Sentences with phrase «zircons crystallize»

«Zircons crystallize out of molten rocks with special compositions, and their appearance signifies a profound change from silica - poor to silica - rich volcanism.

Those zircons crystallized about 234 million years ago, the team's analyses suggest.

Sometime after the zircons crystallized, possibly millions of years later, these bits of mineral eroded out of their parent rock and ultimately ended up being washed or blown into what is now central Colorado.

Not exact matches

A research team led by John Tarduno of the University of Rochester in New York went to Australia's Jack Hills and collected ancient samples of rock containing the crystallized mineral zircon.

Then they used uranium / lead dating to determine the age of each zircon (the time when its parent rock crystallized).

The new study confirms that zircon crystals from Western Australia's Jack Hills region crystallized 4.4 billion years ago, building on earlier studies that used lead isotopes to date the Australian zircons and identify them as the oldest bits of the Earth's crust.

Although the earth was extremely hot 4.0 — 4.4 billion years ago, some regions must have been cool enough to crystallize zircons.