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 August 21, 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 August 21, 2014).

Share This




More Earth & Climate News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 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