Abstract
A variety of alkaline lavas from the Dunedin Volcano have been analyzed for the rare earth elements (REE) La-Yb. The compositions analyzed were: basalt-hawaiite-mugearite-benmoreite; basanite, nepheline hawaiite, nepheline trachyandesite and nepheline benmoreite; trachyte; phonolite. The series from basalt to mugearite shows continuous enrichment in the REE, consistent with a crystal fractionation model involving removal of olivine and clinopyroxene. From mugearite to benmoreite there is a depletion in the REE which is explained by the appearance of apatite as a liquidus phase. The chondrite normalized REE patterns for the phonolites are characterized by strong enrichment and fractionation coupled with a sharp depletion in Eu. Removal of plagioclase from benmoreite magma is suggested for the derivation of the phonolites. The series basanite-nepheline hawaiite, and basanite-nepheline hawaiite-nepheline benmoreite appear to be high pH2O analogues of the series basalt-ben-moreite, with enrichment of the REE being achieved by removal of clinopyroxene, kaersutite and olivine. Compared with other lavas the trachyte has low REE abundances and is characterized by a striking positive Eu anomaly.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Benson, W. N.: Mineralogical notes from the University of Otago, N. Z. No. 3. Trans. Roy. Soc. New Zealand 69, 283–308 (1939).
Benson, W. N.: Cainozoic petrographic provinces in New Zealand and their residual magmas. Am. J. Sci. 239, 537–552 (1941 a).
Benson, W. N.: The basic igneous rocks of Eastern Otago and their tectonic environment. Part I. Trans. Roy. Soc. New Zealand 71, 208–222 (1941 b).
Benson, W. N.: The basic igneous rocks of Eastern Otago and their tectonic environment. Part II. Trans. Roy. Soc. New Zealand 72, 85–118 (1942a).
Benson, W. N.: The basic igneous rocks of Eastern Otago and their tectonic environment. Part III. Trans. Roy. Soc. New Zealand 72, 160–185 (1942b).
Benson, W. N., Turner, F. J.: Mineralogical notes from the University of Otago, N.Z. No. 2. Trans. Roy. Soc. New Zealand 69, 56–72 (1939).
Coombs, D. S.: Dunedin Volcanic Complex and Waipiata Volcanic Formation. N.Z. Dept. Sci. Indus. Res. Information Series No. 51, 54–67 (1965).
Coombs, D. S., White, A. J. R., Hamilton, D.: Age relations of the Dunedin Volcanic Complex and some palaeogeographic implications. New Zealand J. Geol. Geophys. 3, 325–336, 572–579 (1960).
Coombs, D. S., Wilkinson, J. F. G.: Lineages and fractionation trends in unsaturated volcanic rocks from the East Otago Volcanic Province (New Zealand) and related rocks. J. Petrol. 3, 440–501 (1969).
Flower, M. F. J.: Rare earth element distribution in lavas and ultramafic xenoliths from the Comores Archipelago, Western Indian Ocean. Contr. Mineral. and Petrol. 31, 335–346 (1971).
Gill, R. C. O.: Chemistry of peralkaline dykes from the Grønnedal-Ika area, South Greenland. Contr. Mineral. and Petrol. 34, 87–100 (1972).
Green, D. H.: Composition of basaltic magmas as indicators of conditions of origin: application to oceanic volcanism. Phil. Trans. Roy. Soc. London, Ser. A 268, 707–725 (1971).
Gunn, B. M.: The fractionation effect of kaersutite in basaltic magmas. Can. Mineralogist 11, 840–850 (1972).
Haskin, L. A., Frey, F. A., Schmidt, R. A., Smith, R. H.: Meteoritic, solar and terrestrial rare earth distributions. Phys. Chem. Earth 7, 167–321 (1966).
Kesson, S., Price, R. C.: The major and trace element chemistry of kaersutite and its bearing on the petrogenesis of alkaline rocks. Contr. Mineral. and Petrol. 35, 119–124 (1972).
Marshall, P.: The geology of Dunedin (New Zealand). Quart. J. Geol. Soc. Lond. 62, 381–422 (1906).
Marshall, P.: The sequence of lavas at the North Head, Otago Harbour, Quart. J. Geol. Soc. Lond. 70, 382–408 (1914).
Philpotts, J. A., Schnetzler, C. C.: Europium anomalies and the genesis of basalt. Chem. Geol. 3, 5–13 (1968).
Reilly, W. I.: Gravitational expression of the Dunedin Volcano. New Zealand J. Geol. Geophys. 15, 16–21 (1971).
Taylor, S. R.: Geochemical analysis by spark source mass spectrography. Geochim. Cosmochim. Acta 29, 1243–1261 (1965).
Taylor, S. R.: Geochemical application of spark source mass spectrography—II. Photoplate data processing. Geochim. Cosmochim. Acta 35, 1187–1196 (1971).
Ulrich, G. H. F.: On the occurrence of nepheline-bearing rocks in New Zealand. Rep. Australas. Ass. Advmt. Sci. 3, 127–150 (1891).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Price, R.C., Taylor, S.R. The geochemistry of the Dunedin Volcano, East Otago, New Zealand: Rare earth elements. Contr. Mineral. and Petrol. 40, 195–205 (1973). https://doi.org/10.1007/BF00373784
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00373784