HOME >> BIOLOGY >> NEWS
3.2 billion-year-old surprise: Earth had strong magnetic field

ot be good enough. The technique was developed more than four decades ago, and has changed little. With the old method, an igneous rock about an inch across is heated and cooled in a chamber that is shielded from magnetic interference. The magnetism is essentially drained from the particles in the rock and then its refilled while scientists measure how much the particles can hold.

Tarduno, however, isolates choice, individual crystals from a rock, heats them with a laser, and measures their magnetic intensity with a super-sensitive detector called a SQUIDa Superconducting Quantum Interface Device normally used in computing chip design because its extremely sensitive to the tiniest magnetic fields.

Certain rocks contain tiny crystals like feldspar and quartznano-meter sized magnetic inclusions that lock in a record of the Earths magnetic field as they cool from molten magma to hard rock. Simply finding rocks of this age is difficult enough, but these rocks have also witnessed billions of years of geological activity that could have reheated them and possibly changed their initial magnetic record. To reduce the chance of this contamination, Tarduno picked out the best preserved grains of feldspar and quartz out of 3.2 billion-year-old granite outcroppings in South Africa. Feldspar and quartz are good preservers of the paleomagnetic record because their minute magnetic inclusions essentially take a snapshot of the field as they cool from a molten state. Tarduno wanted to measure the smallest magnetic inclusions because larger magnetic crystals can lose their original magnetic signature at much lower temperatures, meaning they are more likely to suffer magnetic contamination from later warming geological events.

Once he isolated the ideal crystals, Tarduno employed a carbon dioxide laser to heat individual crystals much more quickly than older methods, further lessening the chance of contamination. With the Universitys ultra-sensitive SQUID he could me
'"/>

Contact: Jonathan Sherwood
jonathan.sherwood@rochester.edu
585-273-4726
University of Rochester
4-Apr-2007


Page: 1 2 3

Related biology news :

1. What we can learn from the biggest extinction in the history of Earth
2. Chickens also orient themselves by the Earths magnetic field
3. Scientists ponder plant life on extrasolar Earthlike planets
4. NASA-funded robotic sub makes final dive to reach bottom of Earths deepest sinkhole
5. ESA presents the sharpest ever satellite map of Earth
6. Prototype space probe prepares to explore Earths deepest sinkhole
7. Worlds oldest rocks show how Earth may have dodged frozen fate of Mars
8. Climate change only one symptom of a stressed planet Earth
9. Researchers identify a heartbeat in Earths climate
10. Symposium Changes on Earth honors Yale Geologist Robert Berner
11. The Milky Way shaped life on Earth

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: billion year old surprise Earth had strong magnetic field

(Date:12/17/2014)... , Dec. 15, 2014 The Defense ... it easier to detect and prevent counterfeit microcircuits ... Today the agency started performing an in-house microcircuit ... validate the authenticity of purchased microcircuits while increasing ... quality control measures will be conducted at DLA,s ...
(Date:12/17/2014)... , Dec. 16, 2014  Automation is fundamentally ... more evident than at international borders. Over the ... scanners have allowed veteran travelers to self process ... Control (APC) Kiosks at an increasing number of ... According to Maxine Most ...
(Date:12/11/2014)... , Dec. 10, 2014  That blood pressure plays a ... while. Hypertension – the medical term for high blood pressure ... 1800s, and the inflatable cuff that,s used in measuring blood ... mean there,s nothing new about hypertension, its triggers and its ... about the condition and the best ways to treat it. ...
Breaking Biology News(10 mins):Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 2Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 3Automated Border Control (ABC) Transforms the Global Travel Experience With More Than 2500 ABC eGates and APC Kiosks Deployed In Airports, Seaports, and Land Borders Worldwide 2Research points to need for new approaches to treatment of high blood pressure 2Research points to need for new approaches to treatment of high blood pressure 3Research points to need for new approaches to treatment of high blood pressure 4
(Date:12/22/2014)... Illinois (PRWEB) December 22, 2014 ITRA ... tenants and occupiers of commercial real estate, has further ... new offices in Perth and Brisbane, Western Australia, reports ... of directors. , ITRA Global / ACORPP (Australian ... totally independent consultancy company providing property services to a ...
(Date:12/19/2014)... BioPlus Specialty Pharmacy (BioPlus), one of the ... Maroulis, Pharm.D. to the newly created position of Vice ... position, Dr. Maroulis will continue to manage the entire ... multi-site pharmacies as the company expands. Dr. Maroulis has ... he has served in many different capacities in the ...
(Date:12/19/2014)... BURLINGTON, Mass. , Dec. 19, 2014 ... biomaterial market will grow at a 12 percent compound ... a result of the aging population and the increasing ... Latin America will also spur demand ... results of dental implant and periodontal treatments. ...
(Date:12/19/2014)... 2014 LayerBio is an MIT spin-off ... care. The National Eye Institute (NEI) at the National ... I SBIR grant to develop a drug-eluting intraocular lens ... common cause of vision loss in people over age ... to Dr. Ken Mandell, LayerBio’s Founder and CEO, "There ...
Breaking Biology Technology:ITRA Global Continues International Expansion in Perth and Brisbane, Australia 2BioPlus Specialty Pharmacy Promotes Dr. Nick Maroulis to Vice President of Specialty Pharmacy Services 2Latin American Dental Biomaterial Market Will Expand at a 12 Percent Annual Growth Rate Through 2023 2Latin American Dental Biomaterial Market Will Expand at a 12 Percent Annual Growth Rate Through 2023 3LayerBio Awarded NIH Grant to Develop a Drug Delivery Device for Cataract Surgery 2
Cached News: