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7302786 
Journal Article 
Indialite-rich paralava from a coalmine waste-dump, Sosnowiec, Poland 
Gaweda, A; Janeczek, J; Kierepka, M; Kadziolko-Gawel, M; Krzykawski, T 
2013 
Neues Jahrbuch fuer Mineralogie. Abhandlungen
ISSN: 0077-7757 
190 
237-251 
High-temperature (>1000 degrees C) melting and pyrometamorphism of Carboniferous psammitic-pelitic rocks caused by spontaneous combustion of coal in a coal mine waste dump, Sosnowiec, Poland, produced paralava and clinker. Local differences in oxygen fugacity, melt density and viscosity led to the formation of two varieties of paralavas both with andesitic composition: reduced (dark grey) and oxidized (red). Abundant Fe-rich idiomorphic indialite (X-Fe = 0.47-0.63) occurs in reduced paralava together with spinel, magnetite, hematite, rare phosphides, minor Fe-rich sapphirine and relic pyrite, monazite, xenotime, and zircon. Only few acicular crystals of indialite, skeletal spinel, and hematite occur in the oxidized paralava in addition to abundant partially resorbed quartz inherited from the sedimentary protolith. Partial melting of monazite under reducing conditions did not reset its U-Th-Pb ages despite mobilization of P and subsequent precipitation of secondary (Fe, Mn, Mg, Ca)-phosphides. Fractional crystallization combined with redox conditions was a major mechanism controlling mineral and chemical compositions of paralava. 
paralava; indialite; oxygen fugacity; pyrometamorphism