Resource Base:- This is the totality of an element as it occurs in its many chemical and physical states within the earth’s crust. For example, the resource base for the metal copper will include all occurrences as native copper; oxides and sulphides of copper in magmatic, sedimentary and metamorphic environments.
Mineral Endowment in Exploration
If now we restrict our copper resource to only sulphides and oxides for which the grade is known (t*); the minimum cut off grade (q*) is known (q* > t*) and the depth of occurrence (h* meters) is also known. Then the total amount of copper in these occurrences is referred to as mineral endowment and could be produced economically at e*.
Potential Supply in Exploration
The total amount of copper in all these occurrences that could be discovered and produced economically at e* constitutes the potential supply.
Reserves of Copper
The amount of copper estimated to be present in all known occurrences producible at ‘eo’ is known as the reserves of copper. These terms are illustrated schematically in.
Better methods for estimating the magnitude of potential mineral resources are needed to provide the knowledge that should guide the design of many key public policies. The mineral resource potential of an area is a measure of the likelihood of occurrence of valuable mineral or minerals that may become valuable within the foreseeable future.
This likelihood of occurrence is not a measure of the resources themselves and thus cannot be evaluated by reference to the two-dimensional McKelvey Box Figure 4, which categorizes undiscovered resources, the potential, as speculative or hypothetical. The likelihood of occurrence can only be judged by integrating many diverse factors.
Some of these factors can be measured while some are cryptic and indefinably esoteric, depending in part on the specific experience and knowledge of the individual making the judgment. Consequently, for well-informed and accurate analysis of the resource potential of any locality, we necessarily have to rely on the judgment of a knowledgeable economic geologist who mentally integrates a wide range of geologic elements in ways that numerical methods cannot yet accomplish.
His approach generally involves comparing available geologic, geochemical and geophysical data with those from known and developed ore deposits. The primary objective is to identify geologic environments favorable for the occurrence of mineral resources in the area under examination.
Ore deposit models applied meticulously help to flush our incomplete descriptive frameworks and establish whether the basic conditions of ore formation are met. In any area, a large number of ore genetic models must be considered, some selected for closer examination if geologic factors are favorable, some to be rejected if the factors are unfavorable.