History of travertine deposition in Yellowstone caldera and correlation with past climate conditions

History of travertine deposition in Yellowstone caldera and correlation with past climate conditions. a) The age of travertine samples (based on the U-²³⁰Th geochronometer) from Old Hillside Springs, Hillside Springs, North Hillside Springs, and Morning Glory in Upper Geyser Basin and from Firehole Lake in Lower Geyser Basin. Travertine deposits formed during or shortly after cool and wet climatic periods. The Pinedale Glaciation was the last time ice covered Yellowstone Plateau, the Younger Dryas Cold Event was a global cold period thought to be caused by disruptions in ocean circulation, and the Yellowstone Lake Cool Period has been identified by climate and ecology scientists investigating Yellowstone Lake sediment cores. The gray histogram on the right side of the plot indicates the relative amount of travertine deposition that occurred over time. b,c,d) Photographs of sectioned and polished travertine under short-wave ultraviolet light, which causes the travertine to fluoresce different colors based on the trace metals that are found in different layers. Green is associated with high uranium concentrations, and pink is from manganese. Scale bars indicate 1 cm (0.4 in). b) Hillside Springs c) near Morning Glory Pool d) Firehole Lake. Photographs taken under research permit YELL-2021/2022-SCI-8192.