Porewater and groundwater geochemistry at the Down Ampney fault research site
The importance of faults in mudrocks as groundwater conduits, and as a control on solute transport, was assessed in a Jurassic mudrock, siltstone and limestone sequence at Down Ampney, Gloucestershire. Samples were taken from a borehole array crossing an east-west trending fault, of approximately 48 m northerly downthrow. Squeezing mudrock samples yielded 18.1 to 34.5 % of total porewater, which was analysed for major/trace elements and stable O/H isotope compositions. Fault zone porewaters have greatly increased sulphate concentrations relative to those remote from the fault. Comparisons are made between pore- and groundwater samples from each side of the fault, and from the fault zone. Pore- and groundwater compositions are not simply related, except in the case of sulphate which, in the fault zone, is more diluted in groundwaters.
Bibliographic Reference: EUR 14335 EN (1993) 52 pp., FS, ECU 7.50
ISBN: ISBN 92-826-5241-6
Record Number: 199310322 / Last updated on: 1994-11-29
Original language: en
Available languages: en