Effect of Organic Matter on the Color of Sphalerite from the Silesia-Cracow Lead-Zinc Deposits, Poland

Abstract

Abstract. Using gas chromatography-mass spectrometry (GC-MS) sphalerite samples from lead and zinc mines of the Silesian-Cracow region were studied in terms of the effect of organic matter on their coloration. The results indicate no correlation between the abundance and chemical composition of organic matter and sphalerite coloration. TOC values for investigated samples are in the range of 0.5-1.28%. A basic feature characterizing all samples is very similar distribution of n-alkanes, with a predominance of short-chain n-alkanes (from n-C 13 to n-C 21 ) over long-chain n-alkanes (from n-C 25 to n-C 35 ). Among the isoprenoids pristane dominates over phytane (Pr/Ph ratio in one sample is even 8.95), which does not correspond to previous studies (Karwowski et al. 2001) and may be due to the multi-source nature of organic matter present in sphalerite inclusions from the Silesian-Cracow Zn-Pb deposits. The occurrence of hopanes with 17β,21β(H) stereochemistry indicates a low maturity of test samples.