General Discussion

Abstract

The discussion on this topic proved to be most wide-ranging. Particular interest was developed in the question of assessing seismic behaviour in reservoir basins prior to impounding. There was general agreement that this was a particularly difficult matter for an engineering geologist to assess without specialist advice from a seismologist. Attention was drawn to the situation in many areas which were thought to be outside seismic regions but where careful research had yielded evidence of past earthquakes which had not been widely documented. The value of aerial photographs in reservoir exploration was stressed particularly when searching for possible defects in reservoir rims. In such circumstances, the use of panchromatic film, I.R. imagery or line scanning techniques had special value. It was generally agreed that a geologist had a reasonable opportunity to request methods of air photography if a real need could be demonstrated. The anomaly which arose when a formation which was used as an aquifer in a particular region was simultaneously being explored for the construction of an impounding reservoir within its outcrop was high-lighted. There was some suggestion that parts of the Chalk in the U.K. might be well-suited for reservoir construction following these lines of argument. Particular problems arose in the case of old dams founded on uncertain geological foundations which could give rise to problems with time and an example of reservoir leakage below an embankment in the southern uplands of Scotland was used to illustrate this point. Bearing in mind that the field visit would