Abstract This study is mainly concerned with sulfur isotope (δ34S) values of inorganic sulfur species associated with the North Thrace Basin's coals (Saray and Pinarhisar coalfields). Sulfur isotope analyses were performed on pyritic sulfur, native sulfur, sulfate sulfur (rozenite) and the precipitated sulfate (P-BaSO4) (leached sulfate from the coal). The δ34S values of pyritic sulfur, rozenite, native sulfur and P-BaSO4 samples in Saray coals ranging from −6.9‰ to −37.3‰ are comparable to the δ34S values of Pinarhisar coals which change from −1.1‰ to −59.3‰. A wide range of strong negative δ34S values in both coalfields, particularly in Pinarhisar site, indicate that bacterial sulfate reduction (BSR) and subsequent pyrite formation were the key processes in the peat depositional environments. As in the δ34S values of both coalfield sites, comparable Sr/Ba and Th/U ratios and pyrite forms (cleat filling and partly massive) of the coals imply that besides marine sulfate hydrothermal solutions, originated from volcanism being active during peat accumulation in the basin, also contributed to the sulfur pools in the coal depositional environments. Overall, the δ34S values of inorganic sulfur species, and the largest sulfur isotope fractionation between δ34S P-BaSO4 and the δ34Spyrite, obtained for the first time for the Thrace Coal Basin, suggest that bacterial reduction of sulfate, possibly marine and hydrothermally derived, and subsequent pyrite formation and its fast burial may have been contributed to sulfur budget in the basin.

中文翻译：

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土耳其北色雷斯盆地 Saray 和 Pınarhisar 煤田中黄铁矿和无机硫同位素的来源和分布

摘要 本研究主要关注与北色雷斯盆地煤层（Saray 和 Pinarhisar 煤田）相关的无机硫物种的硫同位素 (δ34S) 值。硫同位素分析是对黄铁矿硫、天然硫、硫酸盐硫（菱锌矿）和沉淀的硫酸盐 (P-BaSO4)（从煤中浸出的硫酸盐）进行的。Saray 煤中黄铁矿硫、菱铁矿、天然硫和 P-BaSO4 样品的 δ34S 值范围为 -6.9‰ 至 -37.3‰，与 Pinarhisar 煤的 δ34S 值（从 -1.1‰ 至 -59.3‰）相当。在两个煤田中，特别是在 Pinarhisar 地点，广泛的强负 δ34S 值表明细菌硫酸盐还原 (BSR) 和随后的黄铁矿形成是泥炭沉积环境中的关键过程。与两个煤田站点的 δ34S 值一样，可比较的 Sr/Ba 和 Th/U 比率以及煤的黄铁矿形式（割理填充和部分块状）意味着除了海相硫酸盐热液溶液外，源自盆地泥炭堆积期间活跃的火山活动，也促成了盆地中的硫库煤沉积环境。总体而言，无机硫物种的 δ34S 值，以及 δ34S P-BaSO4 和 δ34Spyrite 之间最大的硫同位素分馏，这是首次在色雷斯煤矿获得，表明硫酸盐的细菌还原，可能来自海洋和热液，以及随后黄铁矿的形成及其快速埋藏可能是该盆地硫收支的原因。源于盆地泥炭堆积过程中火山活动的活跃，也促成了煤沉积环境中的硫库。总体而言，无机硫物种的 δ34S 值，以及 δ34S P-BaSO4 和 δ34Spyrite 之间最大的硫同位素分馏，这是首次在色雷斯煤矿获得，表明硫酸盐的细菌还原，可能来自海洋和热液，以及随后黄铁矿的形成及其快速埋藏可能是该盆地硫收支的原因。源于盆地泥炭堆积过程中火山活动的活跃，也促成了煤沉积环境中的硫库。总体而言，无机硫物种的 δ34S 值，以及 δ34S P-BaSO4 和 δ34Spyrite 之间最大的硫同位素分馏，这是首次在色雷斯煤矿获得，表明硫酸盐的细菌还原，可能来自海洋和热液，以及随后黄铁矿的形成及其快速埋藏可能是该盆地硫收支的原因。