Thule black sand province and regional geology - review and summary of data and work

The Thule black sand province in North-West Greenland (76°–78°N) composes a coastline several hundred kilometres long. Both ilmenite-rich and magnetite-rich sands occur with the former appearing to be the most extensive.

Elevated ilmenite concentrations (up to 60 wt% ilmenite with an average of 37%) are recorded on both active and uplifted beaches. The main source of the ilmenite sands is a regional Precambrian basaltic sill and dyke complex that intrudes the Precambrian basement. The sills have unusually high titanium content; up to 5.25 wt.% in whole-rock analysis. As a regional magmatic suite the rocks represent some of the most titanium-rich basalts in Greenland.

The chemical composition of the ilmenite is between 46–48 wt.% TiO2 with moderate high vanadium content. CaO and MgO are consistently low; with average value of 0.1 wt.% for CaO and 0.67 wt.% for MgO. Uranium and and thorium content are also low. Earlier commercial studies on the black sand deposits have concluded that a high TiO2 content slag of a Moriusaq ilmenite concentrate could be produced because the level of other oxides is lower than most ilmenite smelted.

This report reviews the regional geology and known mineralisations in the area,especially the black sand deposits at Moriusaq. The exploration and research history is outlined and a list of the most important references is given as well as a list of sample material archived at GEUS.