download the new for ios Electron 25.3.0

In particular, mineral distribution and composition should not be neglected in coal facies interpretations. The sequence of maceral assemblages thus represents the change of topogenous to ombrogenous peat and the development of a raised peat bog.A comparison between the result of detailed maceral assemblage analysis and the paleodepositional environment as established from coal maceral ratio calculation indicates that the use of coal maceral ratio diagrams developed for other coal deposits fails to deduce paleo-peat development for these young tropical coals. These groups are the counterparts of fibric peat at the top of the modern peats.

The top section of the coal seams is typically represented by the humodetrinite-rich or inertinite-rich group. The precursors of these groups were hemic and fine hemic peats. The middle section of the seams is characterized by humotelinite-rich and humocollinite-rich groups. This section might be derived from sapric or fine hemic peat often occurring at the base of modern peats. The basal section of the studied coal seams is represented typically by the humodetrinite–liptinite-rich group. Comparing the distribution of maceral assemblages to the maceral or pre-maceral assemblages in modern tropical domed peat in Indonesia reveals many similarities. Minerals are found only in small amounts (0–2 vol.%) mostly as iron sulfide.Based on maceral assemblages, the coals can be grouped into five classes: (1) humotelinite-rich group, (2) humodetrinite-rich group, (3) humocollinite-rich group, (4) inertinite-rich group and (5) humodetrinite–liptinite-rich group. The studied low rank coals have a mean random huminite reflectance between 0.35% and 0.46% and are dominated by huminite (34.6–94.6 vol.%). Results of an organic petrography study on coals from Tanjung Enim, South Sumatra Basin are reported. The South Sumatra basin is among the most important coal producing basins in Indonesia.

Download the new for ios Electron 25.3.0