<![CDATA[Coal quality is affected by the depositional environment, characteristics of organic matter, and input of clastic sediments during peat formation. Although the link between depositional environment and coal quality has been widely studied in various coal basins, research that combines petrographic analysis, coal facies (TPI-GI and VI-GWI), coal quality, and geostatistics to assess the geological control over coal quality distribution in the Sinamar Formation remains very limited. This study aims to interpret the coal deposition environment of Seam C and analyze how the deposition environment relates to variations in coal quality in the Leban area, Jambi Province. The methods involved proximate and ultimate analysis, petrography, coal facies interpretation using the Tissue Preservation Index (TPI), Gelification Index (GI), Vegetation Index (VI), and Groundwater Index (GWI), along with descriptive statistics and spatial modeling with Ordinary Kriging based on 47 drilling data points. The findings show that Seam C coal has an average ash content of 6.60 %, total sulfur of 0.70 %, moisture of 12.14 %, and a calorific value of 6324.74 kcal/kg. Petrographic analysis reveals a dominance of vitrinite maceral with vitrinite reflectance between 0.44-0.46 %, while coal facies analysis indicates that most samples from the WBS, LMH, and AKA sites formed in an Upper Delta Plain environment with telmatic to wet forest swamp facies. Meanwhile, the BA1 site developed in a Lower Delta Plain environment with marsh facies, influenced by a higher influx of clastic sediments. Spatial analysis shows increased ash and sulfur levels in the northern part of the study area, while calorific value tends to be higher in the southwest. The results suggest that variations in Seam C coal quality are mainly controlled by changes in depositional facies, while the degree of coalification remains relatively uniform across the study area. The novelty of this research lies in its integrated approach, combining petrographic analysis, coal facies, coal quality, and geostatistics to explore the relationship between depositional environment and the spatial distribution of coal quality in the Sinamar Formation. This method offers a more complete understanding of the geological factors influencing coal quality and can support resource evaluation and coal exploration planning in the Sinamar Formation and other coal basins with similar features.]]>
