Geochemical exploration for gold in temperate, arid, semi-arid, and rain-forest terrains

Abstract

In this chapter we examine how geochemical techniques can be utilized in the exploration for different types of gold mineralization, the specific signatures of which must be identified in the various sampling media (rock, soil, etc.) used for exploration. The geochemical signature of gold mineralization depends upon several parameters, particularly the style of mineralization in question and the physico-chemical characteristics of the supergene environment. Consequently, different topographic and climatic environments will be considered, where the transposition of the characteristics of the primary mineralization to the surface sampling media may vary. This will be illustrated using a range of examples, emphasizing the procedures used as well as the results obtained. Two main components of the geochemical signature will be distinguished: Au and the pathfinder elements. By using the latter, an indication is obtained of the lithology and mineralizing processes, factors which are especially useful in terrains where outcrop is poor. However, problems specific to explorations in till-covered areas are considered by Coker and Shilts in Chapter 11.