Splitting core

Hi crew: After the cores have passed along the MST track, Natural Gamma analyzer, and Thermal Conductivity, then the sections are split down the middle. One half is called the Archive Half, the other is the Working Half.

Core description is done on the Archive Half, while sampling takes place on the Working Half. We knew exactly what to expect at this site because a number of holes had been cored at this site, including the re-entry Hole 807C, during ODP Leg 130. The sediments consist of calcareous ooze. They are ~99.5% biogenic in origin; mostly the carbonate hard parts of microscopic plankton. I’ll tell you more about these organisms and how we analyze the sediments tomorrow.

Today’s picture shows the split sections (Archive Half) before they go to the image scanner (high resolution color scan of each core section). Gary is cleaning up the black tray after Section 1 was passed to Kristen who is running the image scanner (some of the cores in the upper part of a hole are a bit soupy because they haven’t yet experienced much compaction from the weight of overlying sediment, and therefore the water content is high). The split cores then go two other tracks to collect color reflectance and magnetic susceptibility, as well as physical properties such as density, vane shear strength, and p-wave velocity (some of the same types of measurements collected on the MST). To the left of Gary, Zenon is working with the core description software, while Heather and Roy on the right are analyzing samples for their physical properties.

Tomorrow: smear slides and microfossils (or, why you shouldn’t swallow sea water)

Mark L.