Liptinite in coal and oil source rocks in northern Thailand

Palynological study of northern Thailand coal and oil deposits indicates a similar palynological association to that of the Borneo region. Coal petrog raphic studies of these deposits show variations in the liptinite macerals, especially alginite types. The oldest of these coal and oil deposits, whic h are of Late Oligocene to Early Miocene age, are dominated by Botryococcus sp. or Botryococcus-related algae. Thick-walled lamaginites and spores and pollen of temperate affinity, are found in some areas. By contrast, thin-w alled lamaginite is dominant in late Middle Miocene time. Resinite, suberin ite, and cutinite are dominant in forest swamp coal deposits whereas algini te, cutinite and lycopodium spores are dominant in lacustrine environments. Exsudatinite is common even at early levels of maturation. These liptinite macerals can be major sources of oil and gas. (C) 1999 Elsevier Science Lt d. All rights reserved.