Potential for geologic resources in Greenland

Greenland

Greenland reaches from the Northernmost exposed land on Earth bordering on the Arctic Ocean to Cape Farewell in the North Atlantic at latitudes similar to Southern Norway. The surface of Greenland is dominated by the Inland Ice and glacial deposit formed during the retreat of the ice since the last Ice age. The Inland Ice covers ca. 80 % of Greenland surface and only a fringe of land, a few hundreds of kilometers in width, is exposed along the coast. Still the ice-free land area is 410.000 km2, which is greater than the area of Germany. It is often speculated that the present warming of the Arctic region has a dramatic effect on the amount of exposed land, and thus on the potential for identifying economic mineral deposits. However, the increase in exposure is minimal, and most probably, the exposed area of Greenland will not increase significantly during this century. The population of Greenland is ca. 56.000. Most live on the southwest coast, and are increasingly concentrating in the larger cities, of which Nuuk, the capital, is the largest with 16,000 inhabitants.

Geological framework
The National Geological Survey of Denmark and Greenland (GEUS) have mapped all of Greenland at least to the detail of 1:500.000, and many areas to greater detail. 

Most of Greenland is covered by airborne geophysical surveys, including gravity and magnetic mapping, and large areas have been mapped geochemically by airborne gamma spectroscopy and stream sediment geochemistry.

Greenland is thus well characterized for its general geology, and it is possible to focus exploration for economic mineral depots to restricted areas with greater potential for specific types of mineralization or petroleum.

 

All of Greenland is underlain by Precambrian basement dominated by gneisses mainly derived from magmatic precursors. Greenland can be divided into geologic provinces based on the age of formation and the age and style of tectonic overprinting of the basement, and on the presence of magmatic and sedimentary cover.

The present outline of Greenland is defined by the breaking up of the supercontinent Pangea. The break-up started during the Jurassic period ca. 175 million years ago, and lead to the separation of Greenland from Canada and Europe during the Cretaceous and Paleogene ca. 90-50 million years ago. The separation of Greenland from Labrador and Baffin Island that is now defined by the Labrador Sea and the Baffin Bay started during the Cretaceous ca. 90 million years ago, and caused generation of new ocean floor in the Labrador Sea.

Slightly later the rifting jumped to the present East coast, and separated Greenland from Europe. This relationship between Greenland and Canada and Europe means that large geologic structures are contiguous between Canada and Greenland, and similarly between East Greenland and the Baltic shield in Europe.

The mineral potential can therefore to some extent be extrapolated form one part of the broken continent to the other. This is the case for a large zinc and lead mineralization province that can be traced along the North coast of Greenland and into the North Canadian Islands: Two mines, the, Nanisivik and Polaris have been mined in Canada, and a very large zinc – lead deposit has been documented in Citronen Fiord on the Greenland coast to the Arctic Ocean. Likewise, the Voisey's Bay nickel mine in Labrador, is part of a geologic structure that can be traced into Greenland, and have sparked hope of large nickel find in Greenland as well.

 

Geologic map of Northern Greenland and Canada, showing known lead-zinc deposits and two mines that have been operated in Canada in relation to the Franklinian sedimentary basin. Source: Geological Survey of Denmark and Greenland.Geologic map of Northern Greenland and Canada, showing known lead-zinc deposits and two mines that have been operated in Canada in relation to the Franklinian sedimentary basin. Source: Geological Survey of Denmark and Greenland.

 

During the rifting of Pangea, The Northern section drifted across a plume of hot material rising from the mantle below. Ca. 61 million years ago, this so-called hotspot caused opening of the North Labrador Sea and highly accentuated melting of the mantle and volcanism at the surface, which is seen as thick layers of basalt on Disko Island, the Nuussuaq Peninsula, Ubekend Ejland, and Svantenhuk Island in Greenland as well as basalt layers of eastern Baffin Island in Canada. After a brief - ca. one million year - period of intense magmatism along the West Coast, Greenland drifted over the hot plume, and rifting and magmatism jumped to the present East Coast ca. 60 million years ago, again causing extensive magmatism.

The East Greenland Paleogene magmatism lasted ca. 8 million years and was most intense during 56-53 million years ago. It is represented by think layers of basalt lava on the Blosseville Coast between Kangerlussuaq and Scoreby Sound and minor occurrences on Hold With Hope and Shannon Island at 75o N. The deeper levels of the magma system are represented by more than 60 intrusions along the central East coast of Greenland from just North of Tasiilaq in the south to Hold with hope in the North. These intrusions are mostly basaltic in composition but include granitic and alkaline rocks.

The passing of the hot-spot has broad implications for magmatic ore deposits along both coasts of Greenland, as well as for the thermal history of the on-shore and off-shore sedimentary basins and thus their petroleum potential. There are several mineralizations hosted by the intrusions that have been identified and to some extend assessed for their economic potential. These include the large palladium and gold mineralization in the Skaergaard intrusion on the central East coast but also includes nickel mineralizations on the West coast.

Sedimentary basins
The rifting of a continent is not normally a clear break, but rather begins with the formation of a series of topographic depressions called basins. As topographic lows, such basins are usually invaded by the sea. Over time they are filled with sediments derived from the rifted continental margins, and carbonate and at times salt deposits from the ocean. The cooling of the lithosphere caused by thinning of the crust in conjunction with loading from the sediments can cause further subsidence in the basins, which allows continued deposition of shallow marine or terrestrial sediments during hundreds of millions of years.


Sedimentary basins are highly interesting as hosts of a wide variety of geologic resources, including oil, gas, and metal ores. Several large sedimentary Basins formed during the break up of Pangea have been found along both the East and West coast of Greenland. The US Geological Survey have assessed the potential for oil and gas in the Arctic region, and found that several basins off-shore Greenland have more than 3 km sediment thickness, less than 500 meter water depth, and greater than 10 % probability for more than 50 million barrels of oil and oil equivalent in natural gas, based on comparison of the geologic context with 246 sedimentary basins with known oil and gas resources.


The conclusion is that there is a good potential for oil and gas of-shore west Greenland and Northeast Greenland, and some potential on-shore in limited areas. The assessments are available from USGS Schenk et al. 2010 and Gautier, 2007, who report the mean probability for West Greenland and adjoining Canada to 7.3 billion barrels of oil and the mean probability for East Greenland to 8.9 billion barrels of oil.

It is important to bear in mind that there is still a probability that none of the Greenland areas contain oil that can be produced. The potential for natural is greater than the potential for oil inside Greenland's economic zone, but due to low prises and very high coast of establishing an infrastructure for production and export, it is predicted that gas production will not be economically viable in the coming two to five decades. Technology for oil production in the ice-filled Greenland water has not yet been developed, and altogether Statoil characterized the Greenland waters as outside the "workable Arctic" at present. The time horizon for oil production from Greenland is probably no earlier than 20 years from now.

 

 

 

 

Mineral potential

A large number of mineral deposits have been identified in Greenland. Some through focused exploration from industry and GEUS and some more or less inadvertently during regional mapping by GEUS and universities. Even, so there is still a large potential for finding further, hitherto unknown, deposits of all sizes including world class. In this respect, North and Northeast Greenland draws special attention to on-shore sedimentary basins with great potentials for zinc, lead, copper and molybdenum. The Paleogene magmatic provinces of East and West Greenland have large potential for magmatic depots of gold, platinum group elements and nickel, and the southern part of Greenland has a geologic setting similar to the South American Cordilleras, and have a large potential for gold, partly documented in widespread gold mineralizations and one gold mine that has been in operation, but which is presently on hold.

Southwest Greenland is host to a province of very unusual magmatic intrusions, of alkaline rock, which have a very high potential for rare earth elements (REE) and other specialty metals including tantalum, niobium, uranium, thorium, beryllium and zirconium. Very large deposits of uranium and REE have been documented in the so-called Ilimaassaq intrusion near the town of Narssaq. Here test mining for uranium was performed during the 1970-ties and presently there are two projects working towards obtaining permission for mining of uranium, REE, zinc and fluorine and REE and zirconium respectively.

These deposits have very large resources, but the concentrations of the metals are relatively low, and the ore is not comparable to other ores for these elements and require tailor made extraction protocols. The question of uranium mining has been and still is a touchy political issue in Greenland and Denmark, and much mythology has filled the news media. The present plans for mining the uranium deposits would produce less than 1 % of the annual global production, although is has frequently been described as "Greenland will become one of the largest uranium producers of the world".

 

Geologic map of South Greenland, showing location of unusual magmatic intrusions of the Gardar Province in red. These intrusions are the hosts of very large mineralizations containing Uranium, rare earth elements, zirconium and other special metals of importance for Hi-tech the industry. Source: Geological Survey of Denmark and Greenland.Geologic map of South Greenland, showing location of unusual magmatic intrusions of the Gardar Province in red. These intrusions are the hosts of very large mineralizations containing Uranium, rare earth elements, zirconium and other special metals of importance for Hi-tech the industry. Source: Geological Survey of Denmark and Greenland.

 


A number of diamond bearing rocks have been found in central West Greenland, but all occurrences have been too small for commercial exploitation. However, there still remains a small potential for diamonds in Greenland.


Kimberlite occurrences in the central West Greenland kimberlite province.  Source: Geological Survey of Denmark and Greenland.Kimberlite occurrences in the central West Greenland kimberlite province. Source: Geological Survey of Denmark and Greenland.

 

. Large identified mineral deposits in Greenland. Source: Geological Survey of Denmark and Greenland.. Large identified mineral deposits in Greenland. Source: Geological Survey of Denmark and Greenland.

 

Regulation of exploration and exploitation of geological resources

Greenland has a comprehensive legislation regulating exploration for and exploitation of mineral and petroleum resources. This also covers regulation of environmental and social impact of such activities, and protocols for securing the highest possible benefit of geologic resource extraction for the Greenland society. Also, the entire Arctic region has agreed though the Ilulissat Declaration, that disputes over rights and responsibilities must be settled according to international law. For this reason, Greenland must be considered equivalent to Western European countries when it comes to regulatory regime for mineral and petroleum extraction.

During the past ten years the number of exploration licenses issued by the Greenland Bureau of Minerals and Petroleum have more than tripled to a present level of ca. 130 licenses. This increase can best be interpreted as caused by a sharp increase in global commodity prices, rather than it can be attributed to geopolitical or climate changes. The mineral industry regards Greenland as one of the 15 most favorable targets for mineral exploration based on a number of relevant parameters (See diagram below).

Most of the exploration companies are from Australia, Canada and Europe, who have near equal shares of ca. one third each. There has been no Asian companies represented until this year (2013) when the first Chinese company was licensed. There has historically been 9 operating mines in Greenland, and there is presently granted 5 licenses for mining, which are based on completed assessment of mineral resources, environmental and social impact assessments and Impact Benefit Agreements with the local municipalities. However, there are no operating mines in Greenland at present.

Minik T. Rosing
Nordic Center for Earth Evolution
Natural History Museum of Denmark
University of Copenhagen
This email address is being protected from spambots. You need JavaScript enabled to view it.

 

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