Growth and Migration of Parabolic Dunes Along the Southeastern Coast of Lake Michigan

• Published in: Journal of coastal research 2006-12, p.209-214
• Main Authors: Hansen, E.C., Arbogast, A.F., van Dijk, D., Yurk, B.
• Format: Article
• Language: English
• Subjects: Aeolian dunes; Dune soils; Dunes; Entisols; Forest soils; Inceptisols; Lakeshores; Peat soils; Sand; Sedimentary soils
• ISSN: 0749-0208; 1551-5036

Our goal was to uncover the geomorphic history of large parabolic dunes along the southeastern coast of Lake Michigan. We mapped dune paleosols, obtained radiocarbon and OSL dates, and measured contemporary wind patterns, sand transport and sand deposition with arrays of anemometers, wind vanes, sand traps and pins. Dune paleosols were divided into 4 units. The Basal Soil was buried during the Nipissing I transgression. Older members of the Lower Entisol Series were buried by a pulse of dune growth corresponding with the rise to and fall from Nipissing II high lake levels. Younger members of the Lower Entisol Series were buried during the inland migration of parabolic dunes that ended with a period of stability marked by an Inceptisol (The Holland Geosol). The Inceptisol was buried during a period of remobilization beginning before the arrival of European settlers and continuing today. Measurements on a typical, large parabolic dune showed that sand was deposited on upper and mid lee slopes during the fall and winter. Over steepened slopes were maintained through the winter by ice between sand grains. Slopes collapsed during the spring thaw and sand arrived at the base of the dune through mass wasting. Roughly 50% of deposition on the lee slope was associated with the two highest energy wind events. Very little deposition occurred in late spring and summer. Deposition along the lee slope reaches a maximum along the axis and falls off rapidly towards the limbs reflecting the topographic steering of winds within the trough.