Monday, February 22, 2010

Last bit of core through the lab?

Today was like many days on the cruise. Core was coming up and we were processing it through the lab. In the afternoon we stopped drilling and the hole was prepared for down-hole logging. More on that tomorrow. This may have been the last bit of core that we describe on our shift, so it is a good time to explain what goes on with these cores before we get them on the table. Here you can see Erik and John splitting a core for us. The core is hard, like rock, so they use a rock saw to cut it into two equal halves. One half is the Archive half: we get to describe that one and it is kept in pristine condition as much as possible. The other half is the Working half: that half gets sampled, so small pieces are cut out for laboratory analyses. After the split, we describe the features visible on the cut face of the Archive half. Today most of the rocks were laminated and some had nice microfaults (see photo). After core description the cores are photographed using a line-scan imager and fed through a logging track for measurements of color reflectance and magnetic susceptibility. After we have finished the measurements the section halves are wrapped in cling wrap and then fed into a D-tube for storage. Here you can see the D-tubes: those with the red caps are for Archive halves and those with the black caps for the Working halves.

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