Friday, November 16, 2007

A busy week for the science team and 800 meters down!

The current depth of drilling is at more than 800 meters below the sea floor. The sedimentology team has logged and decribed more than 700 meters of core and we are starting to feel a bit worn down. We are getting beautiful rocks though, like the ones in the photos below. We still see diamictites but the last few days they alternate with mudstones that are laminated or layered. In the photo the layers are at an angle, tilting, which is a sign of disturbance of the original beds. Sediments are always laid down horizontally, so if we see these tilted layers, we know that something happened to the layers after deposition. Details like these are recorded by us, the sedimentologists, in the core descriptions. We also found very flat-laminated rocks. You can see us at work in the photo above (photo by Tracy Frank). These mudstones are important to the science team because they potentially indicate conditions away from an ice sheet, although some mudstones may accumulate very close to a glacier. We will find out by analyzing their composition and the microfossils they enclose. For example: if there was vegetation on land with formation of soils, we would find pollen of plants and clay particles indicative of chemical weathering in soils in the mudstones. The pollen and soil materials were washed into the ocean from land and the particles accumulated as mudstones. So: we can analyze the composition of the mudstones and reconstruct what the environment was like on land in the past.

Yesterday I took some time to take a walk around the peninsula. The weather was very calm and I enjoyed the view across the sound and the presence of Mount Erebus, the active volcano. I also encountered two skuas, who totally ignored me so I decided to take a picture of one of them.

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