NOAA/WDS Paleoclimatology - Squanga Lake, Yukon Territory Holocene Stable Isotope and LOI Data

Sub-centennial oxygen (d18O) isotopes of ostracod and authigenic calcite from Squanga Lake provides evidence of hydroclimatic extremes and a series of post-glacial climate system reorganizations for the interior region of northwest Canada. Authigenic calcite d18O values range from -16 per mil to -21 per mil and are presently similar to modern lake water and annual precipitation values. Ostracod d18O record near identical trends with calcite, offset by +1.7 +- 0.6 per mil. At 11 ka BP (kaBP = thousands of years before 1950), higher d18O values reflect decreased precipitation-evaporation (P-E) balance from residual ice sheet influences on moisture availability. A trend to lower d18O values until ~8 ka BP reflects a shift to wetter conditions, and reorganization of atmospheric circulation. The last millennium and modern era are relatively dry, though not as dry as the early Holocene extreme. North Pacific climate dynamics remained an important driver of P-E balance in northwest Canada throughout the Holocene.