"The exploration of Greenland, especially north-east Greenland, was a hot topic 120, 130 years ago," says Thomas Find Kokfelt, senior researcher at the Geological Survey of Denmark and Greenland (GEUS). Various minerals were discovered and mines began to pop up.

In 1850, the mineral cryolite, the "ice that never melts", due to its extremely high melting point, was found in south-west Greenland. Settlers started mining cryolite after they learned its use in making bicarbonate of soda. During World War Two, the Ivittuut mine supplied the Allied forces with cryolite – an important mineral in the production of aluminium used in planes.

Geologic mapping in Greenland began in earnest after World War Two. After 20 years of trekking along the coastline, it became clear that mapping was a humungous undertaking. "If you divide all of the ice-free areas of Greenland, you can probably fit 200 map sheets of a one to 100,000 scale," Find Kokfelt says. When the geologists did the maths, they realised it would take 200 years to finish mapping at their current rate. They pivoted to a coarser resolution effort and finished the initial geologic maps of Greenland in the early 2000s.

Since then, the GEUS has been refining the maps, zooming in to a finer resolution. To date, geologists have completed 55 maps at a more detailed scale. They have also delved into under-ice mapping efforts. Recently, Find Kokfelt teamed up with geophysicists to create a map of geologic provinces, large-scale regions with distinctive characteristics, beneath the ice sheet. These provinces also hint at what minerals might be present. But like the initial geologic maps, Find Kokfelt is quick to mention the province maps be further refined with more data.