Unnamed (near Ester Dome)

Prospect, Active

Commodities and mineralogy

Main commodities Au
Other commodities As; Sb
Ore minerals arsenopyrite; gold; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale FB
Quadrangle map, 1:63,360-scale D-3
Latitude 64.8897
Longitude -148.0675
Nearby scientific data Find additional scientific data near this location
Location and accuracy Although several other older, small prospects (FB005 to FB011) are peripheral to or within the large block of claims of this prospect, it covers an area trending north-northwest about 5,900 feet long by 590 to 1,640 feet wide that was drilled in 2011. The coordinates are near the center of the area about a mile north-northwest of the top of Ester Dome in the north half of section 25, T. 1 N., R. 3 W. The location is accurate.

Geologic setting

Geologic description

Since the early 1900s , the Ester Dome area has been known for scattered gold-quartz veins with stibnite and arsenopyrite, some of which have been mined. Much of the area has been claimed and reclaimed several times, including the area surrounding this prospect on the north side of Ester Dome. In 2009, Miranda Gold Corporation (2009) leased a large block of claims from Range Minerals Inc. on the north side of Ester Dome and began exploration. The block included several older, small prospects (FB005-FB011), mostly gold-quartz veins, but Miranda's work was m mainly to test the area for large, bulk-minable, intrusion-related gold deposits. By 2011, Miranda had defined a north-northwest-trending area, geochemically anomalous in gold, about 5,900 feet long ft long by 590 to 1,640 feet wide. Miranda and their partner Agnico-Eagle (USA) drilled 6 holes on the anomaly in 2011 (Miranda Gold Corporation, 2012); four of the holes cut mineralization with more than 0.01 ounce of gold per ton. The four mineralized holes had 17 intercepts 0.9 to 6.1 meters wide with more than 0.5 gram of gold per tonne. Notable intercepts were 0.9 meters with 0.922 gram of gold per tonne, 2.3 meters with 0.723 gram of gold per tonne, 2.6 meters with 0.831 gram of gold per tonne, and 6.1 meters with 0.603 gram of gold per tonne, and 1.5 meters with 1.005 gram of gold per tonne. The mineralization is related to quartz sulfide veinlets and intense fracturing accompanied by iron oxides and selvages with quartz-sericite-pyrite alteration. In 1998, Placer Dome drilled similar mineralization (FB011) near the southern border of Miranda's geochemical anomaly.
The rocks in the area are part of the Fairbanks Schist composed of quartz-muscovite schist, quartzite, and chlorite-quartz schist that are cut by thrust faults (Newberry and others, 1996). The geochemical anomaly defined and drilled by Miranda is associated with a cluster of granitic bodies that intrude the metamorphic rocks (Miranda Gold Corp., 2011).
Geologic map unit (-148.069933016823, 64.8892624091592)
Mineral deposit model Gold-quartz veins; intrusion-related, bulk-tonnage gold deposit (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Probably about 90 Ma based on similarities to many gold deposits in the Fairbanks District.
Alteration of deposit The mineralization is related to quartz sulfide veinlets and to intense fracturing accompanied by iron oxides and selvages with quartz-sericite-pyrite alteration.

Production and reserves

Workings or exploration In 2009. Miranda Gold Corporation (2009) leased a large block of claims from Range Minerals Inc. on the north side of Ester Dome 11, and began exploration. By 2011, Miranda had defined a north-northwest-trending area, geochemically anomalous in gold, about 5,900 feet long by 590 to 1,640 feet wide, within their block of claims. Miranda and their partner Agnico-Eagle (USA) drilled 6 holes on the anomaly in 2011 (Miranda Gold Corporation, 2012).
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Miranda Gold Corp., 2009, Miranda Gold acquires district-scale gold play in Alaska: http://www.mirandagold.com/s/NewsReleases.asp?ReportID=369974&_Type=News-Releases&_Title=Miranda-Gold-Acquires-District-Scale-Gold-Play-in-Alaska (News release, Nov 2, 2009).
Miranda Gold Corporation, 2011, Drilling begins on Miranda's Ester Dome project, Alaska: http://www.mirandagold.com/s/NewsReleases.asp?ReportID=479397&_Type=News-Releases&_Title=Drilling-Begins-on-Mirandas-Ester-Dome-Project-Alaska (News release, September 15, 2011).
Miranda Gold Corporation, 2012, Miranda Gold reports 2011 drill results from Ester Dome project: http://www.mirandagold.com/s/NewsReleases.asp?ReportID=502120&_Type=News-Releases&_Title=Miranda-Gold-Reports-2011-Drill-Results-From-Ester-Dome-Project (News release, January 17, 2012).
Reporters D.J. Grybeck (Contractor, USGS)
Last report date 4/1/2012