Abstract
The abundance of diatom remains in quaternary lacustrine sediments was estimated by counting under the inverted microscope. Infrared analysis was performed on the same sediment samples in order to quantify the biogenic silica content. Agreement between the numbers of frustules and amount of biogenic silica shows (1) that the counting method is a useful tool for determining the diatom content in sediments, (2) that direct physical measurements are necessary for a precise evaluation of the diatom contribution to the sediments.