Most archaeological field investigations associated with land development are a three-step process. These processes are known as Phase I (Identification), Phase II (Evaluation) and Phase III (Mitigation/Data Recovery).
Phase I (Identification)
Purpose: Determine presence or absence of an archaeological site in the area.
- Relevant background research of area.
- Walkover systematic surface survey.
- Subsurface testing, usually in the form of shovel test pits, at regular intervals along evenly-spaced transects.
- Written report indicating the results of the survey and recommendations for further research and testing. If significant cultural materials have been located during the survey, archaeologists may recommend moving on to Phase II.
Phase II (Evaluation)
Purpose: Determine historical and cultural significance of archaeological materials located during Phase I survey.
- Digging of additional shovel test pits at shorter intervals.
- Delineation of site boundaries based on Phase I and Phase II shovel tests.
- Systematic excavation of test units to collect data on cultural background and stratigraphy of site.
- Possible use of additional testing methods, such as carbon-14 dating, geophysical remote sensing, and collection of flotation samples.
- Determination of site’s preservation and research potential.
- Written report indicating results of Phase I and Phase II surveys and recommendation for or against further research through Phase III.
Phase III (Mitigation/Data Recovery)
Purpose: Full-scale excavation and data recovery of site.
- Phase III data recovery is specifically tailored to fit the research needs of each site.
- Generally speaking, it is a highly-intensive version of Phase II, incorporating significantly more excavation, testing, mapping, and analysis of cultural material found on the site.
- Writing of official archaeological report and submission to proper agencies (e.g., State Historic Preservation Office).