Changes in weathering, elemental cycling, bioproductivity and redox-conditions of shallow to deep marine environments during the Great Oxidation Episode

大氧化期间浅层到深层海洋环境的风化、元素循环、生物生产力和氧化还原条件的变化

• 批准号: 543675433
• 负责人: Professor Dr. Ronny Schönberg, Ph.D.
• 金额: --
• 依托单位: School of Earth and Environmental Sciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/543675433?language=en
• 关键词: Changes; weathering; elemental; cycling; bioproductivity

This project seeks to investigate feedback loops between modes and changes in continental weathering, elemental cycling from source to sink, bioproductivity and redox conditions of shallow to deep marine environments in response to the atmospheric oxygen build-up during the Great Oxidation Episode (GOE). The Pretoria Group of the Transvaal Basin in South Africa is an ideal archive for this study with an almost continuous sedimentary record of the GOE from the 2.32 Ga Timeball Hill Formation – which recently revealed repeated short-term cycling between slightly oxidized and reducing atmospheric conditions via changes between mass-dependent and mass independent fractionation of S isotopes (MDF-S and MIF-S, respectively) – up to the c. 2.08 Ga Magaliesberg Formation – which was deposited during the positive δ13Ccarb excursion of the Lomagundi Event, which has previously been interpreted as a time of oxygen overshoot to near-present O2 levels. Geochemical tools that will be used to retrieve this information are major- and trace element systematics combined with TOC, TN, TS and δ13Corg, δ13Ccarb as well as Fe-Mo-W stable isotope measurements. The project is planned for the duration of 36 months.

该项目旨在反馈大陆风化模式和变化、从源头到汇的元素循环、浅层到深层海洋环境的生物生产力和氧化还原条件之间的反馈循环，以响应大氧化阶段（GOE）期间大气氧气的积累。南非德兰士瓦盆地的比勒陀利亚群是这项研究的理想档案，它拥有来自 2.32 Ga Timeball Hill 地层的 GOE 几乎连续的沉积记录，最近揭示了通过 S 同位素（分别为 MDF-S 和 MIF-S）的质量依赖和质量独立分馏之间的变化，形成轻微氧化和还原的大气条件 - 直至 2.08 Ga Magaliesberg 地层 - 在 δ13Ccarb 正偏移期间沉积。洛马贡迪事件（Lomagundi Event）此前被解释为氧气超调至接近当前氧气水平的时间，将用于检索此信息的地球化学工具是主要和重要的。微量元素系统学与 TOC、TN、TS 和 δ13Corg、δ13Ccarb 以及 Fe-Mo-W 稳定同位素测量相结合 该项目计划持续 36 个月。