FASTRAC Project Executive Summary
A Whole-site First-assessment Toolkit for combined Mineral Resource and Archaeological assessment in Sand and Gravel deposits.
Project dates: 1st July 2007 to 29th February 2008
This project was carried out by teams in 6 institutions led by the following:
Keith Challis, University of Birmingham
Ian Hill, University of Leicester
David Knight, University of Nottingham
Chris Leech, Geomatrix Earth Science
Neil Linford, English Heritage
Barry Smith, British Geological Survey
Duncan Wardrop, Lafarge Aggregates
This project addresses ALSF core objective “developing the capacity to manage aggregate extraction landscapes in the future”, by developing site-assessment methodology.
Ground investigations are essential components of site assessment for both mineral resources, and archaeological remains. The techniques used for both mineral and archaeological assessment are often similar. Since investigations for both purposes must be performed in areas of potential mineral resource, and there is considerable overlap between them, there are potential benefits to mineral operators, heritage protection, and the planning process, in developing a systematic integrated approach to these investigations. It is important to remember that both mineral deposit and archaeology occupy essentially the same physical space, broadly defined as the soil layer. The project has been timely in relation to the very recent emergence of commercial availability of both airborne, and ground geophysical high resolution survey methods. The project team have the combined expertise in the separate new methodologies and data integration. They also have experience of the current practice in extractive industry, heritage protection and planning to assess critically the value of the information gained using the proposed methods.
We have studied two example sites, at Sturton-le-Steeple and Shelford, both in the Trent valley. Both sites combine the presence of a known aggregate resource with known archaeological remains, as well as being part of a populated and worked landscape, with issues such as soil quality, hydrogeology and bio-diversity to be considered.
We have compiled a separate GIS project for each site, combining pre-existing data with new airborne and surface surveys (Chapter 3). Airborne techniques such as Lidar and hyperspectral imagery provide high spatial resolution data (typical 1m or better) for an entire site, extending to hundreds or thousands of metres, and its even broader landscape setting (Chapter 5). Our case studies have demonstrated that such data are applicable in both archaeological (Chapter 4) and mineral prospection (Chapter 6) as well as in developing mitigation strategies (i.e. resource impact assessment). The ability to scan large areas in this way and select areas for searches using geophysical techniques provides a natural hierarchy of methodology. One aim of prospection is to classify the landscape on multiple scales. This project has demonstrated (Chapter 9) the potential to better-define boundaries of mineral deposits and to define areas of prospectivity for both recent and ancient history (Chapter 7).
Confidence in interpretation may be divided into two primary aspects, spatial accuracy, and characterisation. Chapter 8 provides some good examples of the difficulty of establishing reliable locations for some data, particularly using oblique aerial photographs. The benefit of using multiple complementary surveys, all located with DGPS is well demonstrated. Characterisation refers to relating observed variation in a survey parameter to specific physical properties of the ground. Such an ability to uniquely characterise volumes of the subsurface from remote sensing data and geophysical data is still a research objective rather than an established reality. However the systematic integration of precise survey data, which forms the core of this project, is the key to future advances in this area.
If the whole-site assessment methodology is to become a practical tool, it must be cost-effective within the operating constraints of current aggregate extraction. An essential, and attractive feature of the method is that it decreases risk throughout the assessment and development process. Not only will the increased information facilitate the planning process, but the extensive database will be augmented as production develops (Chapter 10), and provide a useful site management tool throughout the life of a quarry.