DISPLACEMENT OF SALT BY THE LAURENTIDE ICE-SHEET

In central New York, deformation of salt of the Salina Formation by the Laurentide Ice Sheet is shown by a thinning of the salt stratum in and near the outcrop zone where it was overridden by the ice sheet and by a thickening down-dip near the glacial limit. Less definitive suggestions of deformation by glacial overriding of the Salina outcrop zone in northeastern Ohio are seen in salt-cored anticlines in the vicinity of the glacial limit. In the lower peninsula of Michigan, isopachs of salt curve around Saginaw Bay, which suggests that the salt was displaced southwestward, away from the bay, by pressure of the Saginaw lobe of the ice sheet. All but one of the major Paleozoic salt deposits of North America lie in a zone that girdles two-thirds of the Canadian Shield from where glacial erosion removed all but occasional outliers of Phanerozoic strata. © 1992.