 **The main reason for the occurrence of the slide in Nicolet, Quebec is the type of soil in the area of which the slide occurred.Beneath the 8-foot thick stratified fine sand layer, was a thick stratified gray clay that extended to the depth of 35 feet and below that, was a darker clay with black mottling with a thickness of 100 feet.The clay is marine/Leda clay that is "extra sensitive" or "quick".