Lanscaper and Geophysical Services

Archaeological Geophysics

Archaeological and environmental impact assessments as part of planning applications often require a geophysical survey. The geophysical survey is designed to detect and define archaeological structures and features that may be hidden beneath the soil. Assessments normally take place in advance of projects such as road or pipe corridors, the building of single houses or estates and the development of industrial zones or mineral extraction sites.

In the case of research projects and monument delimiting surveys, where there are known or visible archaeological monuments, geophysical surveys can be used to assess their possible hidden sub-surface extension and preservation, preservation potential or to prospect for undiscovered monuments in the locality.

LGS have surveyed sites on behalf of a wide range of clients including academic researchers, archaeological contractors, architects, engineers, developers, government agencies and private individuals. Our resources, facilities and expertise offer clients a reliable service that produces cost effective solutions.

Geophysical Techniques

The choice of geophysical technique(s) and survey strategy will depend on the objectives of the assessment or project and the site or area in which it is located. There are a number of techniques commonly used in archaeological geophysics :

A comprehensive geophysical assessment of a site or area is enhanced by using multiple techniques as it has been found that no single technique will respond to all detectable sub-surface features. In consultation with the client we research and design each survey to suit the often unique circumstances of a particular project and/or site.

Topography	Magnetic Susceptibility
Magnetic Gradiometry	Earth Resistance
Multiple survey techniques on the summit of Rathcroghan Mound (after Barton and Fenwick, 2005)

Geophysical surveys can be used in the assessment of :

Commercial / Industrial Developments
Housing Development (both large and small scale)
Road / Pipeline Corridors
Archaeological Research Areas and Sites

Geophysical techniques can be deployed using two methodologies; reconnaissance and/or detailed surveys. Depending on the project objective and the nature of the survey area, these methodologies can complement each other to offer a cost effective method of assessing a site.
A reconnaissance survey quickly provides a review of the complete site using an appropriate geophysical technique and sampling strategy to identify possible targets or anomalies as they are called. The anomalies are subsequently followed-up with more detailed surveys using multiple techniques.

The main geophysical techniques described can generally be used for both reconnaissance and detailed surveys.

Planning a Geophysical Survey

If you would like to contact us to discuss a possible project, all or some of the following outline information would be useful to help us to assess the suitability of geophysical techniques in fulfilling the project objective(s) :

Purpose of the project – e.g. what are the archaeological questions relating to the site? What is the nature and potential size of sub-surface features being investigated?
Timescale
Site/survey location map and site access
Size and shape of survey area
Natural or manmade structures and features, powerlines, pipes and fences in the survey area not shown on the site/survey map
Topography of the survey area
Land ownership
Current ground cover and anticipated cover at time of survey - e.g. pasture, ploughed, seeded, standing crop, de-sodded, gravel, tarmac etc
Given the above information and some discussion we will assess if a geophysical survey should fulfil your objectives and then draw up a specification and survey strategy. This will then lead to a quotation for the cost of the survey and subsequent reporting.

Contact Details

Landscape and Geophysical Services
Convent Road
Claremorris
County Mayo
Ireland