Issue link: http://resourceworld.uberflip.com/i/261649
16 www.resourceworld.com F E B R U A R Y / M A R C H 2 0 1 4 The practicality and the ease of explor- ing the target need also be considered. An academic type of exploration with unre- alistic targets and large expenses are to be avoided at all costs. That was the case of a company incurring large expenses while deep drilling a Canadian astrobleme (rem- nant of a meteor impact) site in search of the next Sudbury. It failed. Chance plays a major role in mineral exploration. There are companies that explored for diamonds; they drilled geo - physical anomalies but found only coal or graphite. As a general rule, an inves- tor should keep tabs on companies that explore promising geological settings and have the means to reach their explora- tion goals. The investor should swiftly react by buying into them as soon as they announce a discovery. The investor might then sell at least part of their position at a profit once the wave of enthusiasm starts wearing off. EXPLORATION METHODS Chip and channel rock samples are better at representing the grade and type of mineral- ization than grab samples which are selected samples. High assays coming from grab sam- ples should not be trusted as representing the grade of a possible underlying mineral deposit. Soil sampling and stream sediment sam- pling are geochemical survey methods that could be used to identify an anomalous area and the association of metals of interest. Various geophysical methods are used to delineate anomalies that do not necessarily represent a mineralized zone, but variations in the physical properties of the underlying rocks. Co-incident geophysical and geo - chemical anomalies (a good sign) are usually drilled if they are located in the right geo- logical setting for the identified anomalous concentrations of metals. Bulk sampling methods are employed in situations where there is a high variability of metal content (the nugget effect). Individual assays cannot be trusted to be extrapolated and used in resource estimations. DRILLING, GRADES AND MINING FACTORS The ultimate ground truthing tool is the drill bit and diamond drilling rules as the undisputed king of mineral exploration. One of the most common challenges faced by investors trying to understand the significance of a drill intersection is the way juniors report them. It is common practice to report a large mineralized inter - val at a lower grade but which contains a higher grade interval. Is that grade-smear- ing or a legitimate presentation? What the investor needs to know is the grade of each interval. A Corebox tool (corebox. net) allows us to do that calculation. In the case of a structurally-controlled continuous tabular deposit, it might not make sense to mine anything else but the higher grade interval contained within the larger interval. In other cases, the grade of the wider low-grade interval could be taken into consideration as being above the economic cut-off grade if a bulk min - ing operation is feasible. A savvy investor would have to figure out the possible type of mining and mining