GEOLOGY OF GREENLAND SURVEY BULLETIN
VOLUME 190

  Igneous layering in kakortokites in the southern part of the Ilímaussaq alkaline complex, South Greenland. The central part of the photograph shows the uppermost part of the layered kakortokite series and the overlying transitional kakortokites and aegirine lujavrite on Laksefjeld (680 m), the dark mountain in the left middle ground of the photograph. The cliff facing the lake in the right middle ground shows the kakortokite layers + 4 to + 9. The kakortokite in the cliff on the opposite side of the lake is rich in xenoliths of roof rocks of augite syenite and naujaite making the layering less distinct. On the skyline is the mountain ridge Killavaat ('the comb'), the highest peak 1216 m, which is made up of Proterozoic granite which was baked and hardened at the contact to the intrusive complex. The lake (987 m) in the foreground is intensely blue and clear because it is practically devoid of life. The whole area is devoid of vegetation, with crumbly rocks typical of the nepheline syenites of the complex.

The Ilímaussaq alkaline complex, South Greenland: status of mineralogical research with new results.

The alkaline complex of Illímaussaq in the Mesoproterozoic Gardar Proince of South Greenland is the type locality for peralkaline, silica-undersaturated agpaitic nepheline syenites and represents an enormous concentration of a number of rare elements, particularly Li, Be, Nb, Zr, REE, Y, U and Th. This explains the presence of about 220 minerals, 27 first described from there, and nine unique to the complex.

Modern investigations of the complex started in the late 1950s, and since 1965 scientific papers on the complex published in various scientific journals have been consecutively numbered under the title 'Contributions to the mineralogy of Illímaussaq'. By 1981 this had reached no. 63 with a progress report on the geology, mineralogy, geochemistry and economic geology of the complex following ten years of intensive field activity.

This bulletin, no 100 in 'Contributions to the mineralogy of Illímaussaq', presents results from the continuing laboratory investigations of material collected during the earlier field work and drilling programmes, together with discussions and reviews of some selected topics in the light of new developments in the study of agpaitic nepheline syenites and their minerals.

Contents

• Colophon, contents, preface
  Brief introduction to the geology of the Ilímaussaq alkaline complex, South Greenland, and its exploration history
  H. Sørensen
  nr190_p001-023.pdf (pdf-file ~2.3 Mb)
• List of all minerals identified in the Ilímaussaq alkaline complex, South Greenland
  O.V. Petersen
  nr190_p025-033.pdf (pdf-file ~0.3 Mb)
• Geochemical overview of the Ilímaussaq alkaline complex, South Greenland
  J.C. Bailey, R. Gwozdz, J. Rose-Hansen and H. Sørensen
  nr190_p035-053.pdf (pdf-file ~1.5 Mb)
• Distribution of germanium in rocks and minerals of the Ilímaussaq alkaline complex, South Greenland
  J.C. Bailey
  nr190_p055-064.pdf (pdf-file ~0.9 Mb)
• The eudialyte group: a review
  O. Johnsen, J.D. Grice and R.A. Gault
  nr190_p065-072.pdf (pdf-file ~0.3 Mb)
• The distribution of minerals in hyper-agpaitic rocks in terms of symmetry: evolution of views on the number and symmetry of minerals
  A.P. Khomyakov
  nr190_p073-082.pdf (pdf-file ~0.2 Mb)
• The hyper-agpaitic stage in the evolution of the Ilímaussaq alkaline complex, South Greenland
  H. Sørensen and L.M. Larsen
  nr190_p083-094.pdf (pdf-file ~0.7 Mb)
• Naujakasite from the Ilímaussaq alkaline complex, South Greenland, and the Lovozero alkaline complex, Kola Peninsula, Russia: a comparison
  A.P. Khomyakov, H. Sørensen, O.V. Petersen and J.C. Bailey
  nr190_p095-108.pdf (pdf-file ~0.7 Mb)
• Zoning in steenstrupine-(Ce) from the Ilímaussaq alkaline complex, South Greenland: a review and discussion
  A.P. Khomyakov and H. Sørensen
  nr190_p109-118.pdf (pdf-file ~0.7 Mb)
• Notes on leucophanite from the Ilímaussaq alkaline complex, South Greenland
  H. Bohse, O.V. Petersen and G. Niedermayr
  nr190_p119-121.pdf (pdf-file ~0.1 Mb)
• Notes on ephesite, terskite, Na-komarovite, ceriopyrochlore-(Ce), joaquinite-(Ce) and other minerals from the Ilímaussaq alkaline complex, South Greenland
  E.I. Semenov
  nr190_p123-125.pdf (pdf-file ~0.1 Mb)
• Thalcusite from Nakkaalaaq, the Ilímaussaq alkaline complex, South Greenland
  S. Karup-Møller and E. Makovicky
  nr190_p127-130.pdf (pdf-file ~0.2 Mb)
• Hiortdahlite II from the Ilímaussaq alkaline complex, South Greenland, the Tamazeght complex, Morocco, and the Iles de Los, Guinea E.R. Robles, F. Fontan, P. Monchoux, H. Sørensen and P. de Parseval
  nr190_p131-137.pdf (pdf-file ~0.3 Mb)
• Natrophosphate from the Ilímaussaq alkaline complex, South Greenland
  O.V. Petersen, A.P. Khomyakov and H. Sørensen
  nr190_p139-141.pdf (pdf-file ~0.1 Mb)
• Two new rare-earth-rich mineral associations in the Ilímaussaq alkaline complex, South Greenland
  I.V. Pekov and I.A. Ekimenkova
  nr190_p143-144.pdf (pdf-file ~0.1 Mb)
• Stability of Na–Be minerals in late-magmatic fluids of the Ilímaussaq alkaline complex, South Greenland
  G. Markl
  nr190_p145-158.pdf (pdf-file ~0.9 Mb)
• A review of the composition and evolution of hydrocarbon gases during solidification of the Ilímaussaq alkaline complex, South Greenland
  J. Konnerup-Madsen
  nr190_p159-166.pdf (pdf-file ~0.6 Mb)
• A note on the occurrence of gold in the Ilímaussaq alkaline complex, South Greenland
  H. Bohse and J. Frederiksen
  nr190_p167.pdf (pdf-file ~0.1 Mb)

Geology of Greenland Survey Bulletin is available from:

Geological Survey of Denmark and Greenland (GEUS),
Øster Voldgade 10, DK-1350 Copenhagen K
Phone: 38 14 20 00, fax: 38 14 20 50, e-mail: geus@geus.dk

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