A 10,600 year pollen record from Nong Thale Song Hong, Trang Province, south Thailand

Abstract

Although long occupancy of south Thailand has been recorded at Lang Rongrien rock shelter, little detailed palaeoenvironmental work has been published from the peninsula. This account begins to rectify the situation using palynology and microfossil charcoal analyses from a core extracted at Nong Thale Song Hong. Interpretation of the results is difficult, and there are unresolved inconsistencies in the radiocarbon dates. The fire record is longer than expected, given the latitude of the site, and the vegetation was never stable for long, probably due to hydrological changes, altering climate and soils, as well as human impact. The topography makes the site more useful for tracing local vegetation changes and lake level variations than oscillations in regional vegetation. Introduction: location and physical background Nong Thale Song Hong is a shallow bean-shaped lake located at 7° 52 N., 99° 28'50 E. (Figure 1) north of Trang, south Thailand. The sediment core was collected by Dr Lisa Kealhofer (College of William & Mary, Virginia) and Dr Joyce White (University of Pennsylvania Museum) in December 1994. The site is at c. lOOm altitude and has no inflowing or outflowing streams and the core was extracted from the deepest part of the lake, but borings were not made to determine the spatial variations of the stratigraphy. The highest point in the nearby region is at about 400m altitude, around 14 km south west of the lake. Nong Thale Song Hong is located in an area of acid to-moderately-acid shales, sandstones and sandy shales of the Kanchanaburi Series (Figure 2) which have often been metamorphosed to phyllites, argillites, quartzites and slates (National Resource Atlas 1969). The Kanchanaburi Series ranges in age from the Early Carboniferous to Devonian and Silurian. The soils near the site are red-yellow podzolics Journal of the Siam Society, Vol. 86, Parts 1 & 2 (Figure 1). Red yellow podzolics correlate roughly with the ferrugineous soils of French and Belgian soil classifications (Young 1976) and have some weatherable minerals remaining, so they are more chemically fertile than ferrallitic soils. They form under seasonally dry climatic conditions, while ferrallitic soils develop under ever-wet conditions. Red-yellow podzolic soils commonly occur under various types of wooded savanna vegetation whereas ferrallitic soils are characteristic of humid tropical rainforest areas. The 1:50,000 soil map for the area shows the site to be surrounded by the Fang Daeng soil series. To the north, in the hills, soils series 104, 'slope complex' (colluvial soils) occurs, while the other soil series in the vicinity is the Kho Hong 'mottled association'. The fact that the Kho Hong association is mottled confirms that there has been drying out, with oxidising conditions replacing reducing conditions. • School of Archaeology and Palaeoecology. The Queen's University, Belfast BTI INN, Northern Ireland, UK