Graphite potential in Greenland
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D Graphite potential in Greenland N A
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G Graphite is the most common natural - humic or organic material. These syn - Crystalline flake graphite ly occurring form of crystalline carbon. genetic deposits yield either microcrys - The crystalline flake graphite is the com - It has special characteristics due to its talline or flake graphite (see section on mercially most important form of natural crystallographic structure, making gra - types of graphite), depending on the graphite. It occurs less commonly in nature phite a very important industrial min - metamorphic grade of the host rock. In than microcrystalline graphite but more eral with many applications including low-grade rocks, graphite deposits occur commonly than vein graphite. It occurs in refractories, electrodes and crucibles, as black shales, graphitic slates or graphi - metamorphic rocks such as marble, gneiss - brake linings, lithium-ion batteries, tised coal. For high-grade rocks, graphite es and schist. It consists of many graphene etc. The production of total graphite deposits occur in gneisses, quartzites or sheets stacked on top of each other with in 2017 was 1.2 mio. tonnes. A conser - granulite facies rocks. weak bonds holding them together and vative prediction is that the demand therefor occurs as separate flakes. The for flake graphite will rise 50% by Magmatic sources of graphite are carbon- flake size and crystallinity depends on the 2025 to about 900,000 tonnes per bearing fluids (or, less commonly, melts). The grade and temperature of the metamor - year, especially due to the production graphite deposits form through rapid depres - phism, with amphibolite to granulite facies
of lithium batteries for electric cars. surisation and quenching of CO 2/CH 4-rich metamorphism producing the important fluids, which trigger rapid crystallisation of economic deposits. The large crystals allow In November 2017, a workshop on the fine-grained graphite within breccia matrixes it to be used in more high-valued applica - ‘Assessment of the graphite potential in and fractures in the walls. These deposits tions, such as refractories, foundries and, Greenland’ was arranged jointly by the yield vein graphite. to some extent, in lithium-ion batteries Geological Survey of Denmark and Green- and other battery types. land (GEUS) and the Ministry of Mineral Carbonatitic sources of graphite are Resources (MMR), Government of Green- limestones, marbles and calc-silicate rock. Vein graphite land. This workshop deviated from the These rock types can undergo decarbona - Vein graphite is the rarest, most valuable standard resource assessment procedures tion reactions and thereby form carbonate and highest-quality type of natural gra - applied in previous workshops, because rocks with graphite deposits. These phite. It occurs in solid lumps in veins no statistic grade/tonnage model has been deposits yield either microcrystalline or along intrusive contacts. Vein graphite established. Instead the focus of the work - flake graphite, depending on the meta - results from deposition of carbon-bearing shop was to present and discuss: 1) the morphic grade of the host rock. fluids (or melts) that are channelled graphite value chain, 2) the Nordic gra - through fracture systems. The most eco - phite projects and operations, 3) the cru - nomic significant vein deposits are from cial parameters for graphite occurrence Types of graphite high-grade upper amphibolite to granulite evaluation, and 4) known graphite occur - Natural graphite facies environments. Vein graphite is a rences in Greenland and their potential. Microcrystalline graphite (also known niche market of c. 5,000 tonnes/year. It is as amorphous) used for electrical applications, friction This edition of Geology and Ore provides Microcrystalline graphite is the most abun - products and powdered metal. an overview of: 1) the sources of graphite dant form of graphite but also the lowest- and the deposit types, 2) the graphite priced graphite. This form of graphite Synthetic graphite products, and 3) known graphite occur - commonly occurs as micro-crystalline par - Synthetic graphite is manufactured from rences in Greenland. A GEUS report docu - ticles fairly uniformly distributed in weakly calcined petroleum coke, coal tar pitch, menting results from the workshop is metamorphosed rocks, such as slates, or anthracite, recycled synthetic graphite or available. graphite beds of sedimentary origin. The natural graphite. It is very costly to pro - grade varies and reflects the carbon con - duce synthetic graphite as its precursor tent of the original sediment. Some micro - material has to be baked at high tempera - Sources of graphite crystalline graphite deposits are formed tures of >2500 ˚C for several days. The syn - Graphite deposits can be derived from from contact metamorphism, whereas thetic graphite is of very high quality and biogenic, magmatic or carbonatitic sour - others are a result of regional metamor - has a purity of 99.99%. It is used in high- ces. phism. Micro-crystalline graphite is mainly end products such as electrodes in steel used for lubricants, refractory products, production, and in aluminium production, Biogenic sources of graphite are restrict - paints, drilling mud etc. in lithium-ion batteries for electric vehicles ed to sedimentary environments and the and in the electrical, chemical, nuclear, accumulation of algae, phytoplankton, mechanical and aerospace industries.
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Physical and chemical properties E G The three forms of carbon (charcoal, Advance Bugt graphite and diamond) are distinguished by chemical and physical properties. The gravities of charcoal, graphite and dia - mond are 1.3 – 1.9 g/cm 3, 2.266 g/cm 3 Gable and 3.5 g/cm 3, respectively. Graphite has Gletscher a hardness of 1 to 2 (Mohs scale), which makes it a soft and flexible material. It is Graphite occurrence heat resistant to about 3000 ˚C (in a re - Palaeogene mac volcanics ducing atmosphere) and it is an excellent Phanerozoic sediments conductor of heat and electricity. Graphite Palaeozoic granites is chemically inert, environmentally friend - ly, resists chemical attack by most Mesoproterozoic alkaline plutons reagents and is infusible in most common Langø Mesoproterozoic supracrustals fluxes. Flake graphite has a very high crys - Palaeoproterozoic infracrustal rocks tallinity and a strong anisotropy along the Palaeoproterozoic supracrustal rocks graphene layers causing lubricity. Other Niaqornat Late Archaean granites molecules can intercalate be tween the Archaean basement graphene layers and give it expandable Ilugissoq properties. Qaarsut
Graphite products Giesecke Natural graphite is characterised by many Akuliaruseq parameters, the two most important ones Maligiaq for commercially traded flake graphite being purity (carbon content) and particle Utoqqat size distribution (PSD). High carbon con - Kangikajik tent products have been processed in sev - eral steps for purification and are, there - Auppaluttoq fore, more expensive. Large flakes are more rare and, therefore, attracts higher prices. In contrast, smaller sizes of scree - ned product are cheaper as this material is more abundant. Typically, screened prod - ucts are commercially available in classes Grænseland from –200 mesh (75 mi crons) to +32 Kangerluk 250 km mesh (500 microns). Amitsoq Illukulik
Graphite concentrate, called category 0 product, is usually not sold on the market. Sissarissoq + Kalaaq
Instead, the concentrate is screened into Main lithostratigraphic units in Greenland with location of known graphite occurrences. standard products of different mesh grades (categories 1 and 2). Mines typical - ly have their own advanced screening If the graphite is subsequently milled to a cal graphite, lubricants and graphene have plant and convert their concentrate direct - so-called micronised product, it is classi - a more complex production process. ly into standard products. fied as a category 3 product. These category 4 products are the most expensive. Prices are typically opaque and Special-value added products such as individually agreed to be tween processor/ expandable or expanded graphite, spheri - trader and customers.
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L situated at Amitsoq near Nanortalik, O South Greenland. It was in operation E
G between 1914 and 1924 and it produced c. 6,000 tonnes of ore at an average grade of 21% Cg (graphite in carbon).
Graphite occurrences in Greenland Occurrences of graphite and graphite schist are reported from many localities in Greenland.
South Greenland Amitsoq The Amitsoq Island north of Nanortalik, in South Greenland, encompasses the former Kalaaq Amitsoq graphite mine. Several graphite showings are also reported in the sur - rounding Nanortalik region (see below). The graphite at Amitsoq is hosted by graphitic schists embedded in strongly- sheared cordierite-sillimanite-biotite gneisses. The host rocks are Palaeo - proterozoic high-grade metamorphic Sissarissoq gneisses of the Ketilidian Psam mite zone. The graphite content ranges from c. 20– 35%, with an overall mean graphitic car - bon content of 28.7%. The graphite exists in various morphologies, ranging from fine-grained specular forms to large dis - crete crystals, to agglomerations, which Geological map of known graphite occurrences in the Nanortalik region (Source: Jeroen van Gool). span areas of up to 15 m in size. The average flake size is 0.2 –0.3 mm, but Main applications Historic graphite mining in large flakes up to 15 mm have been Graphite is a very important industrial Greenland reported. The ore genesis is associated mineral with many applications in both Graphite has been known to Greenlanders with volcanogenic massive sulphide (VMS) low-tech industries (lubricants, paints, for several hundreds of years. They formation, as a result of syngenetic depo - drilling mud, brake linings, pencils, etc.) showed specimens to English whalers, sition of organic material from bacteria and in high-tech industries, such as electri - which lead to a British expedition to that thrive in hot sulphide exhalations. cal, chemical, nuclear, mechanical and Greenland in 1845, where 100 tonnes of Subsequent deformation and metamor - aerospace (refractories, electrodes, cath - graphite were quarried from shallow pits phism transformed the organic material odes and anodes in aluminium, etc). In at Langø, West Greenland. Later the into flaky graphite. The old ore-reserve particular, the market for graphite anode- Danish government prohibited this min - figures indicated that the occurrence con - material in lithium-ion batteries is expect - ing. In the beginning of the 19th century tained 250,000 tonnes of graphite (non- ed to grow, reflecting the changes the mining company Grønlandsk Mine - compliant estimate). The current licence induced by expansion of the carbon-free drifts Aktieselskab carried out exploration holder of the area is Alba Mineral Resour- transport sector. Additionally, graphite as for graphite in Greenland. A number of ces. a raw material for graphene, which carries gra phite occurrences and deposits were the potential to be used as electrical con - pro spected by the company and described Nanortalik region incl. Sissarissoq and ductors and for construction material, is by Ball (1923) with other occurrences des - Kalaaq considered to have a substantial growth cribed by Bøggild (1953). The first and The Nanortalik region surrounding potential. only real graphite mine in Greenland was Amitsoq hosts laterally extensive systems
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From the closed Amitsoq graphite mine (Photo: Nanortalik Museum). of graphite occurrences that can poten - Illukulik and Kangerluk contact metamorphism caused by intrud - tially be traced for many kilometres within At Kangerluk, sheared semi-massive ing mafic dykes. The amount of graphite the same tectonostratigraphic level. This graphite lenses are common in rust zones. has reported to be 10,000 tonnes (non- area is considered to carry a high potential A 30 m long and 9 m wide semi-massive compliant resource). The southern part of for undiscovered occurrences. At Sis sa - graphite lens with up to 60% graphite the occurrence is grap hite schist whereas rissoq, west of Nanortalik, a graphite-rich occurs on the north shore of Kangerluk the northern part is an anthracite coal lens, 30 m long and 1.5 m wide, is hosted Fjord hosted by a micaschist. South of layer. in biotite-garnet-schist. Chemical analyses Kangerluk, at Lindenow Fjord, graphite yielded 22–25% Cg and 7–12% S, with a occurs in the Illukulik area both as low West Greenland ratio of flake to amorphous graphite of grade graphite schist and higher grade Utoqqat and Maligiaq 3:7. The current licence holder of the area graphite veins that intrude the schist. At Utoqqat, graphite occurs in Archaean is Alba Mineral Resources. In 2017, Alba gneisses and schists. Seven horizons of Mineral Resources discovered a new Grænseland graphite-bearing schists extend for 1.2 km showing at Kalaaq. It is situated between Coal, anthracite and graphite occur in a and have widths between 1 and 10 m. In Amitsoq and Sissarissoq, and consists of thin sedimentary unit in the Foseelv the beginning of the 1900, 80 tonnes of multiple thick graphite layers that extend Formation near the base of the Ketilidian sample material from two closely spaced for more than 460 m. The grade averages Sortis Group in Grænseland, South-West graphite-bearing zones, sampled at regu - 25% Cg with a maximum of 29% Cg. Greenland. Carbonaceous material was lar intervals, are reported to yield 21% Cg Exploration is ongoing. altered to almost pure graphite during and 5.5% S. Farther to the east, at
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ke ec es Gi
Geological map of the Nordre Strømfjord region with the Akuliaruseq occurrence to the left. The Giesecke occurrence in the middle and Ataneq to the right (Source: 21st North 2013).
Maligiaq, graphite-bearing mica schists At Eqalussuit, just north of Nordre contain numerous 1–20 m wide low- have been sampled over a distance of 800 Strømfjord, the graphite mineralisation grade zones. Resource estimate data m with carbon content in graphite rang - occurs as layers and lenses. This minerali - based on in-fill drill holes (down to 40 m), ing from 5% to 25% Cg. sation, called the Akuliaruseq occurrence, carried out by the current licence holder, is hosted in schists, amphibolites and Graphite Field Resources Ltd., predict a Akuliaruseq ultramafic rocks, which form a narrow, graphite resource of 12.6 million tonnes In the Nordre Strømfjord region, West steeply-dipping synform. The graphite grading 6.3% Cg including a high-grade Greenland, graphite is abundant in occurrence was investigated by Kryolitsel- zone encompassing 2.8 million tonnes Palaeoproterozoic sulphide-rich supra- skabet Øresund A/S between 1982 and grading 12% Cg. crustal rocks. The Nordre Strømfjord 1986. They reported that the graphite was supracrustal belt is particularly enriched. confined to three separate horizons in the Giesecke Here, the graphite is accumulated in a northern limb and is predominately hosted The sequence of felsic garnet ± graphite supracrustal sequence composed of folia - by sillimanite schists that could be fol - ± sillimanite gneiss at Akuliaruseq can be ted biotite garnet ± graphite ± sillimanite lowed along strike for about 6 km. Gra - followed along strike to the north-east to gneiss, locally interlayered with amphibo - phite occurs as two different types: 1) dis - Lake Giesecke and Ataneq, and makes lite, marble bands and ultramafic rocks. seminated graphite flakes, grading 6–8% this area prospective for graphite. The The metamorphic grade is upper amphi - graphite, occurring as both large lumpy graphite is not evenly distributed in the bolite facies. The graphite is considered to flakes and small flakes, none of which gneisses but is concentrated in strata - represent metamorphosed bituminous and contain impurities; and 2) massive bound layers of 0.5 –20 m width. The sulphide-rich strata deposited in a volcanic graphite in intensely deformed parts of graphite concentration in this area varies arc or back-arc environment, associated the schist, grading up to 20–24% Cg. The from 0.5 –7%. with subduction related to the c. 1.85 Ga thickness of the graphite-bearing rocks Nagssugtoqidian Orogeny. varies between 35 and 60 m, but they
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Sampling at the Akuliaruseq occurrence, carried out by Graphite Field Resources (Photo: Claus Østergaard, 21st North).
Qaarsut, Niaqornat and Ilugissoq entire occurrence. Small-scale mining North Greenland At Nuussuaq, West Greenland, three activities were undertaken occasionally Gable Gletscher, Thule District, occurrences of graphite have been regis - between 1908 and 1924, in a 0.2 m thick The Palaeoproterozoic Prudhoe Land tered. Two of the occurrences, Qaarsut graphite layer hosted in a sandstone and supracrustal complex hosts hydrothermally and Niaqornat, are early Cretaceous to shale sequence. overprinted, pyrite- and graphite-rich Palaeocene bituminous shales containing schists with large rust zones estimated to graphite. The third occurrence is the Langø, Upernavik contain 10 –20% of graphite. However, Ilugissoq graphite andesite volcano that South of Upernavik, graphite occurs as the area is underexplored and needs clos - produced pyroclastic rocks and lava flows lenses and veins in pelitic and garnet-bear - er investigation to study the potential for at Nuuk Killeq. The amount of outcrop for ing schist at the island Langø and adjacent graphite. A section at Gable Gletscher was the latter is very large, however, the areas. The host rock is a pegmatite intrud - studied for graphite and returned values graphite content of 2% is very low. The ing the Palaeoproterozoic Karrat Group at of 8.5 and 3.9% Cg, which are consid - sediments at Qaarsut and Niaqornat were the end of the c. 1.85 Ga Nagssugtoqi- ered as minimum values. intruded by Palaeogene mafic dykes, dian –Rinkian Orogeny. The area experi - which caused the carbonaceous matter in enced high-grade metamorphism during Advance Bugt, Inglefield Land, the sediment to be metamorphosed to the Nagssugtoqidian –Rink ian Orogeny. The Palaeoproterozoic Etah Group of amorphous graphite. At Qaarsut, quart- The graphite is crystalline occurring locally Inglefield Land also hosts graphite-rich zitic bituminous shales are metamor - as fibrous crystals up to 2 cm long. Bulk- supracrustal rocks and large rust zones. A phosed over a zone of 3–5 m on both sampling and bench testing in the early 2–3 km long and 500 m wide conforma - sides of an ultramafic dyke. Three samples 20th century yielded high grades of up to ble rust zone is present in the northern from the Qaarsut occurrence were collect - 81% C. However, samples are not docu - part. The rust zone contains disseminated ed and analysed. The results are reported mented to be representative and, despite and semi-massive Fe-sulphides ± gra phite. to yield 93 to 95% Cg and 3.6–4.9% ash. the good quality of the samples, the The graphite content ranges from less These numbers, however, most likely rep - occurrence is small and not considered to than 0.5 to 5% Cg. Three samples were resent ore concentrates or very-rich have economic importance. Today, five measured and contain 2.4% Cg. The oc- graphite-bearing samples or even massive abandoned pits are still visible. They are 1- currence, Advance Bugt, was found by Rio graphite or graphite flakes. As such, they 3 m wide and 5-15 m long and a couple Tinto Mining and Exploration Ltd. in 1991 are probably not representative of the of meters deep. and studied further by GEUS in 1995.
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Old graphite pit at Langø (Photo: Bjørn Thomassen, GEUS).
East Greenland contain several graphite layers. The graphite-bearing supracrustal units in Auppaluttoq graphite-rich layers vary in width from 5 Archaean gneisses were identified. Gra - The Auppaluttoq area is located in the m to 15 m and are discontinuously trace - phite occurs mainly as flake graphite (0.2– Palaeoproterozoic mobile belt of able along three separate ridges for c. 3 mm) hosted in schists. The graphite- Ammassalik, about 60 km north-west of 750 –1,000, 1,500 and 2,000 m. The last bearing zones extend along strike for sev - Tasiilaq. Graphite-bearing supracrustal licence holder, Graphite Field Resources eral kilometres and individual zones are rocks, including biotite and quartzitic Ltd., made two new profiles 400 m apart. typically about 100 m long and 5 m wide. schists, outcrop along the coast west of The analyses yielded a weighted average the Sermilik Fjord. The schists are brown - of 2.3% Cg over 13.2 m. and 7.6% Cg The graphite is hosted in shear zones and ish to greenish grey and fine to medium over 14.5 m. High-grade grab samples of folds where the graphite content decreas - grained. The graphite occurs as millimetre- semi-massive graphite-schist yielded 10.4 es outwards from the shear zones and the thick layers and films alternating with to 30.4% Cg. highest concentrations occur in the largest biotite. The flakes range in length from 1 shear zones. Recon naissance prospecting to 6 mm, with the most common size Kangikajik programmes in the late 1980s and early being 3 –4 mm. In the most distinct miner - Kangikajik peninsula, 100 km north-east 1990s estimated that the potential gra - alised area, the supracrustal schist is of Tasiilaq, is also part of the Palaeopro- phite resource is c. 500,000 tonnes of between 50 m and 100 m thick, and may terozoic mobile belt of Ammassalik. Five graphite (non-compliant resource). Metal -
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Typical colour anomaly in the Prudhoe Land supracrustal complex. View eastwards with Gable Gletscher in the background (Photo: Thomassen et al. 2002). 9
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O Graphite mineralisation at Kangikajik
(Photo: Rosing-Schow et al. 2017). D N A
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lurgical tests yield 9% Cg in the crude ore with 74% of the flakes above 100 mesh. The grade of the graphite concentrate was about 92% Cg with some im purities. Points Assessment results 12,0 Scoreboard – status of occurrences The graphite potential in Greenland is considered to be good, although, graphite 10,0 is still an underexplored commodity. During the workshop, seven graphite 8,0 occurrences were discussed using two dif - ferent scoreboards filled out by the partici - 6,0 pants; some of the occurrences are licensed, some not. One scoreboard char - acterised the current knowledge and sta - 4,0 tus of the individual occurrences. The result from this exercise aligns very well 2,0 with the views expressed by geologists over the past decades – namely, that - there are many positive indicators for graphite in Greenland, but that the tech - nical knowledge of the quality of the graphite from the known occurrences is limited. The other scoreboard shows the Grain-character Crystallinity Ɵ Į Ɵ Ɵ activities the participants recommend to Grade Depth/shape TonnageƟ By-products/penal es (chem/phys) advance the knowledge of the occur - Bene cia on amenability Market solu on rences. This scoreboard assessment result - Exploita on ed in a range of recommendations reflect - Average scoreboard points obtained for each occurences showing how the knowledge status was evaluated for the seven occurrences included in the assessment.
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Outcropping semi-massive graphite-schist mostly rusty and coated by iron sulphate at Auppaluttoq (Photo: 21st North).
ing the low level of knowledge. The rec - ommendations for most of the occur - ĚĨŽƌĂĐƟǀŝƟĞƐ Ɵ rences follow the traditional geological knowledge build-up, starting with field - % of votes work such as mapping, sample collection 90 Scoreboar recommenda ons and geophysics. 80 However, more laboratory analyses of the 70 collected samples such as geochemistry 60 and petrography were recommended 50 reflecting the need to gain more data 40 regarding the quality of the graphite, and 30 thus, metallurgical tests were recommend - ed. This was in particular the case for the 20 advanced and licensed occurrences, such 10 Ʃ as Akuliaruseq and Amitsoq, for which 0 metallurgical tests and laboratory studies Auppalu oq Akuliaruseq Giesecke Amitsoq Sissarissoq Kangikajik Illukulik are prioritised and investigations on defin - Lab studies Field/geophys Trench/drilling ing the ore-body given lower priority. Metallurgical Market studies Economic studies Scoreboard showing which activities the participants recommended for the seven occurrences.
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E R O
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Y The Ministry of Mineral Resources
G (MMR)
O Government of Greenland
L Postbox 930
O Imaneq 1A, 201
E 3900 Nuuk
G Greenland
Tel: (+299) 34 68 00 Fax: (+299) 32 43 02 E-mail: [email protected] Internet: www.govmin.gl www.naalakkersuisut.gl, www.greenmin.gl
Typical graphite-pyrite schist, west of Gable Gletscher. Logo is 8.5 cm (Photo: Thomassen et al. 2002).
Additional reading
Ball, S.H. 1923: The mineral resources of Nielsen, B.L. 1973: A survey of the economic Greenland. Meddr. Grønland 63 , 1, 1-60. geology of Greenland (exclusive fossil fuels). Berthelsen, A. & Henriksen, N. 1975: Geological Rapp. Grønl. Geol. Unders. 56 (45 pp). Geological Survey of Denmark map of Greenland 1:100,000 Ivigtut 61 V.1 Syd. Sharp, G. 1991: Gossan search on Inglefield Land, and Greenland (GEUS) The orogenic and cratongenic geology of a North West Greenland, 22 p. Unpublished report, Øster Voldgade 10 Precambrian Shield area. Grønlands Geologiske RTZ Mining and Exploration Ltd., Bristol, UK, DK-1350 Copenhagen K Undersøgelse. GRF. No. 21084. Denmark Bøggild, O.B. 1953: The mineralogy of Greenland. Simandl, G.J. 2015: Graphite deposit types, their Meddr. Grønland 149 (3), 422 pp. origin, and economic significance. British Tel: (+45) 38 14 20 00 Bondam, J. 1992: Graphite occurrences in Columbia geological survey paper 2015-3. E-mail: [email protected] Greenland – a review. Open file series 92/6. Steensgaard, B.M. , Stendal, H., Kalvig, P. & Internet: www.geus.dk Geological survey of Greenland. Hanghøj, K. 2016: Review of potential resources Høeg, E . 1915: Extrakt af Grafitrapporter, Grønl - for critical minerals in Greenland. Center for min - ands Minedrift (A/S (in archives of Geological erals and materials report, 2016/3. Survey of Denmark and Greenland, GEUS Report Taylor Jr., H.A. 2006: Graphite. In: Kogel, J.E., Front cover photograph File 21148), 11 pp. Trivedi, N.C., Barker, J.M. & Krukowski, S.T. (eds): Auppaluttoq area Kalvig, P. 1992: Geologiske undersøgelser af Industrial minerals and rocks. 7th edition, pp. (21st North) grafitforekomsten Kangikajek, Tasiilaq Kommune. 507-518. Internal report, Tasiilaq Kommune, 41. Thomassen, B., Krebs, J.D. & Dawes, P.R . 2002: Kalvig, P. 1994: Industrial mineral occurrences in Qaanaaq 2001: mineral exploration in the Olrik Greenland – a review. GGU Open file Series 94/4, 94. Fjord – Kap Alexander region, North-West Rosing-Schow, N., Bagas, L., Kolb, J., Balic- Greenland. Danmarks og Grønlands Geologiske Authors and editors Zunic, T., Korte, C. & Fiorentini, M.L. 2017: Undersøgelse Rapport 2002/86, 72 pp. Kristine Thrane, Per Kalvig GEUS Hydrothermal flake graphite mineralization in Thrane, K. & Kalvig, P. 2019: Graphite potential Paleoproterozoic rocks of south-east Greenland. in Greenland. Reporting on the 9th Greenland Graphic Production Henrik Klinge Pedersen, GEUS Miner. Deposita 52, 769-789. Mineral Resource Assessment Workshop. Lindaas, G. 1915: Rapport over expeditionen til Danmarks og Grønlands Geologiske Undersøgelse Photographs Upernavikdistriktet. sommeren 1915. internal Rapport (in press). GEUS unless otherwise stated report, Grønlands Minedrifts A/S, 25 pp. (GRF no. 21150). Printed Morthost, J. & Keto, L. 1984: Report on the January 2019, graphite exploration in Aluliaruseq area. 1983. Internal report, Kyoliteselskabet Øresund A/S. Printers Vol. 1, 29 pp. 22 plates. Vol. 2 (drilling statistics Rosendahls A/S and core-logs). ISSN 1602-818x (print) 2246-3372 (Online)
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