U–Pb zircon study of tectonically bounded blocks of 2940–2840 Ma crust with different metamorphic histories, Paamiut region, South-West Greenland: implications for the tectonic assembly of the North Atlantic craton

Since the late 1960s, it has been known that pink and red corundum occur in the area near Fiskenæsset (Qeqertarsuatsiaat) in southern West Greenland. Corundum is hosted in the Fiskenæsset complex, which is part of the Archaean basement of the North Atlantic Craton. To date, c. 40 corundum localities with a wide range of quality are known in the area – a few localities yield stones of gem quality. The most promising locality, Aappaluttoq, is likely to be mined in the foreseeable future by the Canadian company True North Gems (Figs 1, 2A). Red corundum of gem quality is called ruby; gem quality corundum of other colours (e.g. pink, yellow or blue) is called pink sapphire, yellow sapphire etc., while the blue gem corundum is sapphire. Red, pink and blue corundum are also known in smaller quantities from other areas in Greenland.

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Zircon record of the igneous and metamorphic history of the Fiskenæsset anorthosite complex in southern West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/geusb.v20.4980 ◽

1969 ◽

Vol 20 ◽

pp. 67-70 ◽

Cited By ~ 3

Author(s):

Nynke Keulen ◽

Tomas Næraa ◽

Thomas F. Kokfelt ◽

John C. Schumacher ◽

Anders Scherstén

Keyword(s):

North Atlantic ◽

Layered Intrusion ◽

Mineral Chemistry ◽

Joint Project ◽

West Greenland ◽

Metamorphic History ◽

The North ◽

History Of ◽

The North Atlantic ◽

North Atlantic Craton

The Fiskenæsset complex in southern West Greenland is part of the North Atlantic craton and is a layered intrusion consisting of gabbro, ultramafic and anorthositic rocks that was deformed during multiple episodes of folding and metamorphism (Myers 1985). We collected late-stage magmatic hornblenditic dykes and adjacent anorthosites and studied these samples integratively with several in situ techniques to determine the igneous and metamorphic history of the Fiskenæsset complex. The work presented here is part of an ongoing joint project between the Greenland Bureau of Minerals and Petroleum and the Geological Survey of Denmark and Greenland (GEUS). Here we report on new radiometric ages and mineral chemistry data from anorthosites from the North Atlantic craton in southern West Greenland (Fig. 1).

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Manganiferous minerals of the epidote group from the Archaean basement of West Greenland

Bulletin of the Geological Society of Denmark ◽

10.37570/bgsd-2014-62-03 ◽

2014 ◽

Vol 62 ◽

pp. 27-32

Author(s):

A. Katerinopoulou ◽

T. Balic Zunic ◽

J. Kolb ◽

A. Berger

Keyword(s):

North Atlantic ◽

Chemical Compositions ◽

West Greenland ◽

Stages Of Growth ◽

The North ◽

Crystal Chemical Data ◽

Fe And Mn ◽

Mn Content ◽

The North Atlantic ◽

North Atlantic Craton

The chemical compositions and crystal structures of Mn3+-containing minerals from the epidote group in Greenland rocks are investigated and described in detail. They occur in hydrothermally altered Archaean mafic sequences within the gneissic complex of the North Atlantic craton of West Greenland. The Mn-containing minerals have a characteristic red to pink colour. A detailed microchemical study shows a significant inter- and intra-sample variation in Mn content. The samples from different parageneses can be classified as Mn-bearing epidote and Mn-bearing clinozoisite. The intra-sample variation in the content of Al, Fe and Mn is on a very fine scale, but still allows for identification of a negative correlation between Mn and Fe. Textures indicate different stages of growth. Crystal chemical data are compared with literature data and illustrate the basic systematic differences between the influence of Fe and Mn on the crystal structure of the epidote group minerals.

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