DISTRIBUTION PATTERN OF SPOROPOLLEN IN SURFACE SEDIMENTS OF NORTHWESTERN TAIWAN STRAIT AND ITS GEOLOGICAL SIGNIFICANCE

Palynological investigation for 338 surface sediment samples taken from the northwestern Taiwan Strait have been conducted in order to reveal the distribution patterns of pollen and spore. The dissemination process and source area of pollen and spore, as well as the local depositional environment are discussed in this paper. Based on the total, arboreal, herbaceous and fern pollen concentrations, the distribution of surface pollen assemblages could be classified into four regions in NW-SE direction. Pollen abundance is mainly affected by water depth and the grain size of sediments. The distribution of Pinus is influenced by the combined effects of the northeast monsoon and topography, while tropical and subtropical arboreal pollen, such as Quercus, is mainly influenced by coastal currents and rivers. Fern spores exhibited higher abundance, probably influenced by ocean currents, coastal currents and human activities. Herbaceous pollen occurs in high percentage around the coasts close to the source areas. The estuaries and coastal regions are the important depositional zones for terrestrial pollen grains due to flocculation.