Found, Earth's Oldest Rock

QUEBEC, Friday - Scientists have discovered rocks that until recently believed to be the oldest rocks on Earth. Reached the age of 4.28 billion years old makes the stone more than 250 million years old rocks are found earlier.
According to scientific calculations, the Earth formed about 4.6 billion years ago from a disk of dust and gas surrounding the sun. But the remnants of crust from Earth that are hard to find because most of the material is recycled by the Earth due to the movement of tectonic plates that constantly change the Earth's surface.

In 2001, geologists found stone slab known as the Nuvvuagittuq greenstone belt in the east coast of Hudson Bay in northern Quebec. Suspecting that the rocks there may have originated from the earliest periods of Earth's history, geologists took samples to determine their age. They measured tiny variations in isotope (an element that have different numbers of neutrons) of the rare earth elements neodymium and samarium in the rocks and determined that the rocks were from 3.8 to 4.28 billion years old.
Age of the oldest, dating from the rock called "faux amphibolite", believed to be ancient volcanic deposits. This stone is considered the oldest rock beat before, with 4.03 billion years old and comes from a formation called the Acasta Gneiss, Canada's Northwest Territories.
The only material older than the beginning of the Nuvvuagittuq rocks are zircon from isolated mineral grains that are resistant to weathering and geologic processes. The oldest zircon grains from Western Australia about 4.36 billion years old.
Nuvvuagittuq stones are the oldest rocks found so far, said geologist Richard Carlson of the Carnegie Institution, who analyzed the rocks with Jonathan O'Neil, a doctoral student at McGill University in Montreal. Their research is published in the journal Science, published 25 September this.