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rr"PITASCA: <br /> Denver, Inc. <br /> 2.0 SAMPLE SELECTION <br /> 2.1 WASTE-ROCK CLASSIFICATION <br /> Geologic logging and geochemical sampling are conducted by CC&V as part of the ongoing <br /> exploration drilling program. In addition to precious metal assays for evaluating ore grade, the <br /> geochemical sampling also includes periodic measurements of total sulfur and total carbon <br /> concentrations in the rock samples using combustion-infrared spectrophotometry (by LECO'm or <br /> a similar brand of combustion furnace,and commonly referred to as LECOTm analyses).The results <br /> of the logging and sampling are maintained in a Project database,which was used to identify and <br /> quantify the types of waste rock associated with the Project and to develop the testing plan <br /> described in the following sections.These data were also used to develop a representation of the <br /> ranges of chemical composition—with respect to sulfur and carbon, which are proxy <br /> measurements for the acid-generating potential (AGP) and acid-neutralizing potential (ANP), <br /> respectively—for each rock type that is part of the overall Project. This representation was used <br /> to evaluate the representativeness of the samples selected for the WRCS. <br /> The geology and LECOM results for all waste-rock intervals were extracted from the CC&V <br /> database and included approximately 10,000 samples. Each of the 36 distinct geologic <br /> classification codes used by CC&V was then assigned to one of six rock-type groups, as listed in <br /> Table 2-1. The results were used to estimate the relative abundance of each classification code <br /> and rock-type group, as shown in Figure 2-1. The rock-type groups selected for use in the WRCS <br /> are as follows: <br /> 1. Breccia (58%), <br /> 2. Porphyritic phonolite (32%), <br /> 3. Aphanitic phonolite (5%), <br /> 4. Other intrusive (3%), <br /> 5. Lamprophyre (2%), and <br /> 6. Vein/other(less than 1%). <br /> 4 <br />