I do the same thing in my work, just with the little shells of organisms that have lived all through the water column. Like a diary entry, these shells record the water conditions in which they lived, and by analyzing these shells we can reconstruct what the water looked like during their lives, many thousands of years ago!
While in Germany, I have started to work on mud from the Southern Ocean (see the map) that covers the last 40,000 years of Earth history. Every day, I get to take a trip to the Southern Ocean and a second journey back in time by using my little shells as tour guides, all without stepping outside my laboratory!
