Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

11

Scientific paper

The Earth's mantle is chemically and isotopically heterogeneous, and a component of recycled oceanic crust is generally suspected in the convecting mantle [Hofmann and White, 1982. Mantle plumes from ancient oceanic crust. Earth Planet. Sci. Lett. 57, 421 436]. Indeed, the HIMU component (high µ = 238U/204Pb), one of four isotopically distinct end-members in the Earth's mantle, is generally attributed to relatively old (≥ 1 2 Ga) recycled oceanic crust in the form of eclogite/pyroxenite, e.g. [Zindler and Hart, 1986. Chemical geodynamics. Ann. Rev. Earth Planet. Sci. 14, 493 571]. Although the presence of the recycled component is generally supported by element and isotopic data, little is known about its physical state at mantle depths. Here we show that the concentrations of Ni, Mn and Ca in olivine from the Canarian shield stage lavas, which can be used to assess the physical nature of the source material (peridotite versus olivine-free pyroxenite) [Sobolev et al., 2007. The amount of recycled crust in sources of mantle-derived melts. Science 316, 412 417], correlate strongly with bulk rock Sr, Nd and Pb isotopic ratios. The most important result following from our data is that the enriched, HIMU-type (having higher 206Pb/204Pb than generally found in the other mantle end-members) signature of the Canarian hotspot magmas was not caused by a pyroxenite/eclogite constituent of the plume but appears to have been primarily hosted by peridotite. This implies that the old (older than ~ 1 Ga) ocean crust, which has more evolved radiogenic isotope compositions, was stirred into/reacted with the mantle so that there is not significant eclogite left, whereas younger recycled oceanic crust with depleted MORB isotopic signature (< 1 Ga) can be preserved as eclogite, which when melted can generate reaction pyroxenite.

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

Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle 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 Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1562442

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