Marking time

One thing all geologists want to know is the age of the rock they are looking at and the most common way of doing that is by looking at the fossil assemblage in the sediments. When working with a thin core from the bottom of the ocean as we do here we are obviously not likely to find a fossil horse or a dinosaur but instead we rely on microfossils that represent the ancient plankton of the ocean. The smallest fossils we deal with are made of calcium carbonate and are called “nannofossils” that require the use of powerful microscopes in order to identify. On Expedition 355 this work is being done by Denise Kulhanek, who is also our staff scientist, and by Claire Routledge a New Zealander now studying for a Masters degree at Florida State University. In this photograph you see her taking a quick break from staring down the microscope where she is keeping us up-to-date with how old these sediments are, currently around 10 million years. It takes a good pair of eyes and a lot of coffee to focus on this type of thing for 12 hours a day.