1 Illinois State Geological Survey, University of Illinois at Urbana-Champaign, 615 East Peabody Drive, Champaign, Illinois, USA. 2 Département des sciences de la Terre et de l’Atmosphère, Université du Québec à Montréal, Montréal, Québec, Canada. 3 Prairie Research Institute, University of Illinois at Urbana-Champaign, 615 East Peabody Drive, Champaign, Illinois, USA. * Corresponding author: c...