Generation of komatiite magma and gravitational differentiation in the deep upper mantle

Details Generation of komatiite magma and gravitational differentiation in the deep upper mantle Generation of komatiite magma and gravitational differentiation in the deep upper mantle

Feb 1984

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1984e%26psl..67..261o&link_type=abstract

Earth and Planetary Science Letters, Volume 67, Issue 2, p. 261-272.

Other

51

Scientific paper

The densities of silicate liquids with basic, picritic, and ultrabasic compositions have been estimated from the melting curves of minerals at high pressures. Silicate liquids generated by partial melting of the upper mantle are denser than olivine and pyroxenes at pressures higher than 70 kbar, and garnet is the only phase which is denser than the liquid at pressures from 70 kbar to at least 170 kbar. In this pressure range, garnet and some fraction of liquid separate from ascending partially molten diapirs. It is therefore suggested that aluminium-depleted komatiite with a high CaO/Al2O3 ratio may be derived from diapirs which originated in the deep upper mantle at pressures from 70 kbar to at least 140 kbar (200-400 km in depth), where selective separation of pyropic garnet occurs effectively. On the other hand, aluminium-undepleted komatiite is probably derived from diapirs originating at shallower depths (< 200 km). Enrichment of pyropic garnet is expected at depths greater than 200 km by selective separation of garnet from ascending diapirs. The 200-km discontinuity in the seismic wave velocity profile may be explained by a relatively high concentration of pyropic garnet at depths greater than 200 km.

Affiliated with

Also associated with

No associations

Rating

Generation of komatiite magma and gravitational differentiation in the deep 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 Generation of komatiite magma and gravitational differentiation in the deep upper mantle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generation of komatiite magma and gravitational differentiation in the deep upper mantle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1858104