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Contributions to Mineralogy and Petrology

, Volume 44, Issue 2, pp 85–100 | Cite as

Petrology and geochemistry of Easter Island

  • P. E. Baker
  • F. Buckley
  • J. G. Holland
Article

Abstract

Easter Island has developed around three volcanoes—Poike, an older (3 m.y.) strato-volcano, Rano Kau, a caldera, and the fissure complex of Terevaka and its associated cones. The lavas show a wide compositional spread from tholeiites and olivine tholeiites to hawaiites, mugearites, benmoreites, trachytes and rhyolites (comendites). Hawaiite is by far the most abundant rock type and trachytes and rhyolites are relatively rare. Intermediate and acid rocks are concentrated in the southwestern part of the island on or around Rano Kau.

The basaltic rocks, which are plagioclase-phyric or aphyric, are transitional hypersthenenormative types characterized by high contents of Fe, Ti and Zr but low K and Mg. The Poike basalts are marginally lower in Zr, Nb, Y and Zn compared with those of the younger volcanoes, but the trachytes from this centre show anomalously high concentrations of Rb, Zr and Nb.

The island's youngest flow, the Roiho basalt, is an olivine tholeiite with distinctly more alkaline affinities: it is olivine-microphyric with relatively high contents of Mg, Ni and K.

Keywords

Geochemistry Olivine Mineral Resource Rock Type Southwestern Part 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag 1974

Authors and Affiliations

  • P. E. Baker
    • 1
  • F. Buckley
    • 1
  • J. G. Holland
    • 2
  1. 1.Department of Earth SciencesUniversity of LeedsUK
  2. 2.Department of GeologyUniversity of DurhamUK

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