ABSTRACT

Today, most potential orebodies are explored using diamond core drilling. The small diameter core collected from each hole provides a continuous ‘line’ of geologic information. Each of the recovered cores is studied in detail and the contained information recorded. The process is called ‘logging’. Each ‘line’ is subsequently subdivided into a series of segments representing a particular rock type, structural feature, type of mineralization, grade, etc. By drilling a pattern of such holes, a series of similarly segmented lines are located in space. Using this information, together with a knowledge of the geologic setting and other factors, the mining geologist proceeds to construct a 3-dimensional representation of the mineralized body. The objective is to quantify, as best possible, the size, shape and distribution of the observable geologic features. The distribution of ore grades are correlated to lithology, alteration, structure, etc. The result is a mineral inventory or geological reserve. At this point in the evaluation process, economics have not been introduced so that terms such as ‘ore’ or ‘ore reserve’ are not involved.