Behaviour and residence times of lithophile and rare gas tracers in the upper mantle

Details Behaviour and residence times of lithophile and rare gas tracers in the upper mantle Behaviour and residence times of lithophile and rare gas tracers in the upper mantle

Jun 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994e%26psl.124..131o&link_type=abstract

Earth and Planetary Science Letters (ISSN 0012-821X), vol. 124, no. 1, p. 131-138

Other

34

Earth Mantle, Lead (Metal), Lithosphere, Radioactive Isotopes, Rare Gases, Thorium, Uranium, Basalt, Geochemistry, Helium Isotopes, Plumes

Scientific paper

The residence time of highly incompatible lithophile elements in the upper mantle such as Th, U and Pb has previously been estimated at less than or = 1 Ga. The concept of steady-state residence time is extended to include He and other rare gases. For a layered model of the silicate earth long-term storage of the non-radiogenic isotopes of He, Ne and Ar occurs in the lower mantle. The upper mantle is considered to be an extremely degassed reservoir but a source of radiogenic rare gas isotopes. He and other incompatible elements are introduced into the upper mantle by plumes, which bear lower mantle components, and in the case of lithophile elements from the lithospheric boundary layer also. He-3/Ne-22 and He-3/Ar-36 ratios are shown to be similar for the upper mantle and the plume sources, implying that He, Ne and Ar may have similar residence times in the upper mantle. U-238/He-3 ratios are used to show that ca. 90% of the steady-state U and other highly incompatible elements present in the upper mantle are recycled from the lithosphere and only ca. 10% can be introduced directly with He-3 from a lower mantle region. Less than 1% of the lower mantle mass/Ga needs to be entrained into the upper mantle to sustain the present-day He-3 loss rate from ridges.

Affiliated with

Also associated with

No associations

Rating

Behaviour and residence times of lithophile and rare gas tracers in the upper 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 Behaviour and residence times of lithophile and rare gas tracers in the upper mantle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Behaviour and residence times of lithophile and rare gas tracers in the upper mantle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1864838