HENRYMEYERITE IN THE METASOMATIZED UPPER MANTLE OF EASTERN ANTARCTICA

A mineralogical study of lherzolitic and harzburgitic xenoliths of eastern Antarctica shows that the upper mantle of this region has been affected by very strong carbonate metasomatism. We describe for the first time henrymeyerite (Ba 0.97 Ca 0.03 K 0.03 Na 0.11 ) ∑1.14 (Fe 0.92 Mg 0.17 Al 0.02 ) ∑1.11 (Ti 6.66 Si 0.25 ) ∑6.91 O 16 in mantle material. It was found in fine-grained zones containing second-generation clinopyroxene, spinel, olivine, S-bearing chlorapatite, high-Ba, high-Ti phlogopite, calcite, dolomite, Fe-rich magnesite and a mineral of the clinohumite group.

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