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Palomar

Member

From: USA

Registered: 2002-05-30

Posts: 9,734

Re: Zircons

Read me

*They're claiming 99% accuracy.  And now my hubby's calling me to get off the computer and watch TV with him.    Is a brief article; enjoy. 

As the Earth's tectonic plates separate over time, new crust is created at mid-ocean ridges, says John. Minerals in the rocks that make up the crust are magnetized in the direction of the Earth's magnetic field as they cool and freeze. Because the field reverses polarity over time, the rocks record the polarity, creating alternating stripes on either side of a mid-ocean ridge.

Hmmmm...that's new to me.  Cool.

"Our finding that these zircons are older than they should be relative to their magnetic age alters what we've thought about oceanic crust, he says. "The ability to date zircons in ocean crust offers another and better way to determine how ocean crust is formed."

About 25 percent of the samples were 2.5 million years older than predicted by conventional models of crust generation at mid-ocean ridges.

--Cindy

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We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)