The location of uranium in source rocks and sites of secondary deposition at the Needle's Eye natural analogue site, Dumfries and Galloway
The British Geological Survey has been conducting a coordinated research programme at the natural analogue site of Needle's Eye at Southwick on the Solway coast in south-west Scotland. This study of a naturally radioactive geochemical system has been carried out with the aim of improving predictive models of radionuclide migration in the geosphere. This report describes results of integrated mineralogical studies of both the source-term and sites of secondary accumulation of uranium. Pitchblende in a polymetallic-carbonate breccia vein exposed in ancient sea-cliffs is the main source of labile uranium although other uranium-bearing minerals in the host-rocks present probable ancillary leachable sites. In keeping with the complex chemistry of the primary sulphide-rich mineralisation, a large variety of secondary uranium minerals has been recorded. Uranium transported in groundwaters draining the cliffs has accumulated in organic-rich estuarine/intertidal mudflat sediments of Quaternary age. Charged particle track registration techniques have demonstrated the effectiveness of humified organic matter in retarding uranium transport and, coupled with scanning electron microscopy, have indicated the important role of living plants and bacteria in uranium uptake and concentration.
Bibliographic Reference: EUR 13279 EN (1991) 56 pp., FS, ECU 6.25
ISBN: ISBN 92-826-2421-8
Record Number: 199110583 / Last updated on: 1994-12-02
Original language: en
Available languages: en