As part of our ongoing look into our specialist services, today we’re talking about geochemical survey.
This is a revolutionary and exciting method that can detect and define areas of archaeological activity, often with zero ground disturbance. When used alongside more conventional methods of investigation, such as geophysical survey or remote sensing, our award-winning approach to using a pXRF (portable X-Ray fluorescence) can help us locate settlements within an landscape, independently confirm archaeologically blank areas and even pin-point areas of activity within a site or rapidly characterise whole landscapes.
The pXRF has been an integral tool when deploying our Land Prospection Service, enabling us to further enhance interpretation of sub-surface anomalies identified through geophysical and UAV-based surveys. Also, the pXRF has been used to identify and interpret archaeological deposits, horizons, and artefacts during excavation, meaning we can refine our excavation or sampling strategy in real time, making a big difference to how we excavate a site and the types of features that we find.
An example of where geochemical survey complemented geophysical techniques is the landscape study at Hindlow Quarry. Geophysics successfully identified a number of features including pits, trackways, railways and a single class of highly magnetic yet poorly defined anomalies that seemed to relate to industrial activity.
Geochemistry allowed the further refinement of this class of anomalies by allowing their differentiation to those associated with high lead or calcium. Areas with elevated lead are best understood as relating to the exploitation or processing of lead mineralization. Anomalies associated with low lead but high calcium were more likely to be associated with lime burning and the presence of a lime kiln. This allowed the further characterisation of the site by identifying the extent of lead and lime extraction across the site.
The ability of the pXRF to discriminate between limestone quarrying and lead processing proved integral to our understanding of the narrative of historic industrial activity across the site.
Find out more about our geochemical analysis services here >