Aviat diamonds

a window into the deep lithospheric mantle beneath the northern Churchill Province, Melville Peninsula, Canada

Jennifer Peats*, Thomas Stachel, Richard A. Stern, Karlis Muehlenbachs, John Armstrong

*Corresponding author for this work

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Diamonds from Aviat, on the Melville Peninsula, Canada, display a range in δ 13C from -30‰ to -2‰, with a prominent mode at -5‰. Strongly 13C-depleted diamonds indicate derivation from eclogitic sources and are likely related to precipitation from remobilized, subducted former organic matter. The main population of diamonds around -5‰ may be of eclogitic or peridotitic derivation. Complex CL patterns and abrupt variations in carbon isotopic composition (δ 13C) indicate that at least three episodes of diamond growth occurred, separated by periods of resorption. Nitrogen concentration and δ 13C are decoupled both on the level of individual growth-zones and for the bulk diamond data, indicating that either multiple sources of fluid contributed to diamond formation at Aviat or that nitrogen was fractionated through partitioning into potassium-bearing minerals. Nitrogen-based mantle-residence temperatures for Aviat diamonds mostly fall in the range ∼1050-1150 °C; projected on a syneruptive paleogeotherm of 38 mW/m 2 surface heat-flow, this indicates sampling over a narrow interval between ∼150-170 km depth.

Original languageEnglish
Pages (from-to)611-624
Number of pages14
JournalCanadian Mineralogist
Volume50
Issue number3
DOIs
Publication statusPublished - Jun 2012
Externally publishedYes

Keywords

  • Aviat
  • Canada
  • Carbon isotopes
  • Diamond
  • Eclogite
  • Melville Peninsula
  • Nitrogen
  • Rae Craton
  • Zonation

Fingerprint Dive into the research topics of 'Aviat diamonds: a window into the deep lithospheric mantle beneath the northern Churchill Province, Melville Peninsula, Canada'. Together they form a unique fingerprint.

Cite this