1. Orogenic gold mineralisation in the Archean North Atlantic craton, southern West and South-West Greenland
Jochen Kolb1, Denis M. Schlatter1, Annika Dziggel2, Alexander F.M. Kisters3
¹Department of Petrology and Economic Geology, Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
2Institute of Mineralogy and Economic Geology, RWTH Aachen University, Wüllnerstr. 2, Aachen, Germany
3Department of Earth Sciences, Stellenbosch University, Matieland 7602, South Africa

2. Mineralizing system of orogenic gold deposits
SOURCE ROCK
CONDUIT
Fluid/wallrock
reactions
Au deposition
increasing intensitiy of alteration
Dispersion
Diffusion
hydrothermal alteration
Ridley et al. 1996
Main devolatilization
440 – 520°C
Philipps and Powell 2010
Groves et al. 1993

3. Gold production vs. gold ages
Goldfarb et al. 2001
North Atlantic craton

4. Schematic geologocal map of Greenland

5. Geological map of South-West Greenland
Paamiut gold province
Tartoq gold province

6. Characteristics of gold mineralization
Paamiut gold province
5 occurrences; 40 km strike
Auriferous quartz veins in higher-order structures
Au-only + As, W, Mo, Bi
Ore mineralogy: Po-Apy-Ccp
Hydrothermal alteration mineralogy
Proximal Hbl
Distal Qtz-Hbl/Oam-Bt-Tur-Ank ± Grt, Ms, Cal
Sulfide-poor (< 5 vol.%)
Tartoq gold province
≥ 3 occurrences; 40 km strike
Auriferous quartz veins in higher-order structures
Au-only + As, Ag, W, Sb, Bi
Ore mineralogy: Apy-Ccp-Py
Hydrothermal alteration mineralogy
Qtz-Ms-Chl-Ank
Sulfide-poor (< 5 vol.%); except BIF

7. The Paamiut gold province: structure
Metamorphic dates
2850 – 2830 Ma: Paamiut orogeny
2760 – 2740 Ma: Tasiusarsuaq orogeny

8. The Tartoq gold province: structure
±Au
±Au Au Au
Metamorphic dates
2850 – 2830 Ma: Paamiut orogeny
2760 – 2740 Ma: Tasiusarsuaq orogeny

9. Geological map of southern West Greenland
Sermilik prospect
Bjørnesund occurrence
Ca Ma

10. Characteristics of gold mineralization
Sermilik gold prospect
≥ 2 locations; 4 km strike
Ca Ma
Auriferous quartz veins in folds and shear zones
Gold-only + Ag, As
Ore mineralogy: Po-Ccp-Py-Ilm-Mag
Hydrothermal alteration mineralogy
Qtz-Grt-Bt-Kfs (660°C, kbar)
Sulfide-poor (< 5 vol.%)

11. Tectonic model for the Sermilik prospect: Tasiusarsuaq orogeny

12. Geological map of southern West Greenland

13. Characteristics of gold mineralization
Godthåbsfjord gold province
Tasiusarsuaq gold province
≥ 5 prospects; 110 km strike
2985 Ma, 2715 Ma, 2630 Ma
Gold-quartz±carbonate veins
Ore mineralogy: Po-Ccp-Apy-Py-Ilm-Mag
Hydrothermal alteration mineralogy
Inner Qtz-Hbl ± Bt
Proximal Qtz-Grt-Bt-Hbl-Sil ( °C, 4-6 kbar)
Distal Bt ± Grt
Sulfide-poor (< 5 vol.%)
≥ 7 locations; terrane-scale
Ca Ma
Quartz veins ± Au
Ore mineralogy: Po-Ccp-Py-Ilm-Mag
Hydrothermal alteration mineralogy
Inner Qtz-Hbl ± Bt, Ep, Rt
Proximal Qtz-Grt-Bt-Hbl ± Ms (650°C, kbar)
Distal Bt ± Grt
Sulfide-poor (< 5 vol.%)

14. Structure of the Godthåbsfjord and Tasiusarsuaq gold provinces

15. Model for 2670-2580 Ma orogenic gold

16. Conclusions Several stages of orogenic gold mineralization
ca Ma Isukasia orogeny
2850 – 2830 Ma Paamiut orogeny
2800 – 2740 Ma Tasiusarsuaq orogeny
2720 – 2700 Ma Tre Brødre orogeny
2670 – 2580 Ma Kapisilik orogeny
Hypozonal orogenic gold
Tasiusarsuaq gold province: single-stage – no potential
Godthåbsfjord gold province: multi-stage (?) – small deposits
Mesozonal orogenic gold
Paamiut gold province – not explored, good potential
Tartoq gold province – not explored, good potential