Chartered Institute for Archaeologists 2023

P R O F E S S I O N A L A R C H A E O L O G Y | A G U I D E F O R C L I E N T S 2 0 2 3 3 3 CASE STUDIES | MANAGING ARCHAEOLOGY: Evaluation techniques that reduce uncertainty Placing geophysical survey at the centre of archaeological and heritage services Rok Plesnicar, Geophysicist, Nicholas Crabb ACIfA, Senior Geophysicist, and Tom Richardson ACIfA, Terrestrial Geophysics Manager, Wessex Archaeology instruments on vehicle-mounted arrays and integration of GPS/GNSS data enables rapid data collection at very high resolution. This allows entire archaeological sites and landscapes to be mapped at unprecedented levels of detail. As such, it is fair to say that the evolution of geophysical prospection has been one of the most important methodological advances of field archaeology in recent times. At Wessex Archaeology, geophysics is utilised alongside a range of archaeological and heritage services. This enables us to draw upon a breadth of experience and leads to a cohesive approach, where different disciplines meet throughout the lifecycle of a project. As geophysics techniques are often deployed at the outset of a project, this can be critical in helping clients achieve successful planning outcomes, engage communities and stakeholders, and enhance the value of national historical assets. The first stage of archaeological evaluation often involves non-intrusive techniques such as geophysical survey. In this case study, the team from CIfA Registered Organisation Wessex Archaeology outline recent advances in archaeological geophysics and how using the right technique can support positive outcomes for clients and developers. Registered Organisations are led by Members (MCIfAs) and have demonstrated their ability to act ethically and comply with professional standards, assuring clients that the work will meet their needs and be carried out in the public interest. The advent of contemporary digital technologies such as GIS, remote sensing and geophysical survey has had a tremendous impact on archaeological practice. These tools have become commonplace and they enable us to investigate beyond the ‘site’ to consider what is happening within the wider landscape. Geophysical survey, in particular, has made significant technological advances over the last 30 years with new instruments and sampling strategies making fieldwork faster, more sophisticated, and more cost effective. Terrestrial geophysical survey incorporates a variety of non-destructive methods used to identify subsurface variations through the measurement of physical properties of the ground. Each technique has specific advantages and limitations and when deployed in appropriate conditions they can be extremely effective. More recently, the towing of these Typical gradiometer setups used in terrestrial geophysics: A) a handheld Bartington Grad601 dual sensor system; B) a non-magnetic cart mounted Bartington Grad-13 sensors; C) an all-terrain vehicle towed array with SenSys FGM650/3 sensors. In optimal conditions, handheld systems allow for approximately 2 ha of survey data to be collected in a single day, whereas cart-based systems and vehicle-towed systems can facilitate more than 5 ha and 10 ha respectively. ©Wessex Archaeology A B A C