Oldest traces of life on Earth locked inside Greenlandic gems – University of Copenhagen

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11 August 2017

Oldest traces of life on Earth locked inside Greenlandic gems

ESSENTIAL ELEMENTS

Scientists have found traces of the most ancient life inside a 3,7 billion years old gem using a new method through which the scientists may accurately measure small quantities of carbon and other elements essential for living organisms in old material from living organisms. The material is found within garnets from the Isua Supracrustal Belt of Western Greenland. The research is being published in an article in the scientific journal Nature. The team consists of, among others, Tue Hassenkan from Nano-Science Center, University of Copenhagen and Professor Minik Rosing of the Natural History Museum of Denmark, University of Copenhagen.

Using a new method, scientists have found traces of carbon, oxygen, nitrogen and phosphorus capsuled inside a microscopic garnet crystal. These elements, together with hydrogen, are the basic, essential building blocks of life, which is why it is exactly these elements that scientists searching for the oldest life are looking for.
The fact that the garnets do not contain hydrogen is in fact supportive of the hypothesis that the material represents old life forms. The hydrogen molecule is so small – says Minik Rosing of the Natural History Museum of Denmark – that it may readily escape the gem, even if the gem is still intact. Left in the gem is nitrogen, oxygen, phosphorus, and carbon. The fact that hydrogen is no longer present in the gem supports the idea that the rock is very old and that it has not been contaminated later on.

Garnet crystal cut by a band of black organic material. The organics inside the garnet has been locked and isolated. Photo: Minik Rosing.

Garnet crystal (white) cut by a band of black organic material. The organics inside the garnet has been locked and isolated. Photo: Minik Rosing.

Even though the organics inside the gem is not as easily observed as a mosquito inside a lump of amber is, evidence of life, probably bacterial life, is still present inside the gem.
Using the new method, the team can analyze the carbon while it is still inside the gem. And it is evident that the nitrogen, oxygen, and phosphorus is still bound to the carbon in a manner that would be expected of organic molecules having been pressure cooked inside the garnet for millions of years, says Tue Hassenkam of Nano-science Center.

The new method combines two techniques which enables the study of materials on a near-molecular scale. One technique used in the new method is the mechanical “atomic force” microscope, in which a very thin needle is used to profile the surface of the material. The other technique is based on infrared spectroscopy. Combining the two techniques allows the scientists to observe how the surface reacts to the infrared light, and thus determine the type of chemical bond in the material.

The article in Nature may be read here.