Abstract
UNMETAMORPHOSED mafic and ultramafic rocks overlain by Neogene oceanic sediments are exposed on Gorgona Island which is a remnant of the Coastal Cordillera along the Pacific margin of Colombia1. Gorgona is one of the rare places in the world where young pyroxenitic komatiites exhibiting typical quenched spinifex textures (Fig. 1) occur. The spinifex rocks form lenticular bodies (? lava flows) within cumulate ultramafics and troctolitic gabbros and are closely associated with diabases and tholeiitic pillow basalts1. We show here that in textures, rock and mineral chemistry, the Gorgona spinifex rocks are almost identical with the Archean peridotitic to pyroxenitic komatiites from Munro Township (North-east Ontario)2. For this reason the term komatiites is used for the Palaeogene rocks, although one could call them high Mg-tholeiites.
Similar content being viewed by others
References
Gansser, A., Schweiz. Mineral. Petrogr. Mitt. 30, 219–237 (1950).
Arndt, N. T., Naldrett, A. J. & Pyke, D. R. J. Petrol. 18, 319–369 (1977).
Nisbet, E. G., Dietrich, V. J. & Esenwein, A. Fortsche. Miner. (submitted).
Bender, J. F., Hodges, F. N. & Bence, A. E. Earth planet. Sci. Lett. 41, 277–302 (1978).
Kay, R., Hubbard, N. J. & Gast, P. W. J. geophys. Res. 75, 1585–1613 (1970).
Green, D. H., Hibberson, W. O. & Jaques, A. L. in The Earth: Its Origin, Structure and Evolution (ed. McElhinny, M. W., Academic, London, 1978).
Rhodes, J. M., Dungan, M. A., Blanchard, D. P. & Long, P. E. Tectonophysics (in the press).
Frey, F. A., Bryan, W. B. & Thompson, G. J. geophys. Res. 79, 5507–5527 (1974).
Cameron, W. E., Dietrich, V. J. & Gansser, A. Contr. Miner. Petrol. (submitted).
Dietrich, V. J., Gansser, A. & Sommerauer, J. Schweiz. Mineral. Petrogr. Mill. (submitted).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
GANSSER, A., DIETRICH, V. & CAMERON, W. Palaeogene komatiites from Gorgona Island. Nature 278, 545–546 (1979). https://doi.org/10.1038/278545a0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/278545a0
- Springer Nature Limited
This article is cited by
-
Subcompositional Patterns in Cenozoic Volcanic Rocks of Hungary
Mathematical Geology (2005)
-
Re ? Os isotopic constraints on the origin of volcanic rocks, Gorgona Island, Colombia: Os isotopic evidence for ancient heterogeneities in the mantle
Contributions to Mineralogy and Petrology (1991)
-
Petrology and geochemistry of komatiites and tholeiites from Gorgona Island, Colombia
Contributions to Mineralogy and Petrology (1984)
-
Tertiary or Mesozoic komatiites from Gorgona Island, Colombia: Field relations and geochemistry
Contributions to Mineralogy and Petrology (1980)
-
A phase diagram for mid-ocean ridge basalts: Preliminary results and implications for petrogenesis
Contributions to Mineralogy and Petrology (1980)