Sulfur stable isotope signatures are instrumental in tracing the sources and tracking the movement of sulfur in different environmental compartments, besides providing vital insights into the origin and transport dynamics. Sulfur stable isotope composition in coal can give valuable information regarding sulfur sources and the process of sulfur incorporation in coal. The present study was conducted to determine the total sulfur content and sulfur isotopic composition for bulk sulfur (bulk S δS) in Oligocene and Eocene coal samples from coal mines and a few coal stockings in northeast India. The results revealed that the total sulfur content in coal samples varied between 1.03 and 4.80 (wt%) with an average value of 2.64 wt%. The bulk S δS in coal samples exhibited a wide range between −4.66 ‰ to 14.78 ‰ (VCDT). Oligocene coal samples from mines in Arunachal Pradesh, Assam, and Nagaland were enriched with heavier sulfur isotopes relative to Eocene coal samples from the Jaintia Hills region of Meghalaya. A moderate positive correlation was observed in the Oligocene coal samples, in contrast to the moderate negative correlation found in the Eocene coal samples. The bulk S δS values and sulfur content in coal samples from coal stockings matched closely with Assam and Meghalaya mine samples. The findings of this study can be used to track the sources and movement of coal sulfur in various environmental compartments, besides providing valuable information about sulfur sources, the process of sulfur incorporation in coal, and the depositional environment.

中文翻译：

---

印度东北部古近纪煤中的硫稳定同位素


硫稳定同位素特征除了提供对起源和运输动态的重要见解外，还有助于追踪硫的来源和跟踪不同环境区域中硫的运动。煤中硫稳定同位素组成可以提供有关硫源和硫在煤中掺入过程的有价值的信息。本研究的目的是测定来自印度东北部煤矿和一些煤矿的渐新世和始新世煤炭样品中散装硫（散装 S δS）的总硫含量和硫同位素组成。结果显示，煤样中的总硫含量在 1.03 至 4.80 (wt%) 之间变化，平均值为 2.64 wt%。煤样中的整体S δS 表现出-4.66 ‰ 至14.78 ‰ (VCDT) 之间的宽范围。与梅加拉亚邦贾因蒂亚山地区的始新世煤样相比，阿鲁纳恰尔邦、阿萨姆邦和那加兰邦矿山的渐新世煤样富含更重的硫同位素。在渐新世煤样中观察到中度正相关，而在始新世煤样中发现中度负相关。煤库煤样中的整体 S δS 值和硫含量与阿萨姆邦和梅加拉亚邦矿样密切匹配。这项研究的结果除了提供有关硫源、硫在煤中掺入过程和沉积环境的宝贵信息外，还可用于跟踪不同环境区划中煤硫的来源和运动。