Inclusions in sublithospheric diamonds

glimpses of deep Earth

T Stachel*, Gerhard P. Brey, JW Harris

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

Diamonds originate in the deep roots of ancient continental blocks (cratons) that extend onto the diamond stability field beneath about 1:0 140 km. Over the last two decades, rare diamonds derived from even greater depths-the deep upper mantle, the transition zone (410-660 km), and the lower mantle-have been recognized. Inclusions in diamonds from the deep upper mantle and the transition zone document sources of basaltic composition, possibly related to subduction of old oceanic crust back into Earth's mantle. Diamonds from the Bower mantle carry inclusions that largely confirm predictions of the composition and mineralogy of the deep mantle based on a "pyrolite" (primitive peridottic) composition of silicate Earth. For some inclusions, however, the chemical evidence again points to a connection with subducting oceanic slabs, possibly ponding at the top of the Bower mantle.

Original languageEnglish
Pages (from-to)73-78
Number of pages6
JournalElements
Volume1
Issue number2
DOIs
Publication statusPublished - Mar 2005
Externally publishedYes

Keywords

  • diamond inclusion
  • majorite
  • perovskite
  • phase transition
  • transition zone
  • lower mantle
  • subduction
  • megalith
  • UPPER-MANTLE
  • PHASE-TRANSFORMATIONS
  • CRYSTALLINE INCLUSIONS
  • TRANSITION ZONE
  • CONSTITUTION
  • KIMBERLITES
  • ULTRADEEP
  • BEARING
  • ORIGIN
  • MODEL

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