Evolution of ore forming fluids at the Jonsfjorden gold prospect, Svalbard
Master project of Eirik Valdar
Hovedinnhold
Title
Evolution of ore forming fluids at the Jonsfjorden gold prospect, Svalbard
Supervisors
Sabina Strmic Palinkas (UiT/UiB), Rolf Birger Pedersen (UiB), Harald Hansen (UiT)
Project description
A gold-bearing prospect area located on the southern side of St.Jonsfjorden have become of renewed interest with rising metal prices. In September of 2022 Store Norske Spitsbergen Kullkompani organized a field sampling campaign to the copper and gold bearing localities at Copper Camp and Holmslettfjell in St. Jonsfjorden. Detailed sampling was undergone to obtain understanding of the localities. The following questions will be answered to get comprehensive knowledge on the ore forming and developing processes of the prospect: 1) How did ore-forming fluids evolve in the P-T-X space?; 2) What is the main source of metal-bearing fluids? and 3) What are the sources of metals and metalloids, including Au, Cu and As, and sulfur?
Gold-bearing mineralization in St.Jonsfjorden occurs as forms of epigenetic hydrothermal veins and as disseminations in carbonate-rich lithologies. Gold is associated with two main types of hydrothermal mineral assemblages: 1) assemblages composed predominantly of chalcopyrite, pyrite, quartz and minor amounts of carbonates; and 2) assemblages composed predominantly of arsenopyrite, pyrite, quartz and abundant carbonates. The chalcopyrite-rich assemblages have been found at the Copper Camp locality. The form in which gold occurs in this type of mineral assemblages is still unclear. The arsenopyrite-rich assemblages are particularly well exposed at the Holmslettfjella locality. In this type of assemblages, gold occurs within crystal lattice of arsenopyrite. A spatial positive correlation of arsenic and gold has been recognized in overbank sediments at several other localities in Svalbard. Most of the previous work done on the St. Jonsfjorden gold prospect has been performed by the company Store Norske Gull (SNG). In the period between 2008 and 2010 SNG drilled 12 exploration drill holes at the Holmslettfjell locality.
