An archaeobotanical flotation photo gallery
Flotation can also be done manually with buckets, sieves and plenty of water without using electricity or fossil fuels. (see step-by-step instructions or a how-to video). Manual bucket flotation has advantages in being highly portable, cheap and can normally be carried out with locally available materials which can be found in markets in the developing world. While variants exist, a simple wash-over method of bucket flotation is reliable and portable. In this method the sample (or part of it, usually 3-5 litres of sediment) is place in a bucket, water is added, and it is stirred up by hand and clods are gently broken down manually. The water is then further stirred and poured over the lip of the bucket into a receiving sieve (often 0.5mm, although 0.25mm may sometimes be preferred) where the flot is caught. Sand and the heavy fraction remain in the bucket. There is certain amount of skill involved in pouring fast enough to coax out the denser charcoal but not too fast so as to pour out fine sands that might clog the mesh.
For another description of bucket flotation, of tea-strainer type, (with images), see that of Cheryl Ward, an archaeobotanist in Florida: here.
Reference collections. It is also important to explore the modern flora and make modern comparative collections. An introduction can be found in a quick how-to video
This page is produced by Dorian Q Fuller. Updated: 6 July 2010