Geology

Ireland

     The stamp was issued in 1995 to mark the centennial of the Geological Survey of Ireland. There is no official key to the map, but a comparison with a map of mineral deposits in Ireland from the Irish Association for Economic Geology suggests the following::
          Rust - Granite
          Yellow - Dalradian (Late Proterozoic/Cambrian)
          Light Blue, Grey-green, and Purple - Lower and Middle Carboniferous
          Orange - Devonian
          Red-violet, Olive - Upper Carboniferous & Younger

Mullfjället, Sweden

     The map is a geological map of the area around Åreskutan in the middle of Sweden. It is a mountanous region known for skiing and copper mining.