The pyroxenite-diamond connection
Pieces of the Earth’s mantle occurring either as tectonic fragments or xenoliths in volcanic rocks are dominantly peridotites, assemblages of olivine, ortho- and clinopyroxene with minor garnet and/or spinel. They frequently contain pyroxene-rich inclusions which have compositions intermediate betwe...
| Main Authors: | , , , |
|---|---|
| Format: | Journal article |
| Published: |
European Association of Geochemistry
2015
|
| _version_ | 1826293429917712384 |
|---|---|
| author | Kiseeva, E Wood, B Ghosh, S Stachel, T |
| author_facet | Kiseeva, E Wood, B Ghosh, S Stachel, T |
| author_sort | Kiseeva, E |
| collection | OXFORD |
| description | Pieces of the Earth’s mantle occurring either as tectonic fragments or xenoliths in volcanic rocks are dominantly peridotites, assemblages of olivine, ortho- and clinopyroxene with minor garnet and/or spinel. They frequently contain pyroxene-rich inclusions which have compositions intermediate between peridotite and basalt. These pyroxenites typically contain varying amounts of more iron-rich (than peridotite) clinopyroxene, orthopyroxene, garnet and/or spinel and are commonly compositionally layered. Surprisingly, despite their subordinate abundance in mantle fragments, pyroxenitic compositions appear be the dominant sources of majoritic garnet inclusions in diamonds, the principal window into the mineralogy of the deep upper mantle and the transition zone (Kiseeva et al., 2013a). In this study we show that the pyroxenite-diamond association is a consequence of the interaction between basaltic and peridotitic compositions in the presence of carbonate melt and that layering of the pyroxenites is a natural consequence of this interaction. Reduction of carbonate to carbon at high pressures is responsible for the genetic connection between pyroxenite and diamond and the abundance of pyroxenitic inclusions reflects this connection rather than a high abundance of this rock type in the mantle. |
| first_indexed | 2024-03-07T03:29:58Z |
| format | Journal article |
| id | oxford-uuid:ba617c07-8847-49bc-abfa-36dbea02fe1e |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:29:58Z |
| publishDate | 2015 |
| publisher | European Association of Geochemistry |
| record_format | dspace |
| spelling | oxford-uuid:ba617c07-8847-49bc-abfa-36dbea02fe1e2022-03-27T05:09:19ZThe pyroxenite-diamond connectionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ba617c07-8847-49bc-abfa-36dbea02fe1eSymplectic Elements at OxfordEuropean Association of Geochemistry2015Kiseeva, EWood, BGhosh, SStachel, TPieces of the Earth’s mantle occurring either as tectonic fragments or xenoliths in volcanic rocks are dominantly peridotites, assemblages of olivine, ortho- and clinopyroxene with minor garnet and/or spinel. They frequently contain pyroxene-rich inclusions which have compositions intermediate between peridotite and basalt. These pyroxenites typically contain varying amounts of more iron-rich (than peridotite) clinopyroxene, orthopyroxene, garnet and/or spinel and are commonly compositionally layered. Surprisingly, despite their subordinate abundance in mantle fragments, pyroxenitic compositions appear be the dominant sources of majoritic garnet inclusions in diamonds, the principal window into the mineralogy of the deep upper mantle and the transition zone (Kiseeva et al., 2013a). In this study we show that the pyroxenite-diamond association is a consequence of the interaction between basaltic and peridotitic compositions in the presence of carbonate melt and that layering of the pyroxenites is a natural consequence of this interaction. Reduction of carbonate to carbon at high pressures is responsible for the genetic connection between pyroxenite and diamond and the abundance of pyroxenitic inclusions reflects this connection rather than a high abundance of this rock type in the mantle. |
| spellingShingle | Kiseeva, E Wood, B Ghosh, S Stachel, T The pyroxenite-diamond connection |
| title | The pyroxenite-diamond connection |
| title_full | The pyroxenite-diamond connection |
| title_fullStr | The pyroxenite-diamond connection |
| title_full_unstemmed | The pyroxenite-diamond connection |
| title_short | The pyroxenite-diamond connection |
| title_sort | pyroxenite diamond connection |
| work_keys_str_mv | AT kiseevae thepyroxenitediamondconnection AT woodb thepyroxenitediamondconnection AT ghoshs thepyroxenitediamondconnection AT stachelt thepyroxenitediamondconnection AT kiseevae pyroxenitediamondconnection AT woodb pyroxenitediamondconnection AT ghoshs pyroxenitediamondconnection AT stachelt pyroxenitediamondconnection |