On that fateful day when the meteorite struck, the composition of the earth literally changed. We accepted an extraterrestrial package that, among other things, kicked up quite a bit of dust. When the dust settled, it contained material from the meteorite which became trapped as more sediment was deposited on top over the millions of years that lead us to the present day. This means that it is easy to identify layers of rock that were deposited at the time of the great extinction. These layers contain a very distinctive iridium-rich clay. A site containing this clay was recently discovered in North Dakota and a team of researchers at the University of Manchester have collected samples from the site to study at Diamond.
Prof Andrew Harrison, CEO at Diamond Light Source explains:
The samples from North Dakota were taken to I18, the microfocus beamline at Diamond. This beamline uniquely allows users to map the chemical elements of a sample in 3D space. By placing a fossil in the X-ray beam and collecting masses of data, it is possible to see what elements were present in the fossil and where. This helps researchers to understand the biological and chemical processes that were occurring 66 million years ago.
It is also possible to focus in on individual elements at I18. It is well known that the meteorite impact released a lot of sulphur, but in what form is not completely clear. By studying this and understanding what forms of sulphur were present, the research team can understand the kinds of environmental changes that happened as a result of the impact. This will help us understand what the days and months following the impact were like on earth, perhaps giving us more insight into how the mass extinction progressed.
The resolution provided by I18 will allow the researchers to closely examine the chemical composition throughout the iridium-rich clay and understand how the composition changed over time. It is hoped that this will help to paint an accurate picture of the dynamics and the timings of the events that followed the meteorite impact which until now, have remained illusive.
The chemicals in these samples can tell us a lot about the earth at the time of the meteorite impact. The types of elements present, their oxidation sate and where they are located can give us clues as to the invisible chemistry that was going on at the time when the dinosaurs became extinct. Elements that are associated with living things leave their imprint on the fossil record and it is up to scientist to develop the tools that can measure them.
Prof Phil Manning, Lead Investigator from Manchester University adds:
Thanks to Diamond and other synchrotrons around the world, fossils and other ancient objects are back in the research spotlight. Something that we once thought exhausted in research terms has now returned from the dead and taken on a whole new life. As technology advances we can do more and more with fossil specimens. It doesn’t stop here – there are always more questions we can ask.
As you can imagine, the technology required to carry out these experiments is nothing short of state-of-the-art. Everything from the beamline, the sample preparation and the data analysis have been designed to get new information from these ancient rocks. To get better resolution and deeper knowledge, technology has to be pushed to the limit. This has a huge beneficial knock-on effect to other areas of science. If you can do these powerful imaging techniques on the impossible fossils, what would you see if you used them in medicine or agriculture? Studying the events of our prehistoric past can help shape our high-tech future.
Find out about other research undertaken by Prof Manning at Diamond here:
Diamond Light Source is the UK's national synchrotron science facility, located at the Harwell Science and Innovation Campus in Oxfordshire.
Copyright © 2022 Diamond Light Source
Diamond Light Source Ltd
Harwell Science & Innovation Campus
Diamond Light Source® and the Diamond logo are registered trademarks of Diamond Light Source Ltd
Registered in England and Wales at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom. Company number: 4375679. VAT number: 287 461 957. Economic Operators Registration and Identification (EORI) number: GB287461957003.