DUV Target Zone
The DUV Target Zone is a major center of porphyry style alteration in the Emigrant District and is located in the East Fork of Emigrant Creek. Mineralization in DUV Target Area is associated with hydrothermal breccia, strong silicification, and quartz-sericite-pyrite alteration all of which are related to development of the irregularly-shaped DUV breccia pipe. Mineralization also appears to be related to the later-stage quartz monzonite porphyry and quartz monzonite dykes intruded into the dacite porphyry of the Emigrant stock. Gold mineralization is associated with the breccia pipe as well as with later-stage quartz monzonite and quartz monzonite porphyry dykes.
Drilling and mapping by Pegasus in 1991 and 1992 indicate that the Emigrant quartz monzonite stock in the DUV area probably extends at depth in the subsurface from the East Fork of Emigrant Creek to the north of the Allison Tunnel area and probably as far north as the Peter Pear Target Areas described below. The better grades of gold mineralization, including significant drill intercepts > 0.1 oz gold/ton in several holes, occurs at the intersection between the breccia pipe and a relatively flat-lying to moderately south dipping zone between elevations of 8,100 and 8,800 feet. The relatively flat-lying mineralized zone may represent a boiling zone within and adjacent to the breccia pipe which appears to be steeply dipping. Mineralizing fluids appear to have come up through the breccia pipe and followed the contact between dacite porphyry and a less porous welded tuff. The projected contact of the dacite porphyry with the overlying welded tuff appears to be particularly favorable for gold deposition. The mineralized copper-gold zone, so far as known, ranges to as much as 500 meters (700 feet) in thickness with a horizontal expression approximating 750 meters x 800 meters (800 feet by 1,200 feet). Within this zone, gold mineralization with associated copper, with a tenor of greater 0.03 opt occurs in drill intercepts as much as 132 meters(434 feet) thick.
In 1971, Duval Corporation, Inc. contracted with Geoterrex, Ltd. Inc. to conduct Induced Polarization geophysical surveys along two crossing lines, each more than 1.5 miles long and centered on the junction of Emigrant Creek / East Emigrant Creek center of hydrothermal alteration. The locations of the geophysical lines are shown on Figure 26 (main body of report). In 2007, NewEdge Gold contracted with Carlson Geophysics of Missoula Montana to reinterpret the historical Induced Polarization surveys and refine the Induced Polarization / Resistivity data that was collected in 1971 using more advanced computer techniques than were available at the time the data were collected. The reinterpretation resulted in extremely high chargeability anomalies that likely indicate sulfides and associated mineralization in the survey area and are areas to be focused on for mineral exploration. A southwest-northeast oriented Line (Line #1) shows a very high chargeability anomaly over the upper East Fork of Emigrant Creek in the vicinity of the DUV and St. Julian Target Areas. A north-south oriented Line (Line #2) also shows two very high chargeability anomalies, one is located east of Emigrant Creek and is approximately centered between the Allison Tunnel and Great Eastern breccia pipes. Thus the surveys identify known and new target areas in both the Emigrant creek and East Fork of Emigrant Creek areas.