Developers’ guide to archaeological evaluation by borehole
Evaluating a proposed development site
Along with geophysical survey and trial trenching, archaeological investigation using boreholes is another method of evaluating a proposed development site for the presence of buried archaeological remains.
This can be done in two ways.
- Boreholes can be employed for purely archaeological reasons under the control of an archaeologist
- Boreholes which are being drilled under the control of a geotechnical engineer, for example to identify contaminated ground, can also be monitored by an archaeologist.
Made ground – the differences
In geotechnical engineering, any deposits which are not natural substrate are known as ‘made ground’ but to an archaeologist that ‘made ground’ may contain evidence of past human activity or environmental material (known in the profession as ‘palaeo-environmental’ material) which provides an indication of the potential archaeological remains within a development site.
Cost-effective and reliable
Using archaeological boreholes and geotechnical boreholes can be a cost-effective and fairly reliable method of gauging the depth, type, date and significance of archaeological and/or palaeo-environmental deposits present.
On the basis of this information not only is the potential risk to development identified at an early stage but a developer is able to allow for and budget for further archaeological investigation, should it be required, in an organised and timely manner.
When boreholes can prove to be particularly useful
There are particular circumstances where archaeological evaluation using boreholes is especially useful. For example, on urban sites where space is restricted and where archaeological deposits are often very deep, boreholes can be a far more appropriate method of evaluation than trial trenches which not only produce substantial quantities of spoil which has to be managed but also need to be stepped or shored if they go to depth.
This can be time consuming and costly.
From the results of a borehole evaluation, a predictive deposit model can be prepared.
Topics for developers’ guide
- desk-based research
- aerial photography and lidar
- cartographic analysis
- review of geotechnical data and deposit modelling
- and more…