Metallogeny of the North Atlantic Craton in Greenland

Abstract

The North Atlantic Craton (NAC) extends along the coasts of southern Greenland. At its northern and southern margins, Archaean rocks are overprinted by Palaeoproterozoic orogeny or overlain by younger rocks. Typical granite-greenstone and granite-gneiss complexes represent the entire Archaean, with a hiatus from ∼3.55–3.20 Ga. In the granulite- and amphibolite-facies terranes, the metallogeny comprises hypozonal orogenic gold and Ni-PGE-Cr-Ti-V in mafic-ultramafic magmatic systems. Gold occurrences are widespread around and south of the capital, Nuuk. Nickel mineralization in the Maniitsoq Ni project is hosted in the Norite belt; Cr and PGE in Qeqertarssuatsiaq, and Ti-V in Sinarsuk in the Fiskenæsset complex. The lower-grade metamorphic Isua greenstone belt hosts the >1000 Mt Isua iron deposit in an Eoarchaean banded iron formation. Major Neoarchaean shear zones host mesozonal orogenic gold mineralization over considerable strike length in South-West Greenland. The current metallogenic model of the NAC is based on low-resolution data and variable geological understanding, and prospecting has been the main exploration method. In order to generate a robust understanding of the metal endowment, it is necessary to apply an integrated and collective approach. The NAC is similar to other well-endowed Archaean terranes but is underexplored, and is therefore likely to host numerous targets for greenfields exploration.

Re-evaluating ambiguous age relationships in Archean cratons: Implications for the origin of ultramafic-mafic complexes in the Lewisian Gneiss Complex

“…This underlines the possibility that high-grade metamorphic events, such as the Badcallian in the LGC, may obscure temporally and/or petrogenetically distinct magmatic events, as may be typical in marginal cratonic regions (such as the LGC, within the wider NAC). This supports the study of Kolb et al (2015), who identified multiple episodes of Archean ultramafic-mafic magmatism in the Greenlandic portion of the NAC.…”

Metallogeny of Greenland

“…The main orthomagmatic mineral systems formed at ca. 2970-2950 Ma and are relatively old compared to their counterparts in Australia and Canada (Cawood and Hawkesworth, 2015;Kolb et al, 2015). Only small VHMS occurrences are known, probably because of the weak preservation potential in the deeper crust (Fig.…”

“…Most of the Archean rocks are at amphibolite facies or granulite facies metamorphic grade. Middle to deep crustal processes define the preservation potential and the mineral systems for possible ore deposits and mainly three types are known (Kolb et al, 2015): (1) orthomagmatic deposits with mineralization of Cr-Ti-V-Ni-PGE-Au;…”

Greenland mineral exploration history

“…More recent reviews focus on specific metallogenic provinces in Greenland that are systematically related to a variety of geological terrains: Steenfeldt et al (1997) on South Greenland and more recently by Stendal et al (2005), and Kolb et al (2015Kolb et al ( , 2016Kolb et al ( , 2017 covering most of the geological terrains in Greenland.…”