Nanocrystalline diamond from the Earth's mantle underneath Hawaii

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

9

Scientific paper

Melt inclusions in a mantle-derived garnet pyroxenite xenolith from Salt Lake Crater (Hawaiian island of Oahu) have been analysed by means of transmission electron microscopy, including energy dispersive X-ray analysis, electron energy-loss spectroscopy and electron diffraction. The melt inclusions represent trapped low-degree melt that metasomatised the Hawaiian mantle lithosphere before the eruption of the host magma. The inclusions consist of a C-Cl-S-rich glass of basaltic composition, an exsolved gas-fluid phase (mainly CO2 with minor amounts of CO, H2O, and some unidentified C-H and H-S species) and/or carbonate. Diamond is the major phase in the glass, ranging in size between a few and several hundred nanometres. Two varieties of nanocrystalline diamonds are identified. Polycrystalline aggregates of nanometre-size diamonds are tentatively explained as pseudomorphs after carbonate, while single crystals are suggested to have crystallised from the melt. Other nanocrystalline phases include native Fe and Cu, FeS, FeS2, ZnS, AgS and several Ti, Nb, Zr, Ir, In, Pd-rich phases of unknown composition. Overall, the observed mineral assemblage suggests that the melt was highly reduced and strongly enriched in volatiles and trace elements of contrasting geochemical affinity. Our findings are the first evidence for a metasomatic impregnation of the Hawaiian mantle by low-degree melts. Here, we report the first occurrence of diamond in the modern oceanic mantle.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Nanocrystalline diamond from the Earth's mantle underneath Hawaii does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Nanocrystalline diamond from the Earth's mantle underneath Hawaii, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nanocrystalline diamond from the Earth's mantle underneath Hawaii will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1821740

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.