which are weakly magnetic minerals.

Previous research suggests that submicroscopic plates of ilmenite with hematite intergrowths interact with each other to amplify magnetic anomalies, causing the authors to conclude that anorthosites can be important sources of magnetic anomalies on Earth and perhaps on other planets.

Journal reference: Magnetic properties of anorthosites: A forgotten source for planetary magnetic anomalies? Geophysical Research Letters (GRL) paper 10.1029/2007GL032522, 2008; http://dx.doi.org/10.1029/2007GL032522

Authors: Laurie L. Brown: Department of Geosciences, University of Massachusetts-Amherst, Amherst, Massachusetts, U.S.A.; Suzanne A. McEnroe: Norwegian Geological Society, Trondheim, Norway.


Story Source:

The above story is based on materials provided by American Geophysical Union. Note: Materials may be edited for content and length.


Cite This Page:

American Geophysical Union. "Forgotten Source For Planetary Magnetic Anomalies?." ScienceDaily. ScienceDaily, 22 February 2008. <www.sciencedaily.com/releases/2008/02/080217093611.htm>.
American Geophysical Union. (2008, February 22). Forgotten Source For Planetary Magnetic Anomalies?. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2008/02/080217093611.htm
American Geophysical Union. "Forgotten Source For Planetary Magnetic Anomalies?." ScienceDaily. www.sciencedaily.com/releases/2008/02/080217093611.htm (accessed July 26, 2014).

Share This




More Earth & Climate News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virginia Governor Tours Tornado Aftermath

Virginia Governor Tours Tornado Aftermath

AP (July 25, 2014) Virginia Gov. Terry McAuliffe toured the Cherrystone Family Camping and RV Resort on the Chesapeake Bay today, a day after it was hit by a tornado. The storm claimed two lives and injured dozens of others. (July 25) Video provided by AP
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
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