Guld i Sverige - Från urtid till nutid
The Earth and everything else in the universe was created in the Big Bang around 14 billion years ago. A point with tremendous density and mass began to expand and more and more atoms began to form. From the first and lightest like hydrogen and helium to heavier atoms such as iron and eventually gold. The formation of the Earth occurred about 4.6 billion years ago and so the first gold atoms were concentrated only here. It is however believed that much later in Earth's history an extra supply of gold occurred thanks to massive meteorite bombardments. Processes in the Earth's interior has since led to the formation of the continents that move around, which has created hydrothermal processes. These are important since gold is a precious metal and as such it binds reluctantly to other elements in the periodic table. Instead, it occurs in either sulfide or chloride complexes. The complexes makes gold soluble in fluids of different magmas that form due to tectonic and hydrothermal processes. Depending on the process and environment, different types of ore bodies containing gold that form. From porphyry-deposits formed at high depths to VMS-deposits may form on the sea floor or other marine environments. Some of these ores-types can be found in Sweden and are mined at several sites, including the Björkdal-mine and the Aitik-mine.