Paper No. 9
Presentation Time: 1:30 PM-5:30 PM
HOLOCENE OSL AGE ESTIMATES OF PARABOLIC DUNES ALONG THE WESTERN SHORE OF LAKE MICHIGAN, DOOR PENINSULA, WI, USA: INSIGHTS ON THE COASTAL DUNES GEOMORPHIC HISTORY
BEAL, Irina, Geology, Bates College, Lewiston, ME 04240, BURICH, Brooke, Geography and Geology, University of Wisconsin-Stevens Point, Stevens Point, WI 54481, FLINNER, Nick, Geography and Geology, University of Wisconsin-Platteville, Platteville, WI 53818, GRABOS, Nicole, Geosciences, Indiana University Northwest, Gary, IN 46408, GRAZIA, Eric, Geography, University of Wisconsin-Madison, Madison, WI 53706, HANSON, M.H., Geology, Whitman College, Walla Walla, WA 99362,
MESKEL, Bethany, Geography, Geology and the Environment, Slippery Rock University, Slippery Rock, PA 16057, WYCECH, Jody, Department of Chemistry, Grande Valley State University, Allendale, MI 49401, RAWLING III, J. Elmo, Geography/Geology, University of Wisconsin Platteville, 1 University Plaza, Platteville, WI 53818 and HANSON, Paul R., School of Natural Resources, University of Nebraska-Lincoln, 3310 Holdrege Street, Lincoln, NE 68583, bxm0052@sru.edu
A detailed study of the geomorphology and geochronology of dunes on the northwestern shore of Lake Michigan at Whitefish Dunes State Park, Door County, Wisconsin was conducted. Three-meter LiDAR, aerial photographs, and field observations reveal a series of parabolic dunes superimposed on an 800 m wide strand plain that separates Lake Michigan from Clark Lake. There are two distinct sets of dunes, larger dunes (18-24 m relief) adjacent to Lake Michigan and smaller dunes (3-7 m relief) farther inland. Closer to Clark Lake are a series of approximately 1 m tall beach ridges. The parabolic dunes show a paleowind direction of SSW. Percent coarse sand composition along transects between the modern beach and dunes distinguish between eolian sediment (~2.7%) and beach sediment (~18%). Particle-Size-Analysis (PSA) along with Ground Penetrating Radar (GPR) distinguished dune and beach strata.
Sixteen samples were collected for Optically Stimulated Luminescence (OSL) from paleo-beach sediment (n=2) and dune crests (n=14). These samples were processed using the single-aliquot regenerative method with 90-180 mm quartz grains. OSL ages are 4.6 ka for a beach ridge landward of the dunes and 4.4 ka for beach sand underlying the dunes. OSL ages of the dune crests ranged from 7.8 to 1.9 ka. Eight dune ages fell between 5.2 and 4.0 ka, which correlates with the Nippising Lake Level High (6.0-4.3 ka). The similarity between the dune and beach sediment ages suggests rapid dune formation and stabilization. Three dune ages between 2.6 ka and 1.9 ka suggest that some dune activation may have been associated with the Algoma Transgression (3.3-2.3 ka). This research was made possible by the Dune Undergraduate Geomorphology and Geochronology Project, a National Science Foundation Research Experience for Undergraduates.
![[Visit Client Website]](/img/gsa/banner.jpg)