Greenalite-Chamosite composition, geothermometry and oxygen …
2023年11月16日 · Iron-rich rocks of Orosirian Period in the Chilpi Group on the northern margin of the Bastar Craton, Central India, contain an association of hematite-magnetite-greenalite-chamosite-quartz in oxide-silicate facies. Additionally chert (quartz) and siderite occur in chert and carbonate facies.
Greenalite and its role in the genesis of early Precambrian iron ...
2021年6月1日 · Greenalite nanoparticles are best preserved in very thinly laminated chert in sub-greenschist facies BIFs. The chert acted as a chemically inert cement that inhibited further reactions between greenalite and sediment pore-waters. The chert also minimized sediment compaction during burial.
an association of hematite-magnetite-greenalite-chamosite-quartz in oxide-silicate facies. Additionally chert (quartz) and siderite occur in chert and carbonate facies. Presence of these mineral assemblages was investigated to infer the redox state of the depositional basin.
Calcite/dolomite, siderite, chamosite, stilpnomelane and chlorite occur disseminated in the ground-mass of the clastic rocks. The clasts in the diamictite consist largely of chert and quartzite. The diamictite was probably deposited from floating ice, while the arenaceous beds resulted from sub aqueous gravity mass flows.
(PDF) Greenalite-Chamosite composition, geothermometry and …
Additionally chert (quartz) and Iron-rich rocks of Orosirian Period in the Chilpi Group on the northern margin of the Bastar Craton, Central India, contain an association of hematite-magnetite-greenalite-chamosite-quartz in oxide-silicate facies.
Petrography and geochemistry of the iron-rich rocks in the …
2023年4月1日 · Presence of chamosite, greenalite and siderite in the ironstones of the Chilpi Group, identified during present analysis, provide valuable information regarding the redox state of the shallow sea. Geochemical analyses reveal high concentrations of Fe 2 O 3total and SiO 2 (average ~ 87.85 wt%) in iron-rich bands.
(PDF) Minerals: Glauconites and Green Clays - ResearchGate
2013年12月31日 · The green granule forming clays are glauconitic, odinite, berthierine and berthierine mixed layer clays, or rarely chamosite, all forming where the rate of deposition is slow.
Chapter 11 Precambrian Iron-Formations: Nature, Origin
1992年1月1日 · Chamosite and chlorite, scarce but recognizable constituents in some iron-formations, presumably also formed diagenetically from silicate residues. The origin of chert is a widely researched problem to which little of consequence can be added here.
Greenalite-Chamosite composition, geothermometry and oxygen …
Additionally chert (quartz) and siderite occur in chert and carbonate facies. Presence of these mineral assemblages was investigated to infer the redox state of the depositional basin. The results have indicated formation temperature variation of 116–255 °C (average 198 °C) and log P(O2) between – 37 and – 60 (average –44).
Minimal biomass deposition in banded iron formations inferred …
2019年11月4日 · These cherty layers are distinct from the typical BIF layers in the Dales Gorge sequence, and can be described as ferruginous chert, as they are composed only of chert + stilpnomelane +...
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