31st July 2014 Sol 705

We have been analysing the Windjana drill tailings for over 2 months now and have just dumped the drill tailings.

The long and repeat analyses by SAM and CheMin allowed us to look at the effects of degassing of samples over time (e.g. the noble gas argon, used in K-Ar dating) and to get the best XRD analyses.  Exposing the drilled powder samples to the X-ray source over several occasions allows us to track any potential changes e.g. in hydration state of the tailings and to get better ‘counting statitics’ from which mineral abundances are determined.  For that we fit the position and shape of the peaks to standard spectra here on Earth using what is called the Rietveld Method.