Holocene lake-level changes in Celestine Lake,Canadian Rocky Mountains,identified using stable isotopes,geochemistry,and mineralogy

A multiproxy lake-level reconstruction from Celestine Lake, located in Jasper National Park, Alberta, Canada, provides quantifiable evidence for Holocene precipitation-evaporation balance. Celestine Lake produces authigenic carbonate in its shallow waters while preserving organic sediments in the deeper basin. Sedimentary analysis of three cores collected from Celestine Lake along a shallow- to deep-water transect, analysis of modern lake water geochemistry, and surface sediment characteristics provide a model for interpreting downcore changes in carbonate and organic matter content in the context of prolonged shifts in water level. The modern thermocline at 420–550 cm below water level matches the transition from shallow-water carbonates to deep-water organic sediment. Shallow-water carbonates are almost absent in the mid-depth core from 7–2 ka BP, suggesting a 1–2 m higher lake level during this period than from 11–7 ka BP and 2 ka BP-present when carbonate sediments dominate. Concurrent shifts in carbonate mineralogy and a ~5 ‰ increase in δ¹⁸O_CaCO3 indicate the erosion of detrital dolomite into the lake driven by the wetter conditions. Comparison to ~50 lake records across the North American Rocky Mountain region suggests that the middle Holocene wetness may have resulted from a northward shift in the westerly jet stream that increased the seasonality of precipitation and left the northern United States dry. The Celestine Lake dataset combines sedimentological analysis, stable isotopes, water geochemistry, and mineralogy to produce a record of significant and sustained lake level increases from 7–2 ka BP in the Canadian Rockies in response to large scale hydroclimate shifts.