Agreement over the form of a paper will not necessarily be universal. The alternative methodology and table proposed by Morton and Sayer would tend to suggest that more is known about the geology and engineering geology of Singapore than is actually the case. Single ‘typical’ values presented to summarize soil properties are almost inevitably misleading. Singapore geology typifies the problem. Furthermore, Morton and Sayer present an example which appears to faithfully follow the system adopted during the Mass Rapid Transit site investigation, which, in particular with respect to weathering grades, has caused a good deal of (at least initial) confusion. The form of a classification does, of course, depend upon the purpose to which it is to be put. One use may be to assess conditions for foundation purposes. In such a case, the classification presented by Morton and Sayer would probably be too coarse. There are, however, other uses.
The suggestion that a deposit can be classified on the basis of origin, process of accumulation, and geomorphology is, of course, reasonable. However, it is difficult to agree to this being automatically taken to the further stage of accepting that general quantitative characteristics apply to the deposits. One fact which is perhaps becoming evident in Singapore is that variability is actually a characteristic of many materials.
The quantitative information presented in the paper for the Marine Clay is for perhaps the most intensively investigated of deposits in Singapore. The great variation in properties have been dealt with by Tan (1983)
- © The Geological Society 1985