The molybdenum (Mo) isotope composition (defined as δ98Mo measured per mil relative to NIST-3134) of many modern arc systems and the upper continental crust is heavier than the mantle and most subducting slab lithologies. This observation has led to a model whereby fluids leaving the slab transfer isotopically heavy Mo preferentially to the mantle wedge, leaving the residual slab isotopically lighter. We explore this model via an Mo isotope study of the metasedimentary and mélange lithologies of the Catalina Schist in California. These rocks record subduction zone metamorphism over a wide range of high-pressure/low-to-medium temperature conditions.

中文翻译：

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俯冲带变质过程中的钼同位素行为


许多现代弧系统和上部大陆地壳的钼 （Mo） 同位素组成（定义为相对于 NIST-3134 每密耳测量的 δ98Mo）比地幔和大多数俯冲板岩性重。这一观察结果导致了一个模型，其中离开板块的流体优先将同位素重的 Mo 转移到地幔楔中，使残留板块的同位素更轻。我们通过对加利福尼亚 Catalina 片岩的变质沉积岩性和混合岩性的 Mo 同位素研究来探索这个模型。这些岩石在广泛的高压/中低温条件下记录了俯冲带变质作用。