ABOVE: (left) Chris squirts acid on a core to test for calcium carbonate content. (right) A glacial deposit called a ‘diamictite.’ It’s a mixture of mud, sand, and gravel that was essentially bulldozed up by a glacier and eventually deposited at our drillsite in McMurdo Sound. The comings and goings of such deposits in the core provide clues about changes in the extent of glaciers (and, hence, climate change) through time.
Chris’ job down here is to describe the core itself, in terms of changes in sediment types, fossil content, etc., and to provide an interpretation of the environment in which the sediments were deposited. He works with a group of 5 others to do this each night.
Core is delivered from the drillsite by helicopter each night at around 10 PM. While I’m busy squeezing pore water from samples, Chris and the others are down the hall describing the core. Each morning, they provide a show-and-tell for the day-shift folks, who then work to determine the age of the sediments and to provide more detail about depositional environment.
