Tree throw

A tree throw or tree hole is a bowl-shapped cavity or depression created in the subsoil by a tree.

They are formed either by the long term presence and growth of tree roots or when a large tree is blown over or has its stump pulled out which tears out a quantity of soil along with the roots. The resultant hole will often slowly fill with organic material and can be identified during archaeological fieldwork. Some tree throws recorded during excavations can be very old indeed.

Fresh tree throws also provide a degree of shelter amongst the roots for animals. Some also contain evidence of prehistoric human activity such as flint tools suggesting that they were sometimes used by people in the distant past.

Source

Darvill, T (ed.) (2003). Oxford Concise Dictionary of Archaeology, Oxford: Oxford University Press. ISBN 0192800051.