Apollo 15 green glass: chemistry and possible origin.

The paper defines the chemical variation in the Apollo 15 green glass by performing major-element analyses of fragments and spherules from samples 15425, 15426, and 15427. The Apollo 15 green glasses are composed of five chemically distinct groups with finite chemical ranges observed within four groups described in terms of varying percentages of partial melting. The source regions of the five magmas represented by these glasses were products of an earlier differentiation event, and were all chemically distinct, having existed within close proximity to one another at a depth of 400 + or - 50 km. It is concluded that the constraints on the deep lunar interior provided by the Apollo 15 green glasses are consistent with the seismic structure of the lunar mantle.