Mineralogical controls on the Ti isotope composition of subduction zone magmas

We have determined the Ti isotope composition of well-characterized, subduction-related basalts, andesites and boninites. Samples from the Solomon Islands, the Troodos ophiolite in Cyprus, and Cape Vogel in Papua New Guinea show small but resolvable variations, that may be related to differences in their mantle sources. Our study highlights that the combination of diagnostic trace element patterns, and Ti isotope compositions in subduction-related igneous rocks can be a powerful tool to constrain petrogenetic processes and to discriminate between different crystallizing mineral phases.

本研究已确定了一系列特征鲜明的俯冲相关玄武岩、安山岩和玻尿酸岩的Ti同位素组成。所采集的萨摩亚群岛、塞浦路斯的特罗多斯蛇绿岩以及巴布亚新几内亚的凯普沃格尔的样品展现出微小但可解析的变异，这些变异可能与它们地幔源头的差异有关。本研究强调了诊断性微量元素模式与俯冲相关火成岩中的Ti同位素组成的结合，可以成为约束岩浆成因过程并区分不同结晶矿物相的强大工具。