Tuesday, 23 July 2013
Diamond is a Palaeontologists best friend....
I can already hear the gentle hum of nudged particles circumnavigating the vast Diamond storage ring at relativistic speeds....yes, once more the Manchester Palaeontology Research Group are headed to the UK Synchrotron facility. We have spent the last few weeks preparing our prehistoric samples for the ultimate examination, one that takes place at the atomic scale. We aim to tease dilute traces of past biochemistry from our fossils using the astoundingly bright monochromatic x-ray light that only an accelerator can generate.
This weekend we will be working in the realm of Extended X-ray Absorption Fine Structure spectroscopy (or EXAFS for short). EXAFS spectroscopy is sensitive to the electronic structure of the probed central absorber atom, and is especially able to accurately quantify distances from one shell of electrons to the next surrounding an atoms nucleus. This technique provides a great deal of information as to the atoms biological or geochemical context. In other words, was the atom emplaced within the organism while it was still alive, or did a geological process place a strategic atom to later bamboozle palaeontologists. This is of huge importance when trying to understand the chemical ghosts of extinct organisms, given each atom has its own diagnostic fingerprint....and its our task to run those prints!