This new age will contribute calibrating the geological time scale.This is a photograph of the geological section across the Matuyama-Brunhes boundary in Chiba Prefecture, Japan. (b) and (c) Detail of a volcanic ash layer (Byk-E) just below the MBB in the Chiba section.For example, they assume that rates of radioisotope decay, measured for less than a hundred years, have been the same for millions or billions of years into the past.
[The 4 biggest milestones in the history of life on Earth] They made their find in July 2012 while doing field research in Isua, a region of Greenland so remote that they had to travel there by helicopter.
The site is known for having some of the oldest rocks on Earth, in what is known as the Isua supracrustal belt.
They examined the outcropping and immediately saw something intriguing: conical structures, just one to four centimeters (less than two inches) high.
They look like fossilized microbial mats — basically, pillows of slime — known as stromatolites, which are formed today by bacterial communities living in shallow water. These look like stromatolites,' " Nutman told The Washington Post.
Scientists probing a newly exposed, formerly snow-covered outcropping in Greenland claim they have discovered the oldest fossils ever seen, the remnants of microbial mats that lived 3.7 billion years ago.