Faults in clays - their detection and properties
The `Faults in clays project', a cooperative research effort between Ismes and ENEA of Italy and BGS and Exeter University of the UK, was aimed at assessing and improving the resolution capability of some high resolution geophysical techniques for the detection of discontinuities in clay formations. The selected sites were two quarries in plio-pleistocenic clay formations in central Italy where faults had been observed. At Orte, two 90 m boreholes were drilled and cored. Geophysical work consisted of vertical electrical soundings (VESs) and horizontal electrical lines (HELs), four high resolution seismic reflection lines, and in-hole and cross-hole logs. Laboratory activities consisted of geotechnical characterisation and permeability tests, and measurements of disequilibrium in the uranium decay series. At Narni, where Exeter University sampled soil gases for geochemical analyses, the geophysical work consisted of a geoelectrical survey (five VESs and two HELs), and two high resolution seismic reflection lines. Additional investigations included a structural geology survey. The main conclusion of the research is that current geophysical techniques do not have a resolution capacity sufficient to detect the existence or determine the characteristics of faults in deep homogeneous clay formations.
Bibliographic Reference: EUR 13400 EN (1991) 398 pp., FS, ECU 35
ISBN: ISBN 92-826-2516-8
Record Number: 199110726 / Last updated on: 1994-12-02
Original language: en
Available languages: en