High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes

Details High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes

Jul 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003natur.424...57s&link_type=abstract

Nature, Volume 424, Issue 6944, pp. 57-59 (2003).

Computer Science

38

Scientific paper

The high 3He/4He ratio of volcanic rocks thought to be derived from mantle plumes is taken as evidence for the existence of a mantle reservoir that has remained largely undegassed since the Earth's accretion. The helium isotope composition of this reservoir places constraints on the origin of volatiles within the Earth and on the evolution and structure of the Earth's mantle. Here we show that olivine phenocrysts in picritic basalts presumably derived from the proto-Iceland plume at Baffin Island, Canada, have the highest magmatic 3He/4He ratios yet recorded. A strong correlation between 3He/4He and 87Sr/86Sr, 143Nd/144Nd and trace element ratios demonstrate that the 3He-rich end-member is present in basalts that are derived from large-volume melts of depleted upper-mantle rocks. This reservoir is consistent with the recharging of depleted upper-mantle rocks by small volumes of primordial volatile-rich lower-mantle material at a thermal boundary layer between convectively isolated reservoirs. The highest 3He/4He basalts from Hawaii and Iceland plot on the observed mixing trend. This indicates that a 3He-recharged depleted mantle (HRDM) reservoir may be the principal source of high 3He/4He in mantle plumes, and may explain why the helium concentration of the `plume' component in ocean island basalts is lower than that predicted for a two-layer, steady-state model of mantle structure.

Affiliated with

Also associated with

No associations

Rating

High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes 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 High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High 3He/4He ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1884822