Quantitative interpretation of Cl, Br and I porewater concentration profiles in lake sediments of Loch Lomond, Scotland
One of the four natural analogue sites being investigated by the British Geological Survey is Loch Lomond, in Scotland. Naturally occurring halogen elements (Cl, Br and I) have been migrating from a thin marine horizon into overlying freshwater deposits by a diffusion process which has been occurring for at least 5400 years. This report summarises the main findings accumulated since 1983 when the work was begun, and provides a modelling interpretation of the measured concentration-depth profiles using a new numerical code called Diagen. The release rates of I and Br from the organic matter association in the shallow buried marine layer are very slow; subsequent anion movement by diffusion is affected by tortuosity differences in the sediments rather than by chemical reaction with the sediments. The bulk of the evidence supports conservative transport of iodide, bromide and chloride anions towards the sediment/loch interface. The report discusses some implications of the findings.
Bibliographic Reference: EUR 13310 EN (1991) 56 pp., FS, ECU 6.25
ISBN: ISBN 92-826-0516-7
Record Number: 199110404 / Last updated on: 1994-12-02
Original language: en
Available languages: en