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LITHOLOG]' AND PYP.ITE CONTENT CHARACTERIZATION • BETWEEN THE BOTTOM OF THE AMEPIDMENT 6 PIT AND THE CARLTON TUNNEL by Henry Unger February, 1994 Based on the available data, the material between the bottom of the design pit and the Carlton tunnel is very similar to the unoxidized near-surface material, and there is little chance for major high-sulfide bodies at depth. The deep exposures contain no more sulfide than unoxidized near-surface rocks, averaging about 29 sulfide to 7800 fc. elevation. The gross lithologies exposed at depth are also typical of the district units. The only significant change with depth is the loss of surface oxidation. The available geologic data for the area between the bottom of the Amendment 6 design pit and the Carlton tunnel includes: A total of 12 deep (>1000 ft., max 2396 ft.) drill holes, * Wide spaced geologic mapping and sampling of the historic Cresson mine, •~ Detailed mapping of the Cresson Lateral of Che Carlton Tunnel, and ~• Published literature and historical mine data. A summary of attached illustrations is given below: Illustration Data Cresson E-W Cross Section Deep drill data Plan View of Deep Drilling Deep drill data Two Cresson Lateral geology maps Carlton level mapping Location of Cresson Lateral Page 153 Lindgren ~ Ransome District vein character • Based on the following data, there is little risk of major increases in sulfide content at depth: - Pyrite histograms on the cross section are only locally above 28, and almost all of the deepest core contains from 1 to 2$ pyrite. Out of 3260 records, there are no intervals in the >88 pyrite categor}' and only 5 intervals in the 4-89 pyrite categor}'~ - The detailed geologic mapping of the Cresson lateral on the Carlton level (7000 ft. elevation) shows onl}' minor zones of elevated disseminated p}rite and pyrite stringers. - The generalized geology and sample data from the historic Cresson mine does not noCe any major sulfidic zones. While overall pyrite contents are not noted, major sulFide bodies would undoubtedly have been mapped. - Tliere are no references in the published literature or tl~e available mine documents to any major semimassive or massive sulfide bodies. The zones ~aich the highest sulfide content are narrow veins (generally «1 fc iri width) containing <109 sulfide. - Detailed geologic descriptions from the Carlton tunnel level, the deepest mapping in the district, are typical of unoxidized near- surface exposures. The published data also note t}'pical district lithologies ac depth. - And, finally- the empirical evidence. There is very little High sulfide material on the waste dumps from the underground mines in the area. Plus. I mn not aware of any massive or semimassive sulfide waste ac all. •