Three-dimensional diagram of mudboils and permafrost table

Location: Typical of till or marine mud-covered surfaces in Kivalliq, Nunavut, Canada

This figure, based on an original sketch by R. G. Skinner, who relied on data I supplied from excavations in the Kaminak Lake area, shows the typical configurations of the permafrost surface beneath a mudboil-covered active layer at maximum summer thaw. This figure originally appeared in Shilts, 1978; fig. 2, p. 1058. Image 0227 is a trench excavated to permafrost across mudboils developed in marine silty clay near Kaminak Lake; the measurements and observations from this trench and from excavating thousands of mudboils (for geochemical sampling) were used to construct the model. Components of excavated and unexcavated mudboils described elsewhere in this image set will be referred to this model; note particularly the relationships of the "carapace" and the diapiric silty sediment that pierces it during the thaw season. See detailed discussion for image 0240.

Updated 05/06/2010 AW