Computer Science
Scientific paper
Mar 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996e%26psl.139..213o&link_type=abstract
Earth and Planetary Science Letters, vol. 139, Issue 1-2, pp.213-222
Computer Science
30
Upper Mantle, Layered Materials, Mass Transfer, Elsevier: Upper Mantle, Layered Materials, Mass Transfer, Ar-40/(Ar-36)
Scientific paper
Geochemical arguments for a layered mantle based upon both lithophile and rare gas element abundances are well established. The negative Clayperon slope, associated with phase changes at 670 km, is expected to impede circulation between the upper and lower mantle and induce layering at this depth. Consideration of estimates for the He and Ar isotopic composition of the upper and lower mantle, together with 36 Ar and 40 Ar abundances in the atmosphere, place limits on the mass flux between the lower and upper mantle when combined with estimates for K, U and Th. Using the assumption that rare gases have steady-state abundances in the upper mantle (with residence time = 1 Ga), then the time-averaged mass flux from the lower mantle is 2 · 10 13 kg a -1 . The estimated mass flux is at least 50 times less than the present-day slab flux of ~ 10 15 kg a -1 . The result imposes restriction on the amount of upper mantle material and the frequency with which possible avalanches into the lower mantle might occur and further suggests that models of episodic crustal growth related to such effect are unlikely to be correct.
Keith O'Nions R.
Tolstikhin I. N.
No associations
LandOfFree
Limits on the mass flux between lower and upper mantle and stability of layering 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 Limits on the mass flux between lower and upper mantle and stability of layering, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Limits on the mass flux between lower and upper mantle and stability of layering will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1645831