Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Amitsoq Gneisses

  • Hervé Martin
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_5130-5



The Amîtsoq gneisses are among the older metamorphic rock complexes yet discovered on Earth. These rocks outcrop on the southwestern coast of Greenland, where they extend over more than 50 km northeast of Nûk (Godthåb). The oldest age obtained on a zircon crystal extracted from a tonalitic gneiss sample is of 3.872 ± 0.010 Ga.


The Amîtsoq gneisses outcrop on the southwestern coast of Greenland, where they extend over more than 50 km northeast of Nûk (Godthåb), along the southern coast of the Godthåbsfjord. After long and detailed field work, Mc Gregor (1968, 1973) was the first who recognized these Archaean terrains as among the oldest in the world. He distinguished two groups of gneisses: (1) very old ones cut by mafic dykes (Ameralik dykes) that he called the Amîtsoq gneisses, (2) younger ones emplaced after the Ameralik dykes and that are known as the Nûk gneisses. Both groups are crosscut by the late Qôrqut granite. The first...


Greenland Isua Supracrustal Belt Archaean TTG Gneiss Metamorphic rocks 
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References and Further Reading

  1. Black LP, Gale NH, Moorbath S, Pankhurst RJ, McGregor VR (1971) Isotopic dating of very early Precambrian amphibolite facies gneisses from the Godthaab district, West Greenland. Earth Planet Sci Lett 12:245–259CrossRefADSGoogle Scholar
  2. Bridgwater D, Collerson KD (1976) The major petrological and geochemical characters of the 3600 m.y. Uivak gneisses from Labrador. Contrib Mineral Petrol 54:43–60CrossRefADSGoogle Scholar
  3. Bridgwater D, Schiøtte L (1991) The Archaean gneiss complex of northern Labrador. A review of current results, ideas and problems. Bull Geol Soc Den 39:153–166Google Scholar
  4. Friend CRL, Nutman AP (2005) Complex 3670–3500 Ma orogenic episodes superimposed on juvenile crust accreted between 3850–3690 Ma, Itsaq Gneiss Complex, southern West Greenland. J Geol 113:375–398CrossRefADSGoogle Scholar
  5. Hiess J, Bennett VC, Nutman AP, Williams IS (2009) In situ U-Pb, O and Hf isotopic compositions of zircon and olivine from Eoarchaean rocks, West Greenland: new insights to making old crust. Geochim Cosmochim Acta 73:4489–4516CrossRefADSGoogle Scholar
  6. Horie K, Nutman AP, Friende CRL, Hidaka H (2010) The complex age of orthogneiss protoliths exemplified by the Eoarchaean Itsaq Gneiss Complex (Greenland): SHRIMP and old rocks. Precambrian Res 183:25–43CrossRefGoogle Scholar
  7. Martin H (1986) Effect of steeper Archean geothermal gradient on geochemistry of subduction-zone magmas. Geology 14:753–756CrossRefADSGoogle Scholar
  8. Martin H, Smithies RH, Rapp R, Moyen J-F, Champion D (2005) An overview of adakite, tonalite-trondhjemite-granodiorite (TTG), and sanukitoid: relationships and some implications for crustal evolution. Lithos 79:1–24CrossRefADSGoogle Scholar
  9. McGregor VR (1968) Field evidence of very old Precambrian rocks in Godthaab area, West Greenland. Rapp Gronlands Geol Unders 19:31Google Scholar
  10. McGregor VR (1973) The early Precambrian geology of the Godthåb district, West Greenland. Phil Trans R Soc Lond A 273:243–258CrossRefGoogle Scholar
  11. Moorbath S, O’Nions RK, Pankhurst RJ, Gale NH, McGregor VR (1972) Further rubidium-strontium age determinations on the very eary Precambrian rocks of Godthaab region, West Greenland. Nature 240:78–82ADSGoogle Scholar
  12. Moyen J-F, Martin H (2012) Forty years of TTG research. Lithos 148:312–336CrossRefADSGoogle Scholar
  13. Nutman AP, Bennett VC, Friend CLR, Horie K, Hidaka H (2007) ~3,850 Ma tonalites in the Nuuk region, Greenland: geochemistry and their reworking within an Eoarchaean gneiss complex. Contrib Mineral Petrol 154:385–408CrossRefADSGoogle Scholar
  14. Nutman AP, Bennet VC, Friend CLR, McGregor VR (2000) The early Archaean Itsaq Gneiss Complex of southern Greenland: the importance of field observations in interpreting age and isotopic constrains for early terrestrial evolution. Geochim Cosmochim Acta 64:3035–3060CrossRefADSGoogle Scholar
  15. Nutman AP, Bridgwater D (1986) Early Archaean Amitsôq tonalites and granites of the Isukasia area, southern West Greenland: development of the oldest known sial. Contrib Mineral Petrol 94:137–148CrossRefADSGoogle Scholar
  16. Nutman AP, McGregor VR, Friend CLR, Bennet VC, Kinny PD (1996) The Itsaq gneiss complex of southern Greenland; the world’s most extensive record of early crustal evolution (3900–3600 Ma). Precambrian Res 78:1–39CrossRefGoogle Scholar
  17. Nutman AP, Bennett VC, Friend CLR, Hidaka H, Yi K, Ryeol Lee S, Kamiichi T (2013) The Itsaq Gneiss Complex of Greenland: episodic 3900 to 3660 Ma juvenile crust formation and recycling in the 3660 to 3600 Ma Isukasian orogeny. Am J Sci 313:877–911CrossRefGoogle Scholar
  18. Nutman AP, Hiess J (2009) A granitic inclusion suite within igneous zircons from a 3.81 Ga tonalite (W. Greenland): restrictions for Hadean crustal evolution studies using detrital zircons. Chem Geol 261:76–81CrossRefGoogle Scholar
  19. O’Nions RK, Pankhurst RJ (1978) Early Archaean rocks and geochemical evolution of the Earth’s crust. Earth Planet Sci Lett 38:211–236CrossRefADSGoogle Scholar
  20. Steenfelt A, Garde AA, Moyen J-F (2005) Mantle wedge involvement in the petrogenesis of Archaean grey gneisses in West Greenland. Lithos 79:207–228CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Laboratoire Magmas et VolcansUniversité Blaise Pascal, OPGC, CNRS, IRDClermont-FerrandFrance