Oxygen Fugacity Across Tectonic Settings

Here we compile published analytical data from lithologies that constrain fO2 (n=860 volcanic rocks - lavas and tephras and n=326 mantle lithologies- the majority peridotites) from ridges, back-arc basins, forearcs, arcs, and plumes. Because calculated fO2 varies with choice of activity model, we re-calculate fO2 for each dataset from compositional data, applying the same set of activity models and methodologies for each data type. Additionally, we compile trace element concentrations (e.g. vanadium) which serve as an additional fO2-proxy. The compiled data show that, on average, volcanic rocks and mantle rocks from the same tectonic setting yield similar fO2s, but mantle lithologies span a much larger range in fO2 than volcanics. Multiple Fe-based oxybarometric methods and vanadium partitioning vary with statistical significance as a function of tectonic setting, with fO2 ridges < back arcs < arcs. Plume lithologies are more nuanced to interpret, but indicate fO2s >= ridges.

搜集汇总

背景与挑战

背景概述

该数据集汇编了来自不同构造环境（如洋脊、弧后盆地、前弧、弧和地幔柱）的火山岩和地幔岩石的氧逸度(fO2)数据，共包含860个火山岩样品和326个地幔岩石样品。通过统一的计算方法和活性模型，数据集揭示了不同构造环境下氧逸度的统计显著性差异，并指出地幔岩石的氧逸度范围比火山岩更广。