Processing the cores

Transcript

Professor Dave Prior

There’s a certain amount of processing that has to be done on a particular bit of drill core before you move onto the next one. One has to process that core very carefully to make sure it’s scientifically useful. And the key things are what their relationship is to where we got them from, so we need to know how deep they’ve come from and we have to make sure that information is tagged correctly to the core. And when the core comes out of the ground, if you can imagine the core like that, it has a top end and a bottom end, and we have to make sure we know which is the top end and the bottom end, so which way was up. We would like to know which way was north in the core as well. That’s actually a lot harder because the process of drilling is a rotary drilling process, so the core gets spun. Quite often a core in reality is not a 3-metre tube of rock but it’s a small bit of rock and a pile of rubble. So someone has to reconstruct, well, where does the bit of rock come from and where does the rubble come from? And sometimes there isn’t an easy answer to that.

Acknowledgements Professor David Prior, Department of Geology, University of Otago. Stills of drilling rig and the Deep Fault Drilling Project site, courtesy of The Deep Fault Drilling Project – a multinational collaboration lead by GNS Science, the University of Otago and Victoria University of Wellington with researchers from the University of Auckland, the University of Canterbury, Liverpool University and the University of Bremen in Germany. Scientists from the United States and Canada are also participating.