Flotation Technique in Archaeology
What is it?
Flotation uses water to process soil samples and recover tiny artifacts that would not ordinarily be recovered when screening soil during an archaeological investigation. The reason these artifacts aren’t normally recovered is that they are so tiny that they fall through the ¼” screen typically used by archaeologists to sift the soil.
To recover tiny artifacts, a soil sample is placed on a screen and with the addition of water; artifacts are separate from the dirt particles. Light materials (called light fraction) float on top of the water while heaver materials such as bone, pottery, and stone rest on the screen. Light materials include plant remains, seeds, and insects which can reveal information about diet, environment, and climate.
Heavy and light materials are collected separately and placed on a tray to dry. Once the sample has thoroughly dried, the material is placed in archival bags for storage and further research. Read more