African rocks record ancient magnetic field
2010-05-05 0:00

By Jonathan Amos | BBCNews.co.uk


Scientists have managed to push back the date for the earliest known presence of a magnetic field on Earth by about 250 million years.

The evidence is seen in tiny iron minerals that are aligned inside ancient dacite rocks from the Barberton mountains in South Africa.

Analysis of the 3.45-billion-year-old minerals indicates the strength the field was much weaker than today.

Earth’s magnetic field protects all life on the planet.

It forms a shield that deflects harmful particles from the Sun around our world, and limits the ability of this "solar wind" to erode our atmosphere.
The new work by Professor John Tarduno, from the University of Rochester, US, and colleagues has been discussed at a major Earth sciences meeting in Vienna, Austria.

"Earth’s magnetic field is important to us," Professor Tarduno told the European Geosciences Union meeting.

"[3.45 billion years ago] is a really critical time because it’s when we start seeing the first tentative signs of life, so perhaps these two things are linked together."

The Rochester team has developed techniques for studying tiny magnetite minerals trapped inside the crystals of volcanic rock.

These minerals orientate themselves with respect to the Earth’s magnetic field in a cooling magma and lock their positions once the temperature in the host rock dips below 580C.

The Barberton samples indicate the nascent field was considerably weaker than today’s protective shield.

Whereas the modern boundary between our planet’s magnetosphere and the solar wind might be located ordinarily at about 10 Earth radii, the ancient boundary would have been much closer - perhaps three to five Earth radii, said Professor Tarduno.

He explained that one likely effect of this would have been the production of polar lights, or auroras, at much lower latitudes as many more solar particles breached the shield to collide with atmospheric molecules.

It probably also meant the atmosphere lost more of its lighter elements, like hydrogen, faster than had previously been supposed, argued Professor Tarduno.


The Barberton greenstone belt preserves some of the oldest rocks on the planet.

"What that means in an evolutionary sense to us - and this is just speculation but something we want to follow it up - is that perhaps this is suggesting the Earth was much more water-rich very early on," he said.
"If, even with this magnetic field, we are losing hydrogen and water, that would suggest the palaeo-Earth in its infant state must have had more water than we think about today."

Professor Tarduno’s team is now looking back still deeper into the past for evidence of a global magnetic field.

The field is generated by convection currents in the molten-iron outer-core of the planet, and finding evidence of an even more ancient field would say much about the interior state of the young Earth.

There are volcanic rocks in Africa, India and Australia that possibly retain a record that is 3.6bn years old.

"To go back even further in time, however, we don’t have the rocks available. But what we do have is certain younger sedimentary rocks that record minerals which were eroded from more ancient rocks - as old as four billion years old," Professor Tarduno told BBC News.

"We are developing techniques and we believe we can actually record the Earth’s magnetic field in these minerals also."


Article from: news.bbc.co.uk




2012: Leaks Found in Earth’s Magnetic Field

Video from: YouTube.com

Origin of Earth’s Magnetic Field

Video from: YouTube.com



Also tune into:

Walter Cruttenden - Lost Star of Myth and Time, Rise and Fall of Civilization and Consciousness

Walter Cruttenden - Sirius, The Binary Star & Precession

Rens van der Sluijs - Plasma Mythology & The Axis Mundi

Wallace Thornhill - The Electric Universe

William Henry - The Apotheosis is at Hand, NWO, COP15, Norway Blue Spiral & Stargates

Edmund Marriage - Global Catastrophe, Restart of Civilization & The Anu-Nagi (The Shining Ones)




Related Articles
Earth’s Magnetic Field - Wikipedia
Earth’s Magnetic Field Is 3.5 Billion Years Old
Intro to magnetic fields - What is the structure of the Earth’s magnetic field?
Magnetite - Wikipedia
Henges: Stonehenge, Woodhenge, Avebury & Stanton Drew (Video)
Moral judgments can be altered ... by magnets
Earth’s north magnetic pole racing towards Russia due to core flux
Nathan Stubblefield and Electromagnetism
Russians order Flight Changes, after Massive Magnetic Shift downs Airliners
Playing the Field: Geomagnetic Storms and the Stock Market
’Hidden Portal’ Concept Described: First Tunable Electromagnetic Gateway
Chris Dunn & Great Pyramid 3D Electromagnetic Power Plant Walkthrough (Video)
Oceans charge up new theory of magnetism
Mayan Calendar & Human DNA II - Prophesies & Sun Magnetic Reversals - part 1 (Video)
Sweet dreams are made of geomagnetic activity
Magnetic Portals Connect Sun and Earth
Phoenix Pole Shift


Latest News from our Front Page

DNA discovery unearths 'unknown chapter in human history' in Europe 15,000 years ago
2016-02-09 4:31
Scientists studying the DNA of ancient Europeans found evidence of a 'major population upheaval' at the end of the last Ice Age A major and unexplained population shift occurred in Europe around 15,000 years ago when local hunter-gatherers were almost completely replaced by a group from another area, scientists researching our ancestors' genetics have discovered. The findings were made after the ...
Hackers Leak Info on 9,372 DHS Employees
2016-02-08 22:30
Homeland Security claims there is no indication that any breach of sensitive or personally identifiable information occurred Hackers released the names, positions, phone numbers and email addresses of more than 20,000 alleged FBI employees Monday only hours after leaking similar data from more than 9,000 people at the DHS. The group claiming responsibility, known as “DotGovs,” first alerted Infowars to the alleged ...
Gyms, Wikipedia, & Anti-White Racism
2016-02-08 22:16
A media-generated “uproar” following the innocent renaming of a River Falls, Wisconsin, school gym, and the blatant manipulation of Wikipedia, have served as the latest examples of the ongoing anti-white racism which is becoming endemic in society at large. As reported in the River Falls Journal, the Meyer Middle School in River Falls, Wisconsin, needed a new fitness center. To this ...
Pegida's Multi - Culti (state) Agenda!
2016-02-08 4:49
This guy raises some very interesting points regarding the recent PEGIDA launch in the UK and around Europe. Make sure to check out the videos below. The focus on the criticism descends into a Nazi accusation contest. "No no THEY are the REAL Nazi's." Pegida UK is fronted by Tommy Robinson, Paul Weston and Anne Marie Waters. They held a demo in ...
Sweden plans to expel up to 80,000 asylum-seekers (that didn't seek asylum)
2016-02-08 3:58
Enrichment Sweden intends to expel up to 80,000 migrants who arrived in 2015 and whose application for asylum has been rejected, Interior Minister Anders Ygeman said Wednesday. Ed: Wait, so they are in the country despite being rejected asylum? How did that happen and who let them in then? "We are talking about 60,000 people but the number could climb to 80,000," the ...
More News »