Here we go, page-22

Hi rorter, yes have previously worked in the general area. Regarding suspect samples - well both batches can't be right so something's gone wrong somewhere as the company has stated. Yes have also dealt with a lab contaminated batch of calcrete samples - can waste a lot of time and money getting to the bottom of it.

Re calcrete - Yes the plant/tree connection seems to be the best explanation but not all "calcrete" is suitable as a sampling medium as it can form from a range of sources and its usability is highly dependent on the depth and type of cover.