Fact Sheet 17, 2008

Mineral potential of the Thule Basin

The intracratonic Thule Basin straddles northern Baffin Bay and has its largest part submerged. The most extensive onshore exposures are on the Greenland side. The basin is one of several Proterozoic depocentres on the northern rim of the North American craton with comparable development histories: thick sandstone and basalt units in lower levels, often with red beds, are succeeded by carbonate/shale-dominated sequences. Two of these basins are the Athabasca Basin of northern Saskatchewan and the Borden Basin of northern Baffin Island, both known for their economic mineralisation, U and Pb-Zn, respectively.

Geology and mineralisation

The Thule Basin was mapped in the 1970s. It has seen little commercial exploration but in Greenland intermittent economic reconnaissance was performed 2001–07 by GEUS. The bedrock of the Thule region is dominated by two Precambrian provinces: a high-grade Archaean–Palaeoproterozoic crystalline shield overlain by the unmetamorphosed Mesoproterozoic–?Neoproterozoic strata of the Thule Basin (Thule Supergroup). The profound unconformity between these two provinces is well preserved through the region. To the north, the Super-group is disconformably overlain by the Lower Palaeozoic Franklinian Basin. The Thule Supergroup is a 6–8 km thick multicoloured, continental to shallow marine se quence with one main interval of terrestrial basaltic rocks. Basic sills are common at several levels. The strata are little deformed occurring as shallow-dipping packages in fault blocks.