### Rock of Ages

Posted:

**Thu Apr 05, 2012 8:24 pm**Dear al(L)

New Scientist 7 April suggests "Ages of oldest rocks are off by millions of years"

'Two ofthe solar system's best time keepers have been caught misbehaving, suggesting the accepted ages for the oldest known rocks are wrong ..................

using radioactive samarium-146 .........converge' on a half life of 103 million years ,plus minus 5 million.........................' using a newer,more accurate technique, M Paul, Hebrew University in Jerusalemfound the figure is just 68 million ............................that means some Martian meteorites - formed 20 million to 80 m years earlier than thought......................

A second hiccup, concerns a pair of uranium isotopes,which decay into two lead isotopes...................................

Now Joe Hies of the British Geological survey & colleagues have made the widest ranging study of uranium isotope ratios yet .................................

That led them to ..................shifts the ages of the Earth's oldest rocks thought to be 4.4 billion years old are now younger by 700,000 years.

""If the Earth was only 18 years old, we would have to take 1 day off the life of its oldet materials...........

it might seem small but ........................If a mass extinction occurred just before a meteorite struck, that paints a very different picturethan if the meteorite hit first..............."

Best wishes from Cliff

New Scientist 7 April suggests "Ages of oldest rocks are off by millions of years"

'Two ofthe solar system's best time keepers have been caught misbehaving, suggesting the accepted ages for the oldest known rocks are wrong ..................

using radioactive samarium-146 .........converge' on a half life of 103 million years ,plus minus 5 million.........................' using a newer,more accurate technique, M Paul, Hebrew University in Jerusalemfound the figure is just 68 million ............................that means some Martian meteorites - formed 20 million to 80 m years earlier than thought......................

A second hiccup, concerns a pair of uranium isotopes,which decay into two lead isotopes...................................

Now Joe Hies of the British Geological survey & colleagues have made the widest ranging study of uranium isotope ratios yet .................................

That led them to ..................shifts the ages of the Earth's oldest rocks thought to be 4.4 billion years old are now younger by 700,000 years.

""If the Earth was only 18 years old, we would have to take 1 day off the life of its oldet materials...........

it might seem small but ........................If a mass extinction occurred just before a meteorite struck, that paints a very different picturethan if the meteorite hit first..............."

Best wishes from Cliff