page_title: Iron-rich sedimentary rocks
section_title: Banded iron formations
hierarchical_section_title: Iron-rich sedimentary rocks / Banded iron formations vs. granular iron formations / Banded iron formations
caption_attribution_description: English: This image shows a 2.1 billion year old rock containing black-banded ironstone. The rock weighs about 8.5 tons, and is approximately two meters high, three meters wide, and one meter thick. It was found in North America and belongs to the National Museum of Mineralogy and Geology, Dresden, Germany. The rock is located at +51°2'34.84" +13°45'26.67". Deutsch: Dieses Bild zeigt einen etwa 8,5 Tonnen schweren und 2,1 Milliarden Jahre alten Block mit Bändereisenerzen. Der etwa zwei Meter hohe, drei Meter breite und einen Meter tiefe Gesteinsblock wurde in Nordamerika gefunden und gehört dem Staatlichen Museum für Mineralogie und Geologie Dresden. Der Block befindet sich bei den Koordinaten +51°2'34.84" +13°45'26.67". Português: Imagem duma antiga rocha de 8,5 toneladas de 2,1 biliões de anos, com faixas de minério de ferro. Este bloco de pedra de aproximadamente dois metros de altura, três de largura e um de espessura foi encontrado no norte da América e encontra-se em exposição no Museu Nacional de Mineralogia e Geologia em Dresden, Alemanha, em +51°2'34.84"N +13°45'26.67"E. Italiano: Questa immagine mostra una roccia vecchia di 2,1 miliardi di anni, contenente orizzonti ferriferi a bande , che pesa circa 8,5 tonnellate. Approssimatamente la pietra è alta due metri, larga tre e spessa un metro,fu trovata in Nord America e appartiene al Museo Nazionale di Mineralogia e Geologia a Dresda, in Germania. La roccia è situata a latitudine +51°2'34.84" N e longitudine +13°45'26.67" E. Русский: Здесь изображена скала возрастом 2,1 миллиарда лет, содержащую железную руду с черной каймой, вес камня приблизительно 8,5 тонн. Приблизительно два метра высотой, три метра шириной, и один метр толщиной камень был найден в Северной Америке и принадлежит Национальному музею Минералогии и Геологии в Дрездене, Германия. Скала расположена +51°2'34.84"N +13°45'26.67"E. Camera data Camera Nikon D70 Lens Tamron SP AF 90mm/2.8 Di Macro 1:1 Focal length 90 mm Aperture f/2.8 Exposure time 1/250 s Sensivity ISO 200
context_page_description: Iron-rich sedimentary rocks are sedimentary rocks which contain 15% or more iron. However, most sedimentary rocks contain iron in varying degrees. The majority of these rocks were deposited during specific geologic time periods: The Precambrian, the early Paleozoic, and the middle to late Mesozoic. Overall, they make up a very small portion of the total sedimentary record.
  Iron-rich sedimentary rocks have economic uses as iron ores. Iron deposits have been located on all major continents with the exception of Antarctica. They are a major source of iron and are mined for commercial use. The main iron ores are from the oxide group consisting of hematite, goethite, and magnetite. The carbonate siderite is also typically mined. A productive belt of iron formations is known as an iron range.
context_section_description: Banded iron formations (BIFs) were originally chemical muds and contain well developed thin lamination. They are able to have this lamination due to the lack of burrowers in the Precambrian. BIFs show regular alternating layers that are rich in iron and chert that range in thickness from a few millimeters to a few centimeters. The formation can continue uninterrupted for tens to hundreds of meters stratigraphically. These formations can contain sedimentary structures like cross-bedding, graded bedding, load casts, ripple marks, mud cracks, and erosion channels. In comparison to GIFs, BIFs contain a much larger spectrum of iron minerals, have more reduced facies, and are more abundant.
  BIFs are divided into type categories based on the characteristics related to the nature of their formation and unique physical and chemical properties. Some categories of banded iron formations are the Rapitan type, the Algoma type, and the Superior type.
caption: Superior type banded iron formation, North America[4]
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