Improvement of the thallium isotope redox proxy within suboxic to anoxic sediments

Compiled data on trace metal concentrations in sediments and porewaters, Fe speciation in sediments, and sedimentary authigenic and lithogenic thallium isotopes across various marginal settings from the California, Mexico, and Peru margins. These cover various bottom water oxygen contents and local geochemical indicators of redox to better constrain thallium isotopes in low oxygen systems. Data indicate perrenially anoxic sites preserve accurate seawater thallium compositions, while sites deemed suboxic (manganous to ferruginous based on porewater concentrations) have an offset isotopic value. Oxic sections record the most isotopically positive values due to presence of Mn oxides.

本数据集整合了加利福尼亚、墨西哥及秘鲁大陆边缘各类边缘沉积环境中的沉积物与孔隙水痕量金属浓度、沉积物中铁赋存形态（Fe speciation），以及沉积物中自生（authigenic）和陆源（lithogenic）铊同位素（thallium isotopes）相关数据。该数据集涵盖了不同梯度的底层水含氧量及当地氧化还原（redox）地球化学指标，以更好地限定低氧体系中的铊同位素特征。数据显示，常年缺氧的沉积位点可保留准确的海水铊同位素组成；而被判定为次缺氧（suboxic）环境的位点（依据孔隙水浓度可进一步划分为锰还原相至铁还原相）则存在同位素值偏移。氧化环境区段则因氧化锰（Mn oxides）矿物的存在，呈现出最为偏正的同位素值。