No. 21 - February 2012

The zinc potential in Greenland

Zinc showings and occurrences arenumerous in Greenland. In particular,the Palaeo zoic Franklinian Basin,North Greenland, which extends formore than 2,500 km E–W through theCanadian Arctic Islands and northernGreenland, and is dominated by geo-logical settings favourable for sedi-ment-hosted zinc deposits, is consid-ered to carry a large potential forhosting undiscovered zinc deposits.Until now the Palaeoproterzoic sedi-

mentary rocks have been the mostimportant Greenlandic zinc source,namely the Black Angel mine.However, zinc is also known from sev-eral occurrences in the Archaean, andthe Meso- to Neoproterozoic andPhanerozoic sedimentary environ-ments of West and East Greenland.

Introduction

A workshop on the 'Assessment of thezinc potential in Greenland' was arranged

by the Geological Survey of Denmark andGreenland (GEUS) and the Bureau ofMinerals and Petroleum (BMP) on 29November - 1 December 2011. The pur-pose of the workshop was to assess thepossible presence of undiscovered zincdeposits in Greenland in the top 1 km ofthe Earth's crust and to rank the mostprospective areas. The procedures for theassessment and ranking of the individualtracts were designed to comply, as muchas possible, with the 'Global Mineral

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2 The zinc potential in Greenland- Assessment of undiscovered

sediment-hosted zinc deposits

500 km

Ice caps / Lakes

Quaternary rock Phanerozoic basins (<400Ma)

Lower Palaeozoic and Neoproterozoic basins

Mesoproterozoic basin

Palaeoproterozoic supracrustal rock

Archaean supracrustal rock

Palaeogene magmatic province

Proterozoic magmatic province

Caledonian magmatic province

Proterozoic basement

Reworked Archaean basement

Archaean basement

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Mine site

Maarmorilik (‘Black Angel’)

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Closed mine site

Cass Fjord

Citronen FjordNavarana Fjord

Petermann Prospect

Kap Wohlgemuth

Kap Schuchert

Repulse HavnHand Bugt

Kayser Bjerg SE

Kayser Bjerg NW

Palaeoproterozoic Pelite Zone of the Ketilidian mobile belt

Palaeoproterozoic Karrat Group

Mesoproterozoic Thule Basin

Palaeoproterozoic Etah Group of the Inglefield mobile belt

Proterozoic Hekla Sund basin

Phanerozoic Franklinian basin

Mesoproterozoic Krummedal Basin &Neoproterozoic Eleonore Bay Basin

Upper Palaeozoic - Mesozoic Jameson Land Basin

Blyklippen

Left figure: Simplified geological map indicating main lithostratigraphic environments and selected zinc occurrences in Greenland. Distributron of the sedi-mentary environments mentioned on page 6-7 are also indicated on the map. Right figure: Total distribution of stream sediment localities in Greenlandand indication of stream sediment localities with zinc values higher than 200 ppm. From Steenfelt (2011) workshop presentation.

Resource Assessment Project' (GMRAP)procedures defined by the U.S. GeologicalSurvey (USGS). One further objective ofthe workshop is to stimulate new explo-ration campaigns in Greenland.

This issue of Geology & Ore highlightssome of the results from the workshop,including descriptions of the most impor-tant sedimentary provinces in Greenland,their known zinc deposits/occurrences andthe resulting potential for undiscoveredzinc deposits within these provinces. Amore comprehensive GEUS survey reportdocumenting the results from the work-shop will be available mid-2012.

The methodology applied

The evaluation of the potential for undis-covered sediment-hosted zinc deposits inGreenland was carried out according to

the standardised process utilised in theGMRAP. In this process, an assessmentpanel of experts discuss all availableknowledge and data for a specific area(tract) and assess the possibility of findingnew undiscovered deposits within thistract. The assessment panel constitutedthirteen geologists from the USGS, GEUS,the BMP, and private exploration compa-nies, each with specific knowledge onaspects of Greenlandic geology and/orexpertise in sediment-hosted zinc deposits.Each tract was defined from the surface to1 km depth. The members of the assess-ment team made their individual estimates(bids) of the number of deposits of a spe-cific size and grade they believe can befound and mined in a specific tract, underthe best of circumstances. A panel discus-sion of the bids led to a consensus bid,which was used as input to a statisticalsimulation. The result was a grade-ton-

nage estimate (prediction) of how muchundiscovered ore and metal that underthe best circumstances can be found with-in a tract. The consensus bids and pre-dicted number of undiscovered zinc de -posits per tract are shown in table 2 onpage 11.

Types of zinc deposit typescovered

Globally, the most important zinc depositsare hosted in clastic-dominated sedimen-tary rock sequences, e.g. the sedimentaryexhalative (SEDEX) deposits, and carbon-ate-hosted zinc deposits, known as Mis -sissippi Valley-Type (MVT). Sediment-host-ed zinc deposits account for approximately43% (SEDEX 38.4% and MVT 4.2%) ofthe world’s zinc production and knownreserves. They are also important sourcesof Pb, Ag and Ba.

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Fluid SourceLarge shallow platform (>105 km2)Seawater evaporation (dolomite & salt)

Fluid DriveDensity-driven reflux hydrothermal dolomitizationContemporaneous evaporite and shale

Distal Expressions of mineralisationMetalliferous black shales,Ba, PO4, Mn

Plumbing SystemLonglived basin faults,Synsedimentary faulting (facies, isopach, breccias, stumps)

Metal TrapAnoxic/Euxinic in bathymetric lowsblack shale with >1% TOC

Rift-Sag sequence (1 to 4 km)Limestone, shale, calcareous shale, siltstone

Hydrothermal dolomiteMVT/Irish types

McArthur River,Century, Meggen

Howards Pass,Tom, Jason

Red Dog

Alkali alterationFe/Mn Carbonate

Rift fill sequence (4-10 km thick, >3 km deep)Coarse oxidised continental clastic rocks: Conglomerates,red beds, sandstones, turbidites, with some siltstones andevaporites, commonly volcanic felsic and mafic sequence

Platform carbonates

Shale, calcares shale siltstone

MVT - Mississippi Valley typeTOC - Total organic carbon

Dolostone

K±Na alterration

Coarse continental clastic rocks with some volcanic felsic and mafic sequence

Crystalline basement

100 km

10 k

m

K±Na alterration

Conceptual model of the geologic setting and geologic assessment criteria for SEDEX and MVT Zn-Pb-Ag deposits modified from Emsbo (2009). Greyarrows represent fluid-flow paths inferred from the distribution of altered rocks and an on-going (in 2009) USGS numerical fluid-flow-modelling project.The locations of several important SEDEX deposits relative to the shallow-water platform margin are indicated and may reflect the structural architectureof the basin or the maturity of the rift cycle.

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Map showing the areas (tracts) used for the zinc assessment workshop.More information about the individual tracts can be found in table 2 onpage 11.

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Tight folds in a moderately folded part of the North Greenland fold belt. The

sequence comprises dark, fine-grained slates and greyish sandstones from the

Ordovician and Lower Silurian that were deposited in the Frank linian Basin.

Locality is in northern Nares Land, North Greenland. The mountainside is

about 350 m high.

SEDEX depositsSEDEX deposits are finely laminated orbedded sulphide ore deposits, interpretedto have formed by release of ore-bearinghydrothermal fluids into a water reservoir,usually the ocean, re sulting in the precipi-tation of stratiform ore. SEDEX depositsare hosted in rift-generated intracratonicor epicratonic sedimentary basins, oftenrelated to a nearby carbonate platform.Deposits occur in carbonaceous shales inbasin sag-phase carbonate rock, shale orsiltstone facies mosaics that were deposit-ed on thick sequences of rift-fill conglom-erates, red beds, sandstones or siltstonesand mafic or felsic volcanic rocks (see con-ceptual model on page 3).

SEDEX deposits are the most importantsources of zinc, and they are typicallyassociated with lead and barite mineralisa-tion. It is common for multiple SEDEXdeposits to be distributed over many tensof kilometres along basin-controlling

faults. Thus, areas along large fault sys-tems with evidence of mineralisation areviewed as very favourable for deposits(Emsbo 2009).

MVT depositsMVT ore deposits are important and havevaluable concentrations of zinc sulphideore hosted in carbonate (limestone, marland dolomite) formations. The mostimportant ore controls are faults and frac-tures, dissolution collapse breccias andlithological transitions. Most MVT depositsare hosted in Phanerozoic rocks and aresignificantly less common in Proterozoicrocks. MVT ores are located in carbonateplatform sequences in passive marginenvironments and are commonly relatedto extensional domains landwards of con-tractional tectonic belts (see conceptualmodel below). The ore bodies range from0.5 million tonnes of contained ore, to 20million tonnes or more, and have gradesof between approximately 3% to 12%

zinc. MVT deposits usually occur in exten-sive districts consisting of several to hun-dreds of deposits (Leach et al., 2010)

Sedimentary environments inGreenland

During the Proterozoic and throughoutthe Palaeozoic and Mesozoic, major inter-continental-rift-related sedimentary basinsand successions formed in West, Northand East Greenland, with sedimentary suc-cessions reaching up to 18 km in thick-ness. The major sedimentary successionsare:(i) Palaeoproterozoic Karrat Group in

West Greenland; (ii) Mesoproterozoic Thule Basin in

North-Western Greenland;(iii) Palaeoproterozoic Etah Group of the

Inglefield mobile belt in western North Greenland;

(iv) Phanerozoic Franklinian basin in North Greenland;

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South–north cross-section of the Franklinian Basin showing the transition from shallow-water carbonate shelf to deep-water, sand- and silt-dominated deposits in the

trough. The succession is continuous from the earliest Cambrian (542 Ma) to the earliest Devonian (about 410 Ma). The shallow-water sediments of the carbonate shelf

pass northwards into a much thicker sequence of clastic, deep-water sediments. The boundary between the shelf and the deep-water trough is a steep escarpment. In the

Silurian, deposition of the turbiditic sediments was very rapid, the trough was filled, and turbidites spread out over the shelf areas. The development of the basin can be

divided into 7 stages (see figure on page 7); S indicates shelf deposits and T trough deposits. Sediment thickness on the shelf was 3–4 km and in the trough about 8 km.

The profile is drawn with a vertical exaggeration. From Henriksen (2008).

(v) Proterozoic Hekla Sund basin, eastern North Greenland;

(vi) Mesoproterozoic Krummedal Basin,Central East Greenland;

(vii) Neoproterozoic Eleonore Bay Basin in Central East Greenland;

(viii) Upper Palaeozoic - Mesozoic Jameson Land Basin, Central East Greenland;

(ix) Palaeoproterozoic Pelite Zone of the Ketilidian mobile belt in South Greenland.

Sedimentary zinc occurrences have beenidentified in nearly all of the above sedi-mentary environments, and the geologicalsettings of the most important environ-ments for sediment-hosted zinc depositsare described in the following:

Karrat GroupThe Palaeoproterozoic supracrustal rocks,known as the Karrat Group, extendsnorth–south for a distance of approx. 550km in North West Greenland, coveringapproximately 10,000 km2. The Grouprests unconformably on an Archaeangneiss complex and consists of a verythick sedimentary package. The KarratGroup was deposited in a very large sub-siding epicontinental basin, suggested torepresent a Palaeoproterozoic passivemargin sequence. It is estimated that thedeposition of the last basinal facies tookplace around 2 Ga ago. The Karrat Groupis divided into a lower and upper KarratGroup, called the Qeqertarssuaq and theNûkavsak Formations, respectively. TheQeqertarssuaq Formation is mostly com-posed of pelite and quartzite, whereas thetop of the formation is characterized byan amphibolite layer interpreted to be vol-canogenic. The maximum thickness of theformation is 3,000 m on the north side ofKangigdleq, but thins abruptly in all direc-tions, to only 140 m thickness 20 km tothe south-east. The Mârmorilik Formation,comprising carbonate units totalling atleast 1,600 m in thickness, is interpretedto be the lateral equivalent to the Qeqer -tarssuaq Formation, deposited to thesouth in a separate basin. The NûkavsakFormation is more than 5,000 m thick andexposed over large areas. It consists ofuniform, coarse-grained to fine-grainedclastic sediments, originally deposited asturbidites. The Archaean basement andthe Karrat Group were deformed andmetamorphosed before they were intrud-ed by the large Prøven Igneous Complex.The Karrat Group can be correlated tothe Foxe Belt of NE Canada. The base-ment and the cover sequence were sub-jected to several phases of strong foldingand thrusting during the Nagsugtoqidian-Rinkian orogenesis and variably affectedby regional metamorphism.

The Inglefield mobile beltInglefield Land is situated in northwestGreenland. The basement consists of Pa -laeoproterozoic juvenile para- and ortho -gneisses; i.e. high-grade supracrustal and

granitoid rocks. The supracrustal rocks,called the Etah Group, are believed to bethe oldest rocks in the area and consist ofgarnet-rich paragneiss, calc-silicate gneiss,marble-dominated units, amphibolite,ultramafic rock and quartzite. The supra -crustal sequence is intruded by the Etahmeta-igneous complex, which is com-posed of intermediate to felsic meta-igneous rocks, metagabbros and ortho -gneisses. The Etah Group and the Etahmeta-igneous complex were metamor-phosed at 1920 Ma under low-pressure tomedium-pressure granulite facies condi-tions, coinciding with at least three phasesof deformation. The Mesoproter ffffozoicThule Supergroup and the Cambriandeposits of the Franklinian Basin overliethe Palaeoproterozoic sequence. TheInglefield Mobile Belt is interpreted as aPalaeoproterozoic arc, formed by conver-gence of two Archaean crustal blocks. The rock sequences of the InglefieldMobile Belt can be correlated acrossnorthern Baffin Bay into Canada, withoutoffset across the Nares Strait.

Franklinian Basin The largest sedimentary basin in Green -land, the Palaeozoic Franklinian Basin,extends E-W for more than 2,500 kilome-tres in northern Greenland and Canada.Deposition in the Franklinian Basin tookplace along a passive continental marginand began in the latest Precambrian andcontinued until at least earliest Devonian.

The sediments were deposited uncon-formably on Proterozoic sandstones andshales and Archaean crystalline basementrocks. The sedimentary succession is sev-eral kilometres thick, and developed intothree different sedimentary environments;a southern broad, shallow-water, domi-nantly carbonate shelf nearest the conti-nent, bordered to the north by a slopewith moderate- to deep-water depthsenvironments and an broad outer shelfdeep-water trough environment in whicha thick flysch succession accumulated. Theshelf succession is dominated by carbon-ates and reaches 4 km in thickness. Theshelf-trough sediments are dominated by

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Composite sedimentary logs of the Franklinian Basin

succession in North Greenland, showing the carbon-

ate-shelf and corresponding deep-water trough

developments. From Henriksen (2008).

siliciclastic rocks, including turbiditic silt-stones and sandstones, terrigenous mud-stones and shales, and have a total thick-ness of approx. 8 km.

The shelf-trough boundary was controlledby deep-seated faults, e.g. the pro-nounced Navarana Fjord escarpment,which, with time, expanded southwardsto new fault lines, with final foundering ofthe shelf areas in the Silurian. The bound-ary between the platform and shelf sedi-mentary regimes fluctuated considerably;in some periods the platform was almostdrowned, while in other periods the plat-form prograded and the platform margincoincided with the shelf-slope break. Theevolution of the Franklinian Basin hasbeen divided into seven stages with signi -ficant changes in regime linked to south-ward expansion of the basin margin. Thenorthern parts of the basin deposits weredeformed in Devonian to Carboniferous

time during the Ellesmerian orogeny witha resulting development of a thin-skinnedfold and thrust zone fold belt in thesouth. A later deformational event affect-ed the northern-most part of thesequence late in the Cretaceous. For amore comprehensive description of thegeological setting of the Franklinian Basinplease refer to Peel & Sønderholm (1991).

The Hekla Sund Basin and EleonoreBay BasinTwo major Neoproterozoic sedimentarybasins that probably formed in responseto an early pulse of Iapetan rifting alongthe Laurentian margin are well exposed inEast Greenland. The Hekla Sund Basin isexposed at the northern termination ofthe East Greenland Caledonides, and it isrepresented by the Rivieradal and HagenFjord Groups, which attain a cumulativethickness of 8-11 km. The evolution ofthis basin reflects deposition during activerifting and a post rift thermal equilibrationstage. A comparison with other Neo pro -terozoic basins along the Laurentian mar-gin of the Iapetus Ocean shows similaritiesbetween the Hekla Sund Basin and coe valdeposits on Svalbard and the CentralHighlands of Scotland.

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Drill core from Citronen Fjord with fine-grainedlaminated sulphides in black mudstone.The sul-phide laminae consist of framboidal pyrite in amatrix of sphalerite and carbonate. Zn-contentin the upper sulphide layer is 25–30% and in thelower layer 1–3%. The core is 3.6 cm across.

Distribution of Zn anomalies and occurrences illustrating favourable trends for zinc deposits in North Greenland. Major tectonic lineaments include the NyboeLand fault zone (NLFZ), the Permin Land flexure, the Navarana fault (dotted lines) and Harder Fjord fault zone (HFFZ). N.L.: Nares Land. F.L.: Freuchen Land.(From Thrane et. al., 2011).

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The Eleonore Bay Basin of East Greenlandcomprises a more than 14 km thick suc-cession of shallow-water sedimentaryrocks. Four stages of basin evolution arerecognised; three stages reflect shelf envi-ronments that are terminated by a changeto shallow-marine siliciclastic to carbon-ate-platform deposition environment.

Jameson Land BasinThe Jameson Land Basin covers approx.13,000 km2 and comprises a stratigraphi-cally almost complete and well exposedsuccession of Upper Palaeozoic-Mesozoicsediments. The composite thickness of thepackage is more than 17 km, with thelower approx. 13 km consisting of conti-nental clastics deposited during MiddleDevonian - Early Permian rifting. In latestPalaeozoic and Mesozoic time, the basinwas dominated by regional subsidencedue to thermal contraction and more than4 km of sediments accumulated. TheUpper Permian Foldvik Creek Group restswith angular unconformity on Devonianto Lower Permian continental clastic sedi-ments, being overlain conformably byTriassic to Cretaceous, mainly marine clas-tic sediments. Tertiary igneous rocksintrude this succession. The approx. 300m thick Upper Permian sequence compri -ses a basal conglomerate, marginal marineevaporites and carbonates (Karstryggenand Wegener Halvø Formations), bitu -minous shale and a shallow marine clasticunit. Stratabound copper-lead-zinc-bariteand celestite occurrences are common inthe Upper Permian and Triassic sediments.

Known sediment-hosted zincoccurrences

With the exception of the Karrat Groupthat hosts the Black Angel zinc-lead minein Central West Greenland, the CitronenFjord deposit in North Greenland, and theformer Blyklippen mine in East Greenland,very limited exploration for zinc has beencarried out in Greenland, and only a fewoccurrences have been investigated inenough detail to allow estimates of overalltonnage and grade. A table of known zincoccurrences in Greenland are found above.

In North Greenland the Palaeozoic Frank -linian Basin, hosting the Citronen FjordZn-Pb deposit, is recognised to host sever-al zinc deposits. The Citronen Fjord de -posit occurs within the deep-water clastictrough sediments of the basin. The globalresource estimate of the Citronen depositis 131.1 Mt at 4.1% Zn and 0.5% Pb at a2% Zn cut-off (Ironbark, pers. comm. Jan.2012). The mineralisation is hosted atthree levels within a 200 m thick sequenceof Ordovician black shales and chert.

The shallow-water platform, shelf andslope facies of the Franklinian Basin arealso known to host several, mainly car-bonate-hosted zinc occurrences e.g. thePetermann Prospect, and the Cass Pros -pect, both in Washington Land, and theoccurrences at Kayser Bjerg, Hall Land,and in the vicinity of Navarana Fjord; noneof these have been investigated in detail.The facies-border and structures that mostlikely have a guiding control on the miner-alising systems within the basin in NorthGreenland can be observed for severalhundred kilometres and may represent anexcellent target for Zn-Pb exploration.

In North West Greenland, sediment-host-ed zinc occurrences are also known from

the Nûkavsak

Formation within the Karrat Group, host-ed within marbles, pelites and cherts, andthese occur intermittently over a strikelength of approx. 9 km. The best outcropso far located is a 15–35 cm thick horizonof massive, dark brown sphalerite assaying41% Zn. The Karrat Group also hosts agreat number of carbonate-hosted Zn-Pbmineralisations, particularly in theMârmorilik Formation. The most famous isthe Black Angel Mine, which comprisesseveral ore bodies, totalling 13.6 Mt at12.3% Zn, 4.0% Pb and 29 ppm Ag.When the mine was closed in 1990approx. 2 million tons of ore where leftbehind, mainly in the pillars. At present acompany is preparing to reopen the mineto extract the pillars. It has been debatedwhether the deposit represents SEDEX orlater stage MVT processes. The otherknown Zn-Pb mineralisations within thesame stratigraphical settings remain to beinvestigated in further detail. New occur-rences have recently been found ingrounds formerly covered by the Inland Ice.

In central East Greenland, within theJameson Land Basin, sediment-hosted zincdeposits are known from both UpperPermian and Upper Triassic strata. The zincmineralisation within the black shales of

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Table of selected zinc prospects, showings and mines in Greenland. Information is extracted from theGEUS-BMP GMOM mineral occurrence database. The individural occurrences are shown on map page 2.

Selected known Zinc occurrences

Class Locality name Type

Deposit Citronen Fjord, Peary Land shale-hosted Zn, Pb

Prospect Cass Fjord, Washington Land carbonate-hosted Zn, Pb, Ba

Prospect Petermann Prospect, Washington Land carbonate-hosted Zn, Pb, Ag

Showing Navarana Fjord, Freuchen Land stratabound Zn, Pb, Ba

Showing Navarana Fjord, Lauge Koch Land stratabound Zn, Pb, Ba

Showing Navarana Fjord, Sulphide zone calcite vein hosted Zn, Ba

Showing Navarana Fjord, Barite zone calcite vein hosted Ba

Showing Kap Schuchert, Washington Land carbonate-hosted Pb, Zn

Showing Kayser Bjerg SE, Hall Land carbonate-hosted Zn, Pb

Showing Kayser Bjerg NW, Hall Land carbonate-hosted Zn, Pb

Showing Kap Wohlgemuth, Nares Land stratabound Zn, Pb, Ba

Showing Hand Bugt, Nyboe Land stratabound Zn, Pb, Ba

Showing Repulse Havn, Nyboe Land stratabound Zn, Pb, Ba

Mine Black Angel/Maarmorilik carbonate-hosted Pb, Zn

Closed mine Blyklippen vein-hosted Pb-Zn

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Part of the Lower and Middle Cambrian sequence in

the south-western corner of Peary Land. The easily

weathered grey-black shales and sandstones of the

Buen Formation (stage 3) are overlain by a promi-

nent crag of banded limestones from the Brønlund

Fjord Group (stage 4, shelf facies). The mountain is

about 800 m high.

the Ravnefjeld Formation is widespreadand has been compared with the Euro -pean Kupferschiefer type.

Potential areas for undiscoveredzinc deposits

At the workshop the assessment teamgave their individual bids at different con-fidence levels, on how many zinc depositsthey thought could be discovered underthe best circumstances. The consensusbids and number of undiscovered zincdeposits per tract are shown in table 2.The distribution of estimated undiscoveredzinc deposits over the different confidencelevels, as well as the increase in numbersfrom one confidence level to another,reflect the level of knowledge about thevarious areas and the overall assessmentof the potential and prospectivity withinthe areas.

The assessment panel agreed that thelargest potential for large grade-tonnagedeposits of the SEDEX zinc type was with-in the trough sequences of (i) the Frank -

linian Basin in North Greenland, (ii) theInglefield mobile belt in western NorthGreenland, (iii) the Rivieradal Group in theHekla Sund Basin in eastern North Green -land, and (iv) the Foldvik Creek succes-sions in the Jameson Land Basin.

The biggest potential for MVT-type zincdeposits was agreed to be within (i) thecarbonate shelf-platform of the Frank linianBasin in North Greenland, (ii) the FoldvikCreek successions in the Jameson LandBasin and (iii) the Mârmorilik formation ofthe Karrat Group in West Green land.

For further discussion and comments tothe different areas and potential, pleaserefer to the more comprehensive GEUSsurvey report documenting the resultsfrom the workshop. This report will beavailable mid-2012.

Concluding remarks

Greenland has operated one of the largestZn-Pb-mines in Europe, the Black Angel,and is generally endowed with thick sedi-

mentary successions that geneticallymatch the criteria for formation of Pb-Zndeposits. Most of the sedimentary succes-sions are under- or unexplored, but areconsidered favourable targets and holdevidence of the mineralising processesneeded to form a zinc deposit. Of particu-lar interest in terms of potentially undis-covered SEDEX type Pb-Zn deposits arethe under-explored parts of the sedimen-tary sequences of the Franklinian Basin inNorth Greenland, which hosts the largeCitronen Fjord zinc deposit, the Inglefieldmobile belt in western North Greenland,the Rivieradal Group in eastern NorthGreenland and the Foldvik Creek group inCentral East Greenland. For the MVT-typezinc deposits, the carbonate platform ofthe Franklinian Basin in North Greenland,the Mârmorilik formation of the Karratgroup in West Greenland and the FoldvikCreek group in Central East Greenland areconsidered to have good potential forundiscovered deposits.

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Table 2. Consensus bids on the number of undiscovered zinc deposits per area (tract).

Consensus bids on the number of undiscovered zinc deposits per area (tract)

Mineralisation Region Area Tract name Areal extent Number of undiscovered Model zinc deposits on different confidence levels * N90 N50 N10 N05 N01

North Greenland Ordovician, Franklinian Basin, Amundsen Land Group SHam_NG_15 184 1 1 2 3 4 Ordovician, Franklinian Basin, Amundsen Land Group SHam_NG_16 655 0 1 2 2 4 Silurian, Franklinian Basin, Trough Sequence SHam_NG_3 30,060 1 2 3 5 10 Silurian, Franklinian Basin, Trough Sequence (metamorphosed) MLme_NG_1 12,780 0 0 2 4 5

West Greenland Palaeoproterozoic, Karrat Group, Nûkavsak Formation SHme_WG1 9,606 0 0 0 0 2 Palaeoproterozoic, Karrat Group, Nûkavsak Formation SHme_WG2 12,650 0 0 0 1 2 Palaeoproterozoic, Karrat Group, Nûkavsak Formation SHme_WG3 606 0 0 1 1 1

SEDEX Northwest Greenland Palaeoproterozoic, Inglefield mobile belt, Etah Group MLme_NW_IG_1 6,464 0 0 1 2 5 Meso - Neoproterozoic, Thule Supergroup MLme_NW_1 4,325 0 0 0 1 4

Northeast Greenland Neoproterozoic, Hagen Fjord Group MLme_NE_HF_1 12,966 0 0 1 2 3 Neoproterozoic - Rivieradal Group, Half-graben sequence MLme_NE_RG_1 7,346 0 0 1 2 4 Central East Greenland Neoproterozoic, Eleonore Bay Supergroup MLme_EBS_1 3,069 0 0 0 1 3 Triassic, Fleming Fjord & Pingodal Formation SHam_T_EG_1 3,258 0 0 0 1 2 Upper Permian, Foldvik Creek Group, Ravnefjeld Fm MLam_P_EG_1 863 0 0 1 2 3 Upper Permian, Foldvik Creek Group MLam_P_EG_2 616 Assessed - but no voting South Greenland Palaeoproterozoic, Ketilidian Pelite zone SHme_S_1 1,065 0 0 0 0 2 North Greenland Silurian, Franklinian Basin, Carbonate shelf-platform CAam_NG_1 51,738 1 3 4 5 8

Northwest Greenland Meso - Neoproterozoic, Thule Supergroup CAme_NW_1 351 0 0 0 1 3

MVT West Greenland Palaeoproterozoic, Karrat Group, Mârmorilik Fm CAme_WG_1 10,585 0 0 0 0 1 Palaeoproterozoic, Karrat Group, Mârmorilik Fm CAme_WG_2 749 0 0 1 1 1

Northeast Greenland Neoproterozoic - Eleonore Bay Supergroup MLme_EBS_1MVT 3,069 0 0 0 1 4

Central East Greenland Upper Permian, Foldvik Creek Group MLam_P_EG_1M 863 0 0 1 2 3 Upper Permian, Foldvik Creek Group, Karstryggen MLam_P_EG_2M 616 0 1 1 2 3

*N90, N50, N10, N05, N01 = Confidence levels; a measure of how reliable a statistical result is, expressed as a percentage that indicates the probability of the result being correct. A confidence level of 10% (N10) means that there is a probability of 10% that the result is reliable.

Key references

Emsbo, P. 2009: Geologic criteria for the assess-

ment of sedimentary exhalative (sedex) Zn-

Pb-Ag deposits: U.S. Geological Survey

Open-File Report 2009−1209, 21 pp.

Ghisler, M. 1994: Ore minerals in stream sedi-

ments from North Greenland. Grønlands

Geologiske Undersøgelse, Open File Series,

94/17, 46 pp.

Harpøth, O., Pedersen, J. L., Schønwandt, H.K.

and Thomassen, B. 1986: The mineral occur-

rences of central East Greenland. Meddelser

om Grønland, Geoscience 17, 138 pp.

Henriksen, N. 1992: Descriptive text to 1:500

000 sheet 7, Nyeboe Land, and sheet 8, Peary

Land, 40 pp.

Henriksen, N., Higgins, A.K., Kalsbeek, F. and

Pulvertaft, T.C. 2000: Greenland from Archaean

to Quaternary. Descriptive text to the

Geological map of Greenland 1:2 500 000.

Geology of Greenland Survey Bulletin 185, 93

pp.

Henriksen, N. 2008: Geological History of

Greenland: Four Billion Years of Earth

Evolution. Geological Survey of Denmark and

Greenland, Ministry of Environment. 270 pp.

Leach, D.L., Taylor, R.D., Fey, D.L., Diehl, S.F. and

Saltus, R.W. 2010: A deposit model for

Mississippi Valley-Type lead-zinc ores, chap. A

of Mineral deposit models for resource assess-

ment: U.S. Geological Survey Scientific

Investigations Report 2010–5070–A, 52 pp.

Peel, J.S. and Sønderholm, M. (ed) 1991. Sedi-

mentary basis of North Greenland. Bull.

Grønlands geol. Unders. 160, 164 pp.

Smith, S.J.H. and Campbell, D.L. 1971: The geol-

ogy of Greenland north of latitude 74°30'N.

Report no. 2. Volume 2. Mineral prospects of

northern Greenland. Internal report, Ponderay

Polar A/S, 62 pp. (Geological Survey of Denmark

and Greenland archives, GEUS Report File

20811).

Steenfelt, A., Thomassen B., Lind, M. and Kyed,

J. 1998: Karrat 97: reconnaissance mineral

exploration in central West Greenland. Geo-

logy of Greenland Survey Bulletin 180, p. 73–80.

Steenfelt, A. 2001a: Calibration of stream sed-

iment data from West and South Greenland.

A supplement to GEUS Report 1999/41.

Danmarks og Grønlands Geologiske Under-

søgelse Rapport 2001/47, 43 pp.

Steenfelt, A. 2001b: Geochemical atlas of

Greenland - West and South Greenland.

Danmarks og Grønlands Geologiske Under-

søgelse Rapport 2001/46, 39 pp., 1 CD-ROM.

Thomassen, B., Clemmensen, L.B. and Schøn-

wandt, H.K. 1982: Stratabound copper-lead-

zinc mineralisation in the Permo-Triassic of

central East Greenland. Bulletin Grønlands

Geologiske Undersøgelse 143, 42 pp.

Thomassen, B. 1991: The Black Angel lead-zinc

mine 1973-90. Rapport Grønlands Geologiske

Undersøgelse 152, p. 46 – 50.

Thomassen, B., Pirajno, F., Iannelli, T.R., Dawes,

P.R. and Jensen, S.M. 2000: Economic geology

investigations in Inglefield Land, North-West

Greenland: part of the project Kane Basin

1999. Danmarks og Grønlands Geologiske

Undersøgelse Rapport 2000/100, 98 pp.

Thrane, K., Steenfelt, A. and Kalvig, P. 2011: Zinc

potential in North Greenland. Danmarks og

Grønlands Geologiske Undersøgelse Rapport

2011/143, 64 pp.

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Citronen Fjord massive sulphide deposit,

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179, 44 pp.

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Front cover photographSandy and muddy turbiditic sediments,part of the fill of the Silurian deep-water trough in Peary Land. The sandysediments occur at the base of eachbed, and silt- and mud-dominatedmaterial form the upper parts of eachgraded unit. The thickness of eachgraded layer can vary between a fewmetres up to about 20 m.

Bureau of Minerals and Petroleum(BMP)

Government of GreenlandP.O. Box 930

DK-3900 NuukGreenland

Tel: (+299) 34 68 00Fax: (+299) 32 43 02

E-mail: bmp@nanoq.glInternet: www.bmp.gl

Geological Survey of Denmark and Greenland (GEUS)

Øster Voldgade 10DK-1350 Copenhagen K

Denmark

Tel: (+45) 38 14 20 00Fax: (+45) 38 14 20 50E-mail: geus@geus.dkInternet: www.geus.dk

AuthorsLars Lund Sørensen, Per Kalvig and

Kristine Thrane, GEUS

EditorsLars Lund Sørensen, Bo Møller

Stensgaard and Karen Hanghøj,GEUS

Graphic ProductionHenrik Klinge Pedersen, GEUS

PhotographsGEUS unless otherwise stated

PrintedFebruary 2012 © GEUS

PrintersRosendahls • Schultz Grafisk a/s

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Cliff section at the head of Navarana Fjord showing the 1300 m high, submarine slope (escarpment) that formed

the north edge of the Silurian shallow-water limestone shelf. The Navarana Fjord escarpment can be traced as a dis-

tinct geological lineament from eastern Peary Land westwards to Nyeboe Land, a distance of more than 500 km.