Bulletin of the Geological Society of Malaysia, Volume 28, November 1991, pp. 1 – 36
LEMIGAS, P.O. Box 1089/JKT, Cipulir – Kebayoran Lama, Jakarta, 10010 Indonesia
Abstract: Palynology is the only biostratigraphic technique which permits crossfacies correlation, and the only micropalaeontological method for correlation of non-marine sediments. Despite its wide use in Southeast Asia, there is currently very little published information which allows the geologist to assess independently the value of palynology for correlation and dating in this area. It is hoped that this contribution will help to fill this gap, as well as indicate the groundwork which is necessary in order to build up correlation schemes which will be of value in individual basins.
Following a brief review of the history of palynological research in Southeast Asia, differences in approaches to correlation and dating of Tertiary sediments using palynology and other micropalaeontological disciplines are outlined. It is emphasised that in the Tertiary, the application of palynology is principally in correlation rather than dating; ages can often be applied to palynological zones only through independent dating using planktonic microfossils associated within transgressive sequences and distal marine facies.
The resolution of palunological zonation schemes currently applicable to the Southeast Asian region and which are based on age restricted palynomorphs is then discussed. Many of the most important age index palynomorphs actually exhibit varying stratigraphic ranges across the region and these variations can often be explained in terms of tectonic, climatic and other controls. There is some scope for the determination of additional stratigraphic markers, especially in the Palaeogene, but high resolution schemes based on stratigraphically restricted form, if they can be established, will require a great deal of work.
In order to provide palynological schemes of sufficient resolution to solve typical questions raised during petroleum exploration in Southeast Asia, an approach is required which gives greater resolution than is possible through reliance on age restricted palynomorphs alone. The methods and philosophy behind quantitative palynological zonation schemes are outlined and the stratigraphic resolution of quantitative and qualitative methods compared. Quantitative schemes can provide stratigraphic resolution comparable to that of planktonic marine microfossils, and greatly assist in the resolution of stratigraphic problems and search for hydrocarbons in non-marine, marginal marine and some marine depositional sequences.