加拿大发现地球上最古老岩石

发布时间：2009-05-24

The oldest rocks on Earth have been discovered in Canada, offering scientists a glimpse at the origins of the planet, announced scientists in a study to be published Friday.

The rocks, found in a belt of ancient bedrock in Quebec, are estimated to be 4.28 billion years old.

The find pushes back the age of the most ancient discovered remnants of the Earth's crust by 300 million years.

"Our discovery opens the door to further unlock the secrets of the Earth's beginnings," said Jonathan O'Neil, lead author of the study and a geologist at McGill University in Montreal, who collected and analyzed the rocks.
"Geologists now have a new playground to explore how and when life began, what the atmosphere may have looked like, and when the first continent formed," said O'Neil.

The rocks also suggest that continents formed very early in the Earth's history, said Richard Carlson at the Carnegie Institution in Washington, co-author of the study, to be published in the September 26 edition of the journal Science.

Estimates of the rocks' age were made using isotopic dating, a technique which can only be used to date rocks roughly 4.1 billion years old or older.

This is the first time the technique has been used to date terrestrial rocks, because nothing else this old has ever been discovered on Earth.

The specimens were found in an area known as the Nuvvuagittuq greenstone belt, along the eastern shore of Hudson Bay in northern Quebec, a region recognized in 2001 as being a potential site for finding ancient rocks.
此文章由琥儿提供，佳禾外语进行整理。　

大连佳禾外语培训学校近期开班
课程名称 (点击查看更多班型)	试听	开课时间	班型	优惠价(元)	在线报名
N4级-N1级保过班		03-13	周末半日
N2级考前强化冲刺高分班		03-28	周六全天	960
N1级高分秘笈强化冲刺班		03-28	周日全天	1080