Banded Iron Formation (BIF)Banded iron formation is iron rich chert (cryptocrystalline silica (SiO2). The banded colours, usually on a cm scale are due to differing amounts and oxidation states of Fe-containing minerals: haematite, magnetite, grunerite, limonite, siderite and sometimes pyrite. BIF is not forming today and although it can be found in the Archean, most deposits of BIF were formed around 2 billion years ago. |
|