The night shift has returned with plenty of core for the science team nearly 22 meters! Check them out in this photograph. The sediment cores are arranged in order of depth, with the uppermost/youngest sediment at the far right where Dr. Pedro Tapia is pointing. Notice the dramatic changes in color as we drill deeper into the lake. These transitions in color represent changes in the composition of the lake sediments. For instance, the light tan-brown sediment is mostly made of carbonate and contains bits of organic material, like grasses, gastropods, and bivalves. In contrast, the light gray sediment is made of fine, silty -glacial flour- transported to the site during colder glacial periods when glaciers were actively eroding the valleys in the eastern cordillera. Photo and post: Christine Chen