NATURAL PARTIAL MELTING OF SPINEL LHERZOLITE

Spinel lherzolite nodules from Dreiser Weiher, Germany, contain small glass bearing microcrystalline blebs that were formed from a partial melt. The partial melting occurred during contact anatexis of lherzolite surrounding a deep seated magma chamber in the mantle. The blebs formed from melt drops that were isolated from each other and not from an intergranular film. The results suggest that primary magma originates as small melt drops in a lherzolitic matrix. This evidence indicates a limited mobility of traces of partial melt in the mantle, and suggests that the accumulation of primary magmas formed at very small degrees of partial melting is unlikely. © 1979 Oxford University Press.