9304105 Defant The PIs intend to study the way the host magmas interacted with the xenoliths, the macro and micro deformation features, modal abundances, mineral major and trace element chemistries, isotopic (Sr, Nd, Pb, O, H, and Be) analyses, and fluid and melt inclusion studies (Raman). All work will be carried out in the context of careful attention to textural, mineralogical, and petrological evidence used to distinguish those parts of the xenoliths that record different stages in mantle history. Suites of nodules for this study are from several localities. Xenoliths from Batan Island, Luzon arc, Philippines, and Avachinsky Volcano, Kamchatka arc will be the focus of detailed isotopic and trace element work. Xenoliths recovered from Kharchinsky, Shiveluch, Valovayam (Kamchatka arc), and Chirinkotan (Kuriles arc) will be subjected to preliminary chemical studies to form a solid base for more detailed work later, should such studies be warranted. The PIs hope to address questions concerning the composition of the mantle prior to metasomatism, the origin of high-field strength element anomalies characteristic of arc volcanics, the nature of the metasomatizing agent, and the age of the metasomatic event.
