7. Exploration

Abstract

7.1. Introduction This chapter on the exploration for and of clay deposits for man's benefit covers a range of topics. It is essential to comprehend the difference between a clay deposit and a reserve. In order for an exploration programme to provide the information required in an efficient manner, the data collection needs careful planning. This process is best carried out in stages, with the plans for later stages depending on the results of earlier stages. The critical importance of the exploration being led by a qualified geologist who has relevant experience in the type of deposit under study is emphasized. Methods of non-intrusive investigation, used before significant expenditure on field work, are summarized, followed by a review of intrusive methods of investigation. This coverage is brief, not repeating the coverage of exploration techniques covered in most textbooks and Standards on field investigations, for instance Clayton et al (1988) and BS 5930:1999. The use of geophysical methods to enhance the drilling programme is discussed, again emphasizing the need for competent persons, and sampling programmes and sample types are reviewed. The importance of iterative reporting of the phases of the investigation is threaded through the presentation, as it would be in the development of the assessment of the clay deposit. The purpose of geological exploration is progressively to build a three-dimensional model of the ground, including the relevant location and characteristics of the mineral strata and the groundwater appropriate to the extraction of the clay mineral. In the context of mineral