Mono Lake: A Study in Sediments

Image: Mark Garcia

The 2022 photo calendar produced by the Division of Geological and Planetary Sciences (GPS) features winning photographs from a division-wide photo contest. This selection, Mono Lake Sediments From the Wilson Creek Formation, California, shows sediment deposits in the lake. The description states: “During glacial times, when Sierra Nevada glaciers extended to their maximum glacial positions, and the lake was greatly elevated, icebergs floated in Lake Russell and deposited drop stones in the Wilson Creek Formation.”

GPS research technician Mark Garcia captured this photo on June 20, 2021, while assisting with the International Geobiology training course, a five-week intensive summer program for PhD students and postdocs. At over 1 million years old, Mono Lake is one of the oldest in North America. Salts and minerals have washed into the lake, which has no outlet, from Eastern Sierra streams over time. The interaction of freshwater springs and alkaline lake water led to the formation of “tufa towers,” calciumcarbonate spires and knobs notable for their unusual shapes and abundance. These towers have aided science’s understanding of the climate history of this region. “We arrived about two hours before the group of geobiology students,” Garcia says of the day he took the photo. “Out of 12 photos I took, this one was my favorite.”