Foy Lake, Montana Oxygen Isotope Data covering the last 2,200 years Stevens, L.R.; Stone, J.R.; Fritz, S.C. Stevens, L.R. Stone, J.R. Fritz, S.C. earth science/paleoclimate/paleolimnology (delta 18O,calcium carbonate,null,per mil VPDB,null,paleolimnology,null,null,N,sediments <63um) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (Foy Lake, Montana>LATITUDE 48.166667>LONGITUDE -114.35) A 2200-yr long, high-resolution ( ~5 yr) record of drought variability in northwest Montana is inferred from diatoms and d18O values of bio- induced carbonate preserved in a varved lacustrine core from Foy Lake. A previously developed model of the diatom response to lake-level fluctuations is used to constrain estimates of paleolake levels derived from the diatom data. High-frequency (decadal) fluctuations in the de- trended d18O record mirror variations in wet/dry cycles inferred from Banff tree-rings, demonstrating the sensitivity of the oxygen-isotope values to changes in regional moisture balance. Low frequency (multi-centennial) isotopic changes may be associated with shifts in the seasonal distribution of precipitation. From 200 B.C. to A.D. 800, both diatom and isotope records indicate that climate was dry and lake level low, with poor diatom preservation and high organic carbon: nitrogen ratios. Subsequently, lake level rose slightly, although the climate was drier and more stable than modern conditions. At A.D. 1200, lake level increased to approximately 6 m below present elevation, after which the lake fluctuated between this elevation and full stage, with particularly cool and/or wetter conditions after 1700. The hydrologic balance of the lake shifted abruptly at 1894 because of the establishment of a lumber mill at the lake's outlet. Spectral analysis of the d18O data indicates that severe droughts occurred with multi-decadal (50 to 70 yr) frequency. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Stevens, L.R. Investigator : Stone, J.R. Investigator : Fritz, S.C. 2017-11-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23080 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Foy.Stevens.2006.lpd https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Foy.Stevens.2006.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Foy.Stevens.2006.lpd https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Foy.Stevens.2006.txt English https://www.ncdc.noaa.gov/paleo/study/23080 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Foy.Stevens.2006.lpd https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Foy.Stevens.2006.txt Stevens, Lora R., Jeffery R. Stone, Josh Campbell, and Sherilyn C. Fritz2006A 2200-yr record of hydrologic variability from Foy Lake, Montana, USA, inferred from diatom and geochemical dataQuaternary Research652264-27410.1016/j.yqres.2005.08.024 START YEAR: 3113 cal yr BP * END YEAR: -42 cal yr BP -114.35 48.166667 -114.35 48.166667