A sequence of banded iron formation rocks that are exposed in the Gunflint Range of northern Minnesota and northwestern Ontario along the north shore of Lake Superior. (term) The gunflint chert
ABSTRACT: Muro Banded IronFormation occurs in the Proterozoic Toto Schist Belt, central Nigeria. It consists preponderantly of oxide facies and minor carbonate facies. The oxide facies is made up of alternating bands of quartz (metachert) with those of hematite + magnetite + martite ± goethite, chlorite, pyrrhotite and garnet.
These stilpnomelane microgranules are rel atively uncommon but has been observed in Superiortype BIF in the Lake Superior region, Canada (Van Hise and Leith, 1911), in the Kuruman Iron Formation, South Africa (Beukes, 1973) and in the Brockman Iron Formation, Western Australia (Ayres, 1972; Krapezˇ et al., 2003).
Banded ironformation (BIF), the precursor to low and highgrade BIFhosted iron ore, consists of Archean and Paleoproterozoic Algomatype BIF ( Serra Norte iron ore district in the Carajás Mineral Province), Proterozoic Lake Superiortype BIF ( deposits in the Hamersley Province), and Neoproterozoic Rapitantype BIF ( the Urucum iron ore district) (see the review of the BIFhosted .
a. Banded Iron Formation in the Lake Superior Region of Canada and the US b. Metals such as nickel from the Sudbury Complex in Ontario that is probably the result of a meteorite impact. c. Platinum and other metals from Bushveld complex, a layered mafic intrusion in South Africa d.
Accordingly, the Lake Superiortype BIFs were deposited on stable continental platforms, and Algomatype BIFs are associated with volcanic rocks and were deposited in arc or rift settings. A third BIF type, exclusively Neoproterozoic in age, is the Rapitan type (, Beukes and Klein, 1992), and is characterized by a glacially influenced ...
and Lake Superior banded cherty ironformations are atypical and represent the products of the termination of banded ironformation deposition. The Australian, Hamersley and South African Transvaal deposits are believed to be more normal and were produced by biological and inorganic activity under an anoxygenous atmosphere,
The classic Lake Superior banded ironformations, including those in the Marquette, Gogebic, Mesabi and Gunflint Iron Ranges, formed in that sea. The newly established subduction zone caused continued arc volcanism until about 1850 Ma when a fragment of Archean crust, now the basement of the Marshfield terrane, arrived at the subduction zone.
shallow sea rift basins on top of the older Archean rocks (2, 4; Figure 2). The Superiortype banded iron formations of the Lake Superior region were deposited during this episode. While these sedimentary rocks were deposited in northern Minnesota and Michigan's Upper Peninsula, to the south in Wisconsin a volcanic arc was
The appearance of Lake Superior type banded ion formation associated with dolomite, quartzite, and black shale, the deposition of manganese ore and the occurrence of large phosphate repository during the Plaeoproterozoic; the onset of BIF with phosphate deposition and sedimentary manganese deposits and cap dolomite during the Neoproterozoic; the penecontemporary formation of oolitic iron stone .
Ore minerals: mostly the iron oxide minerals magnetite and hematite. In some places (not in the Lake Superior region) iron carbonates Waste minerals (tailings): a wide variety of silica (chert, jasper), iron carbonate minerals, iron silicate minerals, in places small amounts of sulfide minerals.
The Lake Superior region was a warm ocean basin, and in the deep, calm areas of the ocean, this alternating sedimentation occurred. Most believe this was from cyanobacteria that used Fe+ in the water as a metabolic aid, which was later expelled with oxygen, to create the iron oxide bands.
orogenic sedimentary assemblages, including a Lake Superior type banded iron formations (4) the Itacolomi Group, composed of sandstones and conglomerates. The QF mining district is the most important gold and iron producer in Brazil. (Alkimin and Noce, 2006). Historical production and present gold reserves exceed t.
These are overlain by the Cauê Formation, Lake Superiortype banded iron formations which are in turn overlain by carbonates of the Gandarela Formation and shallow water to deltaic sediments of the Piracicaba Group.
The base of the exposed iron formation is composed of three lithofacies, including lower clastics that grade into the overlying banded iron formation that in turn grades upward into granular iron formation. This succession is capped by chloritic metadiabases .
Banded Iron Formations (often referred to as BIF) such as this specimen are Precambrian sedimentary rocks that can be up to billion years old. These BIFs are cited as evidence for early life on earth, as oxygen produced by oxygenproducing cyanobacteria in the ocean would have complexed with the dissolved iron to make iron oxides in these rocks.
South India. Major, trace and rare earth elements (REE) chemistry of the banded iron formation of KavuthimalaiVediyappanmalai area, North Arcot district, Tamil Nadu region are utilized to compare with other world BIF and explore that this a separate type of Tamil Nadu type. The petrographic
Types of Anorthosite are Proterozoic Anorthosite and Archean Anorthosite whereas the types of Banded iron formation are Algomatype, Lake Superiortype, Superiortype and historic times, some rocks depending on their hardness were used to create Pictographs and Petroglyphs.
Deposit Types. The Labrador iron deposits are composed of iron formations of the Lake Superiortype. The Lake Superiortype iron formation consists of banded sedimentary rocks composed principally of bands of iron oxides, magnetite and hematite within quartz (chert)rich rock, with variable amounts of silicate, carbonate and sulphide lithofacies.
Microfossils of microbes similar to cyanobacteria, Gunflint Formation, north shore of Lake Superior, billion years old The Gunflint chert ( Ga [1] ) is a sequence of banded iron formation rocks that are exposed in the Gunflint Range of northern Minnesota and .
The Lake Superior agate is a type of agate stained by iron and found on the shores of Lake Superior. The Lake Superior agate differs from other agates found around the world in its rich red, orange, and yellow coloring. This color scheme is caused by the oxidation of iron. Iron leached from rocks provided the pigment that gives the gemstone its beautiful array of color.