Definition of black block
Black block is a term used for black, soot-rich parts of burning coal-mining dumps, that underwent thermal transformations by low fO2 conditions. Gaseous jets migrating through these zones are highly reduced (rich in hydrocarbons, CO, and possibly metallorganic compounds). Black blocks are often seen as seams, but may have more isometric shape. The zones are interesting for yielding a "meteoritic association", with minerals like murashkoite (FeP), celsian BaAl2Si2O8, graphite, pyrite.
Refs.:
Sokol, E.V., Maksimova, N.V., Nigmatulina, E.N., Sharygin, V.V., Kalugin, V.M. (2005): Combustion metamorphism. Publishing House of the SB RAS - Novosibirsk, 284 pp. [in Russian, with parts in English]
Kruszewski, Ł., Ciesielczuk, J., Misz-Kennan, M. (2012): What have meteorites to do with coal fires? A case of Upper and Lower Silesian Basins. Mineralogia Special Papers 40: 28-30
Refs.:
Sokol, E.V., Maksimova, N.V., Nigmatulina, E.N., Sharygin, V.V., Kalugin, V.M. (2005): Combustion metamorphism. Publishing House of the SB RAS - Novosibirsk, 284 pp. [in Russian, with parts in English]
Kruszewski, Ł., Ciesielczuk, J., Misz-Kennan, M. (2012): What have meteorites to do with coal fires? A case of Upper and Lower Silesian Basins. Mineralogia Special Papers 40: 28-30