Features structure of iron-bearing strata's of the Bakchar deposit, Western Siberia

9th All Russian petrographic conference with international participation: Petrology of magmatic and metamorphic complexes

Asochakova, E.M.^1

Department of Geology and Geography, Tomsk State University, Lenina Avenue, 36, Tomsk

634050, Russia^1

关键词: Bearing strata;    Elevated concentrations;    Harmful impurities;    Mineral composition;    Tectonic fractures;    Textural heterogeneities;    Valuable metals;    Western siberia;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/110/1/012002/pdf
DOI  :  10.1088/1755-1315/110/1/012002

来源: IOP

【 摘 要 】

The ore-bearing strata's of Bakchar deposit have complicated structural-textural heterogeneity and variable mineral composition. This deposit is one of the most promising areas of localization of sedimentary iron ore. The ore-bearing strata's are composed mainly of sandstones (sometimes with ferruginous pebbles, less often conglomerates), siltstones and clays. The ironstones are classified according to their lithology and geochemistry into three types: goethite-hydrogoethitic oolitic, glauconite-chloritic and transitional (intermediate) type iron ores. The mineral composition includes many different minerals: terrigenous, authigenic and clayey. Ironstones are characterized by elevated concentrations of many rare and valuable metals present in them as trace elements, additionally alloying (Mn, V, Cr, Ti, Zr, Mo, etc.) and harmful impurities (S, As, Cu, Pb, Zn, P). There are prerequisites for the influence of numerous factors, such as prolonged transgression of the sea, swamping of paleo-river deltas, the appearance of a tectonic fracture zone associated with active bottom tectonics and unloading of catagenetic waters, regression and natural ore enrichment due to the re-washing of slightly-iron rocks. These factors are reflected in the structure of the ore-bearing strata in which rhythmic cycles of ore sedimentation with successive changes in them are distinguished by an association of different mineral composition.