Ørkendalen, Kangerlussuaq, Greenland Holocene Moraine 10Be Ages Levy, L.B.; Kelly, M.A.; Howley, J.A.; Virginia, R.A. Levy, L.B. Kelly, M.A. Howley, J.A. Virginia, R.A. earth science/paleoclimate/others (Ørkendalen Moraines>LATITUDE 67.145>LONGITUDE -50.16) Although Greenland ice core records register relatively stable Holocene climate conditions, the lower elevation margins of the Greenland Ice Sheet (GrIS) experienced significant Holocene fluctuations. These fluctuations include ice sheet recession during the Holocene Thermal Maximum (9-5 ka) and advance during the Little Ice Age (LIA; ~A.D. 1350-1880). Determining the extent and timing of these fluctuations is important for understanding the response of the GrIS to interglacial climate conditions both warmer and colder than at present and for developing accurate ice sheet models. Sets of moraines marking past extents of the southwestern GrIS margin occur in the Kangerlussuaq region. We focus on the Ørkendalen moraines, a prominent moraine set located within 2 km of the modern ice margin and just outboard of the LIA moraines. We present the first 10Be ages of the Ørkendalen moraines indicating they were deposited at 6.8 ± 0.3 ka. The geomorphic relationship between the Ørkendalen and LIA moraines indicates that the ice sheet margin was inboard of its Ørkendalen extent between ~6.8 ka and the culmination of the LIA. The age of the Ørkendalen moraines provides an important constraint on the extent of the southwestern GrIS during the middle Holocene. STUDY NOTES: 10Be ages on boulders on moraines, Ørkendalen, Kangerlussuaq, Greenland NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Levy, L.B. Investigator : Kelly, M.A. Investigator : Howley, J.A. Investigator : Virginia, R.A. 2013-12-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/15814 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/levy2012/orkendalen2012ages.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/levy2012/orkendalen2012ages.txt English https://www.ncdc.noaa.gov/paleo/study/15814 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/levy2012/orkendalen2012ages.txt Laura B. Levy, Meredith A. Kelly, Jennifer A. Howley, Ross A. Virginia2012Age of the Ørkendalen moraines, Kangerlussuaq, Greenland: constraints on the extent of the southwestern margin of the Greenland Ice Sheet during the HoloceneQuaternary Science Reviews521-510.1016/j.quascirev.2012.07.021http://www.sciencedirect.com/science/article/pii/S0277379112002880 START YEAR: 7390 cal yr BP * END YEAR: 6290 cal yr BP -50.16 67.145 -50.16 67.145