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.

本数据集汇编了加利福尼亚、墨西哥及秘鲁陆缘各类边缘沉积环境下的沉积物与孔隙水痕量金属浓度、沉积物中铁的化学形态，以及沉积自生相与陆源相铊同位素（thallium isotopes）数据。数据集涵盖了不同底层水氧含量及局地氧化还原地球化学指标，旨在更精准地约束低氧体系中的铊同位素组成。数据显示，常年缺氧位点可保留准确的海水铊同位素组成；而依据孔隙水浓度判定为次氧化的位点（可划分为锰质还原至铁质还原环境）则存在同位素值偏移。氧化环境区段因氧化锰矿物的赋存，呈现出最为偏正的同位素值。