A new lunar high-Ti basalt type defined from clasts in Apollo 16 breccia 60639

摘要: Abstract This paper reports the detailed examination of three basalt clasts from Apollo 16 breccia 60639 that represent a new variant high-Ti returned Moon by mission. Mineral chemistry and whole-rock analyses were conducted on aliquots (breccia matrix, basalt, basalt + breccia matrix). The clasts, which are not overtly porphyritic, contain compositionally zoned pyroxene, olivine, plagioclase crystals evolution magma during crystallization; ilmenite does exhibit major-element compositional zoning within individual crystals. compositions distinct between matrix lithologies. In addition, identify clear differences lithologies in both major trace element concentrations. composition mixed lithology (i.e., matrix) do indicate simple two component mixing intermediate to end-members); this apparent incongruity can be accounted for adding ∼19–40% an amalgamation average clast via impact mixing. Whole-rock consistent with previous one clast, interpreted chemical similarity 11 17 basalts. However, elements suggest examined here have Although similar characteristics variety previously identified types, more extensive reported they type heretofore unrecognized lunar meteorite collections. By placing these context other mare compositions, petrogenetic model basalts found is presented.