- journal_title：American Mineralogist
- Contributor：Satoko Ishimaru ; Shoji Arai
- Publisher：Mineralogical Society of America
- Date：2008-
- Format：text/html
- Language：en
- Identifier：10.2138/am.2008.2746
- journal_abbrev：American Mineralogist
- issn：0003-004X
- volume：93
- issue：7
- firstpage：1061
- section：Articles
An arsenide (low-Ni, high-Co löllingite) was found in a peridotite xenolith, which is strongly metasomatized by slab-derived melt or fluid from Avacha volcano, located in the Kamchatka arc. This is the first finding of a mantle arsenide within a fresh peridotite xenolith that may have been precipitated from metasomatic fluid/melt ultimately derived from the subducting slab. The löllingite is very low in Ni, suggesting low Ni-Fe partitioning between arsenide and olivine at mantle conditions. This is in contrast to sulfide, which favors Ni over Fe. An As-bearing fluid/melt thus plays some role in the metasomatic Fe enrichment in the mantle wedge. Supply of As is one of the characteristics of the upper mantle beneath the volcanic front.