Foundation options for building on marble ledge

[Toxotes]

I would like to get input as to what foundation options I have in building on top of fractured marble here in Vermont. The marble is at the surface in most areas with small pockets of soil no deeper than six inches. The marble joints create sections of rock that vary from approximately two to 18". Surprisingly, trees grow on this mountainside location, slowly forcing their roots between the fractures and causing further expansion in the summer with freezing runoff taking over the mechanics of this in winter. I plan on building a 22'x30' single story cabin on one relatively flat area. I had initially hope to pour a slab on grade, but I am concerned that I would have to get to solid rock to avoid water seeping underneath and freezing. Does anyone have any viable suggestions for building any type of foundation on this type of location?

 

[oldestguy]

Unless the joints are filled with significant thickness of frost susceptible silty soil, freezing of any water there will not cause heave of significance. What do things look like in exposed areas? Do you see heaving at the jints in winter?

I'd consider placing the slab on a closed cell sheet of the pink stuff (insulation), to make conditions inside more comfortable. Of course that may permit more freezing near the edges beneath, but probably not of concern.