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 September 2, 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 September 2, 2014).

Share This




More Earth & Climate News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands of Fish Dead in Mexico Lake

Raw: Thousands of Fish Dead in Mexico Lake

AP (Sep. 2, 2014) — Over 53 tons of rotting fish have been removed from Lake Cajititlan in western Jalisco state. Authorities say that the thousands of fish did not die of natural causes. (Sep. 2) Video provided by AP
Powered by NewsLook.com
Raw: Iceland Volcano Spewing Smoke

Raw: Iceland Volcano Spewing Smoke

AP (Sep. 2, 2014) — The alert warning for the area surrounding Iceland's Bardarbunga volcano was kept at orange on Tuesday, indicating increased unrest with greater potential for an eruption. Smoke is spewing from the volcano, and lava is spouting nearby. (Sept. 2) Video provided by AP
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Halliburton Reaches $1B Gulf Spill Settlement

Halliburton Reaches $1B Gulf Spill Settlement

AP (Sep. 2, 2014) — Halliburton's agreement to pay more than $1 billion to settle numerous claims involving the 2010 BP oil spill could be a way to diminish years of costly litigation. A federal judge still has to approve the settlement. (Sept. 2) 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