Editing Archaeological excavation (section)

==Finds processing==
Finds and artifacts that survive in the archaeological record are retrieved in the main by hand and observation as the context they survive in is excavated. Several other techniques are available depending on suitability and time constraints. Sieving (screening) and [[Flotation (archaeology)|flotation]] are used to maximize the recovery of small items such as small shards of pottery or flint flakes, or bones and seeds.

=== Flotation ===
Flotation is a process of retrieval that works by passing spoil onto the surface of water and separating finds that float from the spoil which sinks. This is especially suited to the recovery of environmental data stored in organic material such as seeds and small bones.<ref>{{Cite web|date=2019-09-06|title=What is Archaeological Flotation?|url=http://zagoraarchaeologicalproject.org/2019/09/06/what-is-archaeological-flotation/|access-date=2020-07-29|website=Zagora Archaeological Project|language=en-US}}</ref> Not all finds retrieval is done during excavation and some, especially flotation, may take place post-excavation from samples taken during excavation.

=== Sieving ===
[[File:Sållning i Bagarstugan - Skällviks borg.webm|thumb|Sieving during an excavation in Sweden.]]
The use of sieving (screening) is more common on research-based excavations where more time is available. Some success has been achieved with the use of cement mixers and bulk sieving. This method allows the quick removal of context by shovel and mattock yet allows for a high retrieval rate. Spoil is shoveled into cement mixers and water added to form a slurry which is then poured through a large screen mesh. The speed of this technique is offset by the damage it does to more fragile artifacts. 

=== Spot Dating ===
One important role of finds retrieval during excavation is the role of specialists to provide [[spot dating]] information on the contexts being removed from the archaeological record. This can provide advance warning of potential discoveries to come by virtue of [[Stratigraphy (archaeology)#Residual and intrusive finds|residual finds]] redeposited in contexts higher in the [[Sequence (archaeological)|sequence]] (which should be coming offsite earlier than contexts from early eras and phases). Spot dating also forms part of a confirmation process, of assessing the validity of the working hypothesis on the phasing of site during excavation. For example, the presence of an anomalous [[medieval]] pottery [[sherd]] in what was thought to be an Iron Age ditch feature could radically alter onsite thinking on the correct strategy for digging a site and save a lot of information being lost due to incorrect assumptions about the nature of the deposits which will be destroyed by the excavation process and in turn, limit the site's potential for revealing information for post-excavation specialists. Or anomalous information could show up errors in excavation such as "undercutting". [[Chronological dating|Dating methodology]] in part relies on accurate excavation and in this sense the two activities become interdependent.