A COMPARISON OF FOUR ABSOLUTE POLLEN PREPARATION TECHNIQUES

Abstract

SUMMARYLaboratory tests were made on three absolute pollen preparation techniques previously published by Davis (1965, 1966), Matthews (1969) and Jørgensen (1967), and on an additional weighing method (Modified Jørgensen) using both standard pollen suspensions and fossil minerogenic samples. Laboratory procedure is described and the following results include an investigation of grain distribution within slides prepared by the Jørgensen and Matthews methods, a discussion of the statistical reliability of the Jørgensen method, and a test of the variability attributable to preparation methods, using the coefficient of variation (C.V.) as the basis of comparision. The relation between grain loss (bias) during the preparation procedure, the methods employed, and the sediment type used is explored, and some practical aspects of the various techniques are considered. It is concluded that for detailed palynological work, particularly in conjunction with 14C dating, the extra time needed in the preparation of the Davis or the Modified Jørgensen methods is balanced by a greater reliability of result. The Matthews and Jørgensen techniques are shown to be adequate for determination of large scale changes in pollen concentration, though all methods would benefit through the addition of an ‘exotic’ pollen type in order to detect losses during preparation.