Locally high concentrations of gold in quartz veins and surrounding alteration zone have been found on the island of Qilanngarssuit, west of Buksefjorden, southern West Greenland. Soil samples around Buksefjorden record up to 300 ppb gold, suggesting a potential for further exploration in the surrounding area.
During the GEUS field season in summer 2008, a research team including 4 geologists visited the island of Qilanngarssuit in order to study the potential for hydrothermal gold mineralisation.
A narrow quartz vein system was mapped out along a syncline formed by amphibolite and paragneiss (Malene supracrustal rocks) in an orthogneiss basement (Amitsoq gneiss). The veins are 10-20 cm wide and locally several parallel veins form a laminated texture. The veins are parallel to the main foliation and can be followed along strike over several hundred meters, whereas, locally, sigmoidal extension veins crosscut the foliation. In places, they are sheared off or boudinaged due to flexural slip folding of the regional syncline structure. Gold analyses of chip samples of 6 veins yielded in general relatively low values around 10-40 ppb of gold. But one quartz vein sample sticks out with a gold content of 769 ppb. Further samples are being analysed.
The veins are surrounded by approximately 6 m wide alteration zones containing biotite, quartz, garnet, sillimanite, tourmaline, pyrrhotite, pyrite, and chalcopyrite. These alteration zones are enriched in gold compared to the unaltered wall rocks with values between 20 ppb and 50 ppb. One sample from the proximal alteration zone contains 672 ppb gold.
Although the gold values are rather low, soil samples from the region around Buksefjorden record up to 300 ppb gold, suggesting a potential for further exploration in a larger area around Qilanngarssuit and Buksefjorden. The recently found anomalous gold zones are situated along the south-western strike extent of the known Godthåbsfjord gold occurrences (i.e.; Storø, Qussuk) and should be noticed in that regard. GEUS is currently undertaking more research work and more geochemical analyses.
Further information:
Meet the scientist from GEUS at booth 417 at Prospectors and Developers Association of Canada - PDAC in Toronto from 1-4th March 2009
Or contact them in Copenhagen, Denmark
Jochen Kolb, GEUS
Phone: +45 38142212
E-mail: jkol@geus.dk
Denis Martin Schlatter, GEUS
Phone: +45 38142264
E-mail: dms@geus.dk