Scientists discovered what seems to be the oldest known piece of the earth’s crust. The old rocks were found in northern Quebec, Canada, and the findings were published in Friday’s issue of the journal Science.

According to the measurements made by the scientists involved in this discovery, the rocks are 4.28 billion years old, which means that they were formed when our planet was under 300 million years old. Among other things, the discovery shows that the earth looked pretty much like today back then, said Richard W. Carlson of the Carnegie Institution of Washington.

The scientific community was intrigued by the findings. The rocks may be what’s left of the earth’s crust which formed on the planet's surface as it cooled after the birth of the solar system.

However, some scientists are still skeptical over the discovery.

“There is a certain amount of healthy skepticism that needs to play a role here,” said Stephen J. Mojzsis at the University of Colorado.

The place where scientists discovered the rocks is near Quebec. It’s actually a 4 square miles (10 square km) area of volcanic rock basalt. The age of the rocks was determined by using isotopic dating methods which enable scientists to analyze the elements samarium and neodymium.

The nature of the rocks can give clues about how the earth formed and at what temperatures.  
So far, the rocks found near Quebec are the oldest dated on earth. Scientists have found older bits of the earth - tiny and zircon crystals 4.36 billion years old. Scientists estimate the earth is more than 4.5 billion years old. No evidence of life was found in the rocks near Quebec. The oldest form of life on earth was probably bacteria.

"We know that probably the right environment was there for life to be on the Earth -- so liquid water and all it takes to have life. Now was there life? This is a big question mark," said Jonathan O'Neil of McGill University in Montreal.

The previous oldest dated rocks (4.03 billion years old) are in Canada's Northwest Territories.