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Update Date: 2008/09/27 04:09
[Compiled by Zheng Siyin / Comprehensive Report]
The ancient bedrock belt on the eastern coast of Hudson Bay in northern Quebec, Canada, may be the oldest known crust on Earth. A research report published in the British journal "Nature" on the 26th indicates that this rock dates back to 4.28 billion years ago, suggesting that land formed early in Earth's history, overturning the long-held theory among geologists that the young Earth was a sea of magma.
Earth formed 4.6 billion years ago. Geologist O'Neill from McGill University in Montreal, Canada, stated that this bedrock belt formed less than 300 million years after Earth's birth and is the oldest known rock, opening a door to further unravel the secrets of Earth's origins. Previously, the oldest rock discovered on Earth was in northwestern Canada, with a history of about 4.03 billion years, and geologists have also found zircon crystals dating back 4.36 billion years in a younger rock in western Australia.
O'Neill and colleagues from the University of Quebec determined the age by using two rare elements, neodymium and samarium, found in the rock. The chemical composition of the rock appears very similar to the characteristics of the seabed beneath continents, indicating that the processes of continental plate tectonics, reorganization, and movement may have begun very early in Earth's history.
At the very least, these 4.2-billion-year-old rocks will refute the past notion that the young Earth was a sea of magma, an idea that has gradually been abandoned by geologists as more data has emerged.
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080927/ 78/ 16nbq. html
Oldest Rock Found in Canada Rewrites Geological History
[Compiled by Zheng Siyin / Comprehensive Report]
The ancient bedrock belt on the eastern coast of Hudson Bay in northern Quebec, Canada, may be the oldest known crust on Earth. A research report published in the British journal "Nature" on the 26th indicates that this rock dates back to 4.28 billion years ago, suggesting that land formed early in Earth's history, overturning the long-held theory among geologists that the young Earth was a sea of magma.
Earth formed 4.6 billion years ago. Geologist O'Neill from McGill University in Montreal, Canada, stated that this bedrock belt formed less than 300 million years after Earth's birth and is the oldest known rock, opening a door to further unravel the secrets of Earth's origins. Previously, the oldest rock discovered on Earth was in northwestern Canada, with a history of about 4.03 billion years, and geologists have also found zircon crystals dating back 4.36 billion years in a younger rock in western Australia.
O'Neill and colleagues from the University of Quebec determined the age by using two rare elements, neodymium and samarium, found in the rock. The chemical composition of the rock appears very similar to the characteristics of the seabed beneath continents, indicating that the processes of continental plate tectonics, reorganization, and movement may have begun very early in Earth's history.
At the very least, these 4.2-billion-year-old rocks will refute the past notion that the young Earth was a sea of magma, an idea that has gradually been abandoned by geologists as more data has emerged.
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080927/ 78/ 16nbq. html