Mineralium Deposita

, Volume 35, Issue 8, pp 762–775

Stratigraphical distribution of platinum-group minerals in the Eastern Layered Series, Rum, Scotland

  • M. R. Power
  • D. Pirrie
  • J. C. Ø. Andersen
  • A. R. Butcher
ARTICLE

DOI: 10.1007/s001260050278

Cite this article as:
Power, M., Pirrie, D., Andersen, J. et al. Mineral. Deposita (2000) 35: 762. doi:10.1007/s001260050278

Abstract

Abundant and diverse platinum-group minerals (PGM) occur throughout the Tertiary layered intrusion on Rum, Scotland. In this paper we document the distribution of PGM within the Eastern Layered Series (ELS) on Rum, which comprises 16 alternating units of olivine-dominant feldspathic peridotite grading to plagioclase-dominant allivalite. The PGM occur in six main chrome-spinel layers in the Eastern Layered Series and are clearly associated with minor concentrations of interstitial sulphides. Common PGM phases include: Pd–Cu alloys, Pt–Fe alloys, native Pt, laurite, moncheite, sperrylite, isomertiete, cooperite and braggite along with a large number of other less common arsenide, bismuthotelluride and sulphide phases. Analyses of the discrete chromitite layers yield up to ΣPGE + Au 2618 ppb. Although present throughout the 750-m-thick ELS, there are clear stratigraphical changes in the PGM assemblage. The presence of PGM in the ELS on Rum are interpreted as being caused by mantle melting associated with the proto-Icelandic `hot spot', followed by localised concentration because of the combined effects of magma mixing, sulphide-silicate liquid immiscibility and fractional crystallisation. Most of the PGM are magmatic in origin but some grains show evidence of hydrothermal alteration.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • M. R. Power
    • 1
  • D. Pirrie
    • 1
  • J. C. Ø. Andersen
    • 1
  • A. R. Butcher
    • 2
  1. 1.Camborne School of Mines, University of Exeter, Redruth, Cornwall TR15 3SE, UK e-mail: dpirrie@csm.ex.ac.ukGB
  2. 2.CSIRO Minerals, Pinjarra Hills, P.O. Box 883, Kenmore, Queensland 4069, AustraliaAU