Scientist Brian Buma looks for a suitable site for taking core samples during a research trip to Cape Horn Island (Isla Hornos). Buma, the expedition leader, explained that ''The purpose of coring the ground was to see what vegetation on the island looked like in the past. The places where we took the cores were little depressions that would collect things washing off the hill above, and in principle the lower you go, the further back in time you look because new stuff washes in on the old stuff. So, we want to see if we can pinpoint the arrival of trees on the island by looking for either macrofossils like leaves or for pollen. Ideally we'll find a level where there is no tree pollen - below that is the time prior to trees. We can then date any carbon material that we can find (assuming we can) and get an approximate timeline for when trees arrived. It is of course also possible that trees were there when that moor started forming (or it's been washed out) and so it isn't old enough - just don't know yet. We found three good spots, deep (and so presumably the bottom is old). We took cores down to 2.43m in one location. Each core is about 5 cm across.''