The most common plant-remains in Quaternary deposits are the pollen grains of flowering plants (Spermatophytes) and the spores of ferns (Pteridophytes) or mosses (Bryophytes), all of which are not visible to the naked eye. The morphological diversity of these microscopically small plant parts, usually only a tenth to a hundredth millimetre large (10-100 micrometers), allows the identification of families, genera and sometimes even species. Usually, very large numbers of pollen grains and spores of vascular plants (Cormophytes) are produced. They are then transported by wind and deposited in sediments and peat, where they are well preserved thanks to the prevailing anoxic conditions. The examination of spores and pollen grains therefore not only provides qualitative information on the plants' presence, but also quantitative information on their abundance. Thus, conclusions can be drawn about former vegetation conditions.
The analysis of pollen grains and spores as a method of investigating Quaternary (or older) deposits, represents part of Palynology. Palynology can be translated literally as 'the science of floating dust particles in the air', in this case 'dust' refers to pollen.