Iron Sulphides and Surface Heating: Further Engineering Considerations for the Dublin Area

The problem created by the oxidation of pyrrhotite in a number of countries is reviewed and it is concluded that pyrrhotite is more common in Ireland than is generally appreciated. Research into the variable size/structure of pyrite/pyrrhotite framboids and the fractured nature of some of the microcrystals is presented. It is proposed that this may result from tectonic/fault movement. It is likely that the emanation of ground-sourced heat affects the rate of oxidation of iron sulphides and the consequential distress, which may therefore vary within an estate, even if the same aggregate is used beneath the houses.