A spit is archaeological jargon for excavation level. You have to destroy a site while excavating it, and so the excavation must be carefully controlled. Thus, sites are excavated in levels, each excavated level carefully recorded (soil type, presence of stains, artifact count, etc.) before the next one is begun.
The preferred progress in archaeological excavation is by natural strata: in other words, the excavator uses soil changes or structural elements of the excavation for recording the levels. However, in some excavations, natural stratigraphy cannot be followed, because soil changes are too subtle to be determined. In these cases, the site is excavated in arbitrary levels, typically 5- to 10-centimeters in thickness. These arbitrary levels are called spits in some places.
Further Information
This glossary entry is a part of the About.com guide to href="http://archaeology.about.com/od/glossary/Archaeology_Dictionary_Index.htm">Dictionary of Archaeology.
