Isotopic evidence for the source of sulfur in the Upper Freeport coal bed (west-central Pennsylvania, U.S.A.)

Peat-Forming Environments and Evolution of Thick Coal Seam in Shengli Coalfield, China: Evidence from Geochemistry, Coal Petrology, and Palynology

“…Low-sulfur peat or coals (sulfur content generally lower than 1.0 wt %) have been found in association with terrestrial deposits [67][68][69]. Table 1 shows that most of the coal samples in this study had intermediate sulfur contents (1-3 wt %).…”

“…Organic δ 34 S in 70 sets of data from the total 116 data, including the three investigated coals, were higher than pyritic δ 34 S, and 48 sets of data were the opposite, with the remaining one being equal (Figure 10). Several researchers have stated that pyrite has lower δ 34 S values as a result of isotopic fractionation accompanying microbial sulfate reduction [67,69]. Namely, syngeneic pyritic δ 34 S values should be lower or equal to those of syngeneic organic sulfur.…”

“…However, Figure 11 presents an opposite relationship, which does not support a source from surface or groundwater. Moreover, the pyritic δ 34 S enrichment (7.5-37.5 o / oo ) and high δ 34 S ratio of pyritic sulfur to organic sulfur may have occurred from the fluvial-lacustrine or groundwater systems when compared to those in the original peat mire [67,96]. In addition, most of coals influenced by the marine environment are characterized by the higher organic δ 34 S than pyritic δ 34 S [71,72,[75][76][77].Consequently, The lower pyritic δ 34 S values in the studied coal possibly indicated that it was not mainly caused by fluvial-lacustrine or groundwater systems, but had a marine influence (Figure 10).…”

Sulphur mobility and sulphur‐mineral precipitation during early Miocene‐Recent uplift and sedimentation in Central Otago, New Zealand

“…Lignite seams within the Dunstan and Wedderburn Formations typically have low total sulphur contents (<2 wt%), but those in Hogburn Formation contain up to 7 wt% locally (Park 1910;Williamson 1939;Black 1982) (Table 1). Hogburn Formation lignites accumulated shortly before marine transgression, and high sulphur contents in such coals can be attributed largely to reduction of sulphate (of marine origin in this instance) introduced by groundwater during early burial (e.g., Suggate 1959;Spiker et al 1994).…”

“…Sulphur isotope analysis of minerals, groundwater, and surface water has proven useful in placing constraints on sulphur sources and temporal source variations elsewhere (e.g., Smith & Batts 1974;Chivas et al 1991;Spiker et al 1994). This technique could be usefully applied in Central Otago as well but is beyond the scope of this study.…”