Petrology of some Indonesian and Australian tertiary coals

Similarities and differences in type and rank characteristics in Tertiary coals of the western part of Indonesia (particularly on the islands of Sumatera and Kalimantan) and eastern Australia (particularly in the Latrobe Valley) reflect their geological setting and influence utilization. Rank and type variation within and between Indonesian and Victorian coals were assessed by pétrographie examination of more than two hundred and fifty samples. Both Indonesian and Victorian coals are dominated by vitrinite, common liptinite and rare inertinite and mineral matter. Vitrinite macérais are dominated by detrovitrinite and telovitrinite. Resinite, cutinite and suberinite are the dominant liptinite macérais in Indonesian coals, whereas liptodetrinite, suberinite and sporinite are the dominant liptinite macérais in Victorian coals. Inertinite macérais in Indonesian and Victorian coals include semifusinite, sclerotinite and inertodetrinite. The type differences largely reflect climatic influence and differences in peat conditions.