Contamination of arctic Fjord sediments by Pb–Zn mining at Maarmorilik in central West Greenland

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Abstract

This study focuses on heavy metal contamination of arctic sediments from a small Fjord system adjacent to the Pb–Zn “Black Angel” mine (West Greenland) to investigate the temporal and spatial development of contamination and to provide baseline levels before the mines re-opening in January 2009. For this purpose we collected multi-cores along a transect from Affarlikassaa Fjord, which received high amounts of tailings from 1973 to 1990, to the mouth of Qaumarujuk Fjord. Along with radiochemical dating by 210Pb and 137Cs, geochemical analyses of heavy metals (e.g. As, Cd, Hg, Pb, and Zn) were carried out. Maximum contents were found at 12 cm depth in Affarlikassaa. After 17 years the mine last closed, specific local hydrographic conditions continue to disperse heavy metal enriched material derived from the Affarlikassaa into Qaumarujuk. Total Hg profiles from multi-cores along the transect clearly illustrate this transport and spatial distribution pattern of the contaminated material.

Introduction

Rising demands from global markets in recent decades has increased pressure on natural resources (e.g. oil, gas, metal-bearing minerals, diamonds, etc.). Thus, numerous investigations and explorations have been carried out during the past three decades, with special focus on arctic regions and their remaining deposits. In particular Greenland, with its old crystalline Precambrian shield, exhibits various sources and types of minerals and ores (Henricksen et al., 2001). Recent explorations in Greenland’s coastal areas discovered at the retreating Inland Ice margin the occurrence of new exploitable resources. However, due to the recent rise in global prices, several previously abandoned mines are due to go into a second run, as for instance the Black Angel Mine at Maarmorilik in central West Greenland.

The Black Angel Mine, once one of the richest Zn mines in the world, was closed in 1990 due to low Zn prices on the world market. A number of studies provide baseline data before exploration began in 1973, monitoring of environmental conditions in the Fjord environment during the initial mining phase (Bondam and Asmund, 1974, Asmund et al., 1975, Bollingberg and Johansen, 1979, Bollingberg and Cooke, 1985). These studies and reports focused mainly on the heavy metal concentration in seawater, seaweed, mussels and fish, showing an anomalously high content of Pb and Zn, accumulated in various organisms and biota (Bollingberg and Cooke, 1985, Larsen et al., 2001, Josefson et al., 2008). Following the discovery of several more ore reserves by Angus & Ross Ltd. Adjacent to the old mine, production re-started in the mine in January 2009, with a new exploration commission granted for the next 25 years.

This study seeks to investigate the present state of contaminated sediments in Affarlikassaa Fjord and Qaumarujuk Fjord. To address this aim a series of multi-cores (20–30 cm long) were collected along an E–W transect, to characterise the temporal and spatial heavy metal distribution from the central Affarlikassaa Fjord to the mouth of Qaumarujuk Fjord. Further we present here a high resolution pollution record from a sediment core taken in the proximity of the tailings outlet area. Moreover, the identified heavy metal-contaminated layer can be used to trace the transport of mining polluted/related particles from the Affarlikassaa Fjord into the Qaumarujuk Fjord and further as a time marker to support and validate our age model based on 210Pb dating.

Section snippets

Environmental settings

The study area is situated within the Archaean Rinkian mobile belt of NE Canada and West Greenland, occurring between latitudes 69°N and 75°N (Escher and Pulvertraft, 1976, Kalsbeek, 1982, Henriksen et al., 2001). The major formation, the Maarmorilik Formation, is characterised by a sequence of calcitic and dolomitic marbles, up to 1200 m thick. Furthermore, a carbonate-hosted Pb/Zn mineralisation as well as stratabound sulphide mineralisation occurs. The ore bodies are up to 30 m thick,

Sediment sampling and bathymetric measurements

Sediment cores were retrieved by using a 50 × 50 × 60 cm giant box-corer and a multi-corer (Table 1), during a cruise of the R/V “Maria S. Merian” (MSM 05/03) to West Greenland in June 2007 (Harff et al., 2007). Coring stations were chosen along an E–W transect from the central Affarlikassaa to the mouth of the Qaumarujuk Fjord based on bathymetric measurements carried out by the Kongsberg (Simrad) EM-120 deep-water and the Kongsberg (Simrad) EM-1200 shallow water multibeam echo sounder and

The Affarlikassaa (A) Fjord

Two sediment cores were collected from the A-Fjord; one from the tailings outlet area (site: 343460) and another from the centre part of the Fjord (site: 343470). Sediments from the A-Fjord are composed of poorly sorted, olive grey to light/dark grey coloured, fine-grained silts and clay. Indications of bioturbation could not be observed. The age model for core 343470 is based on 210Pb and 137Cs using the CRS model and indicates for this core spans the past 60 years. Low contents of 210Pb of

Heavy metal contamination and pollution record

The input of heavy metals into the A- and Q-Fjord was directly caused by suspended heavy metals, released from discharged tailings (Asmund, 1973; Lohring and Asmund, 1989). Earlier post-mining environmental investigations have revealed, that some compounds in the tailings, formed during the flotation process (here: addition of several acids to float Pb and Zn concentrates off) are soluble in the natural marine environment (Asmund, 1980). Presumably a formation of various

Conclusions

The heavy metal contamination of sediments in a small Fjord system adjacent to the Black Angel Mine in central West Greenland was investigated 17 years after mining was abandoned. In the Affarlikassaa Fjord, in direct proximity to the tailings outlet, maximum heavy metal contents are found at 12 cm depth and dated via 210Pb to 1983 and slightly elevated enrichment (EF) factors are found in the surface sediments. Furthermore, surface sediments (0–4 cm depth) taken from the tailings accumulation

Acknowledgements

The authors wish to thank the Deutsche Forschungsgemeinschaft (DFG) for funding the cruise MSM 05/03 with the R/V Maria S. Merian to West Greenland. Further we like to thank Captain and crew for the fantastic work and support during the sampling. Also, we want to thank C. Knudsen from GEUS for arranging the dating of sediment cores in Copenhagen. Moreover, we thank W. Weinrebe for providing the results from bathymetric measurements. For help with laboratory work at IOW we like to thank all

References (44)

  • F. Riget et al.

    Lead, cadmium, mercury and selenium in Greenland marine biota and sediments during AMAP phase 1

    Science of the Total Environment

    (2000)
  • A. Aakrog et al.

    Environmental radioactive contamination in Greenland: a 35 years retrospect

    Science of the Total Environment

    (2000)
  • P.G. Appleby

    Chronostratigraphic techniques in recent sediments

  • G. Asmund

    Environmental survey in relation to mining operations at Maarmorilik, Umanak district, central West Greenland

    Rapport Grønlands Geologiske Undersøgelse

    (1973)
  • Asmund, G., 1980. Water movements traced by metals dissolved from mine tailings deposited in a Fjord in north west...
  • G. Asmund

    Lead and zinc pollution for marine dumping of waste rock from lead/zinc mining

  • Asmund, G., 1992b. Pollution from the marine tailings disposal at the lead-zinc mine at Maarmorilik, West Greenland....
  • G. Asmund et al.

    Continued environmental studies in the Qaumarujuk and Agfardlikavsa Fjords, Maarmorilik, Umanak district, central West Greenland

    Rapport Grønlands Geologiske Undersøgelse

    (1975)
  • G. Asmund et al.

    Managing the environment at the Black Angel Mine, Greenland

    International Journal of Surface Mining, Reclamation and Environment

    (1994)
  • H.J. Bollingberg et al.

    Lead in spotted wolfish, Anarhichas minor, near a zinc-lead mine in Greenland

    Journal of the Fisheries Research Board of Canada

    (1979)
  • J. Bondam et al.

    Environmental studies in the Qaumarujuk and Agfardlikavsa Fjords, Umanak district, central West Greenland

    Rapport Grønlands Geologiske Undersøgelse

    (1974)
  • A. Escher et al.

    Rinkian mobile belt f West Greenland

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