AbstractThe Marine Ice Transgression Hypothesis (MITH) was proposed by Denton and Hughes (1981) to supplement the highland origin, windward growth (Flint, 1943) and the instantaneous glacierization (Ives. 1957) hypotheses for initiating glaciation during an ice age. The sequence of transitions from sea ice to fast ice to ice shelves to marine ice domes to an ice sheet is examined more closely, with special attention to how marine ice transgression may have produced the Laurentide Ice Sheet.