Lignite deposits, associated with Akli Formation (Paleocene), from the Sonari mine of Barmer Basin, Rajasthan, were investigated by applying organic petrography, palynofacies, and geochemistry in order to understand the origin, nature, and character of these lignite-bearing deposits and to assess their thermal maturation and hydrocarbon generation potentiality. The studied samples contained an abundance of huminite group of macerals (av. 54.0 vol.%) and relatively higher abundance of C₂₇ and C₂₉ n-alkane hydrocarbons. High carbon preference index (CPI: 5.03–9.44) and high terrigenous aquatic ratio (TAR: 5.09–20.01), together with the liptinite macerals (av. 10.3 vol.%), inform the prevailing contribution of higher plants. Besides, the significant amount of detrohuminites (av. 26.8 vol.%) and non-biostructure phytoclasts (av. 42.25%), along with hopanoids, denote a meaningful herbaceous plants input and/or high level of tissue destruction (bacterial activity). The terpenoid composition was mainly constituted by pentacyclic triterpenoids and A-ring-degraded angiosperm-derived compounds and diterpenoids. The inertinite contents (av. 22.3 vol.%) and the pristane/phytane (Pr/Ph) ratio imply the variation in the redox conditions during the accumulation. The petrographic indices revealed that the paleo-flora were accumulated in a limno-telmatic condition, with fluctuating groundwater level. Likewise, the palynofacies data displayed that the peat was deposited in dysoxic-suboxic settings under proximal condition. Subsequently, the incidence of dinoflagellate cysts in the studied samples suggests a marine intrusion. The considerable total of pyrite (up to 16.7 vol.%, comprising framboidal) suggests a coastal swamp condition (marginal marine). The thermal alteration index (TAI: av. 2.15), T_max (av. 411 °C for lignite and 414 °C for associated shale) and the gross calorific values (av. 4601 cal/g) showed the immaturity of the studied samples. The lignites contained low to moderate ash yields (av. 12.57 wt.%) and moisture (av. 12.79 wt.%) contents, whereas the carbon^daf (daf = dry ash-free basis) contents were high (av. 67.22 wt.%) and corroborated well with the inertinite group of macerals. The fuel ratio varied from 0.77 to 1.32. The volatile matter yield^daf (av. 51.09 wt.%), fixed carbon^daf (av. 48.91 wt.%), and the oxygen^daf (av. 22.16 wt.%) contents were moderately high. The total organic carbon contents (TOC: 1.17–54.84 wt.%, av. 24.78 wt.%) and hydrogen index values (HI: 32–361 mg HC/g rock) exhibit that the studied samples mostly have type III kerogen and show an excellent potentiality to generate gaseous hydrocarbons.

通过应用有机岩相学、孢粉相和地球化学研究了与拉贾斯坦邦 Barmer 盆地的 Sonari 矿的 Akli 组（古新世）相关的褐煤矿床，以了解这些褐煤矿床的起源、性质和特征以及评估它们的热成熟度和生烃潜力。所研究的样品含有丰富的腐殖质组（平均 54.0 vol.%）和相对较高丰度的 C ₂₇和 C ₂₉ n-烷烃。高碳偏好指数 (CPI: 5.03–9.44) 和高陆源水生比率 (TAR: 5.09–20.01) 以及 liptinite macerals (av. 10.3 vol.%) 表明高等植物的主要贡献。此外，大量的腐植酸（平均 26.8 vol.%）和非生物结构的植物碎屑（平均 42.25%），连同 hopanoids，表示有意义的草本植物输入和/或高水平的组织破坏（细菌活性）。萜类成分主要由五环三萜类和A环降解的被子植物衍生化合物和二萜类化合物组成。惰性物质含量 (av. 22.3 vol.%) 和姥鲛烷/植烷 (Pr/Ph) 比率意味着在积累过程中氧化还原条件的变化。岩相学指标显示，古植物群在浅海-远程状态下积累，地下水位波动较大。同样，孢粉相数据显示泥炭在近端条件下沉积在缺氧-缺氧环境中。随后，研究样本中甲藻囊肿的发生率表明存在海洋入侵。相当数量的黄铁矿（高达 16.7 vol.%，包括 fmboidal）表明海岸沼泽条件（边缘海洋）。热蚀变指数 (TAI: av. 2.15), 7 vol.%, 包括 framboidal) 表明沿海沼泽条件 (边缘海洋)。热蚀变指数 (TAI: av. 2.15), 7 vol.%, 包括 framboidal) 表明沿海沼泽条件 (边缘海洋)。热蚀变指数 (TAI: av. 2.15),T _max（褐煤平均为 411 °C，伴生页岩为 414 °C）和总热值（平均 4601 cal/g）表明所研究样品的不成熟度。褐煤含有低至中等灰分产量（平均 12.57 重量%）和水分（平均 12.79 重量%）含量，而碳^daf（daf = 干无灰基）含量高（平均 67.22 重量%）。 %) 并与无机质惰性组得到了很好的证实。燃料比从 0.77 变化到 1.32。挥发物产率^daf (av. 51.09 wt.%)、固定碳^daf (av. 48.91 wt.%) 和氧气^daf(av. 22.16 wt.%) 含量适中。总有机碳含量 (TOC: 1.17–54.84 wt.%, av. 24.78 wt.%) 和氢指数值 (HI: 32–361 mg HC/g rock) 表明所研究的样品大多具有 III 型干酪根并显示产生气态碳氢化合物的极好潜力。