Collaborative Research: Osmium Isotopes, PGE, and Trace Element Systematics in Kamchatka Sub-Arc Mantle: Implications for Slab-Mantle Interactions

堪察加亚弧地幔的捕虏体表现出不同的岩石学特征，这些岩石学特征归因于在不同的P-T条件下产生的不同成分的板块流体的不同程度的交代作用。本研究将对50-60个岩石学特征良好的捕虏体进行地球化学分析，这些捕虏体代表了变质堪察加弧地幔楔的沿弧和跨弧变化。os同位素和PGE丰度测量将与主元素和亲石微量元素分析相结合，以表征在板块俯冲期间释放到地幔楔的流体，并记录流体-地幔相互作用的过程。高度不兼容的元素与高度兼容的元素的组合使用将为这些过程提供一个独特的视角。此外，在板块-地幔相互作用过程中，PGE的移动程度和PGE的分选类型将对其他构造环境下地幔中可变亲铁元素丰度模式的起源具有重要意义。

9902956WidomXenoliths from the Kamchatka sub-arc mantle exhibit diverse petrographiccharacteristics that have been attributed to variable degrees ofmetasomatism by slab fluids of diverse compositions, generated over a rangeof P-T conditions. This study will involve geochemical analyses of 50-60petrographically well-characterized xenoliths, representing along- andacross-arc variations in the metasomatized Kamchatka arc mantle wedge. Osisotope and PGE abundance measurements will be combined with major elementand lithophile trace element analyses to characterize the fluids releasedto the mantle wedge during slab subduction, and to document the processesof fluid-mantle interaction. The combined use of highly incompatibleelements with highly compatible elements will provide a unique perspectiveon these processes. In addition, the extent of PGE mobility and the typesof PGE fractionations that occur during slab-mantle interactions will haveimportant implications regarding the origin of variable siderophile elementabundance patterns in mantle from other tectonic settings.