Mineralium Deposita

, Volume 48, Issue 3, pp 413–421

Emplacement age and thermal footprint of the diamondiferous Ellendale E9 lamproite pipe, Western Australia

  • Noreen J. Evans
  • Brent I. A. McInnes
  • Brad McDonald
  • Martin Danišík
  • Fred Jourdan
  • Celia Mayers
  • Eric Thern
  • Dudley Corbett
Article

DOI: 10.1007/s00126-012-0430-7

Cite this article as:
Evans, N.J., McInnes, B.I.A., McDonald, B. et al. Miner Deposita (2013) 48: 413. doi:10.1007/s00126-012-0430-7

Abstract

The diamondiferous Ellendale 9 (E9) pipe is a funnel-shaped maar-diatreme volcano consisting of inward-dipping tuff sequences intruded by lamproite plugs and dykes. The host rocks for the E9 pipe are Permian sandstones. The multiple lithological contacts exposed within the mined maar volcano provide a natural laboratory in which to study the effect of volcanic processes on U–Th–Pb–He systematics. Zircon from the regional sandstone and E9 lamproite display a bimodal distribution of ages on (U–Th)/He–U/Pb plots. The zircon U/Pb ages for the E9 pipe (n = 52) range from 440 to 2,725 Ma, while the cluster of (U–Th)/He ages for the lamproite dyke zircon indicate that dyke emplacement occurred at 20.6 ± 2.8 Ma, concordant with a maximum emplacement age of about ≤22 Ma from phlogopite 40Ar/39Ar. These ages indicate a xenocrystic origin for the zircon entrained in the E9 dyke. The U/Pb ages of detrital zircon from the regional sandstone host (373–3,248 Ma; n = 41) are indistinguishable from those of the lamproite zircon xenocrysts, whereas the detrital zircon in the host sandstone yield (U–Th)/He ages from 260 to 1,500 Ma. A thermochronology traverse across the E9 lamproite dyke reveals that the zircon (U–Th)/He ages in the host sandstone have not been significantly thermally reset during dyke emplacement, even at the contact. The capability of the zircon (U–Th)/He method to distinguish deep, mantle source lithologies from upper crustal source lithologies could be used in geochemical exploration for diamonds. Pre-screening of detrital samples using etching and helium assay methods will improve the efficiency and decrease the cost of greenfields exploration.

Keywords

Diamond (U–Th)/He U–Pb Lamproite Ellendale Geochronology Thermochronology Exploration 

Supplementary material

126_2012_430_MOESM1_ESM.pdf (139 kb)
ESM 1Analytical methods. Detailed description of all analytical methods used, including (U–Th)/He, U/Pb and Ar–Ar and a more detailed discussion of alpha corrections employed. (PDF 138kb)
126_2012_430_MOESM2_ESM.pdf (154 kb)
ESM 2Full U–Pb data sets. U–Pb SHRIMP data for zircon separated from the Grant Formation sandstone and the E9 Lamproite dyke (PDF 153kb)
126_2012_430_MOESM3_ESM.pdf (148 kb)
ESM 3Thermochronology and Geochronology results. Table 1. Zircon (U–Th)/He and U/Pb ages for double dated E9 Pipe and regional sandstone; Table 2. Zircon (U–Th)/He ages for traverse from E9 lamproite dyke and into adjacent sandstone (PDF 148kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Noreen J. Evans
    • 1
    • 2
  • Brent I. A. McInnes
    • 2
  • Brad McDonald
    • 1
    • 2
  • Martin Danišík
    • 2
    • 3
  • Fred Jourdan
    • 2
  • Celia Mayers
    • 1
  • Eric Thern
    • 4
  • Dudley Corbett
    • 5
  1. 1.CSIRO Earth Science and Resource EngineeringKensingtonAustralia
  2. 2.John De Laeter Center for Isotope Research, Department of Applied GeologyCurtin UniversityPerthAustralia
  3. 3.Department of Earth & Oceanic SciencesThe University of WaikatoHamiltonNew Zealand
  4. 4.Department of Imaging and Applied PhysicsCurtin UniversityPerthAustralia
  5. 5.Kimberley Diamond CompanyEllendale MineAustralia