Unraveling the sulfur cycle with carbonates: mechanism of incorporation and diagenesis of structurally-substituted-sulfate

揭示碳酸盐的硫循环：结构取代硫酸盐的掺入和成岩作用机制

• 批准号: 218467023
• 负责人: Professor Dr. Harald Strauß
• 金额: --
• 依托单位: Institut für Geologie und Paläontologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/218467023?language=en
• 关键词: Unraveling; sulfur; cycle; carbonates; mechanism

Marine carbonates represent the central archive for reconstructing Earth System evolution in respect to the physical and chemical characteristics of the oceans as well as changes in atmospheric composition and global climate. Biogenic carbonates, carbonate cements and micrites alike have been utilized for reconstructing respective seawater properties. Aside more classical isotopic proxies such as carbon, oxygen, or strontium, an increasing number of studies utilizes trace quantities of sulfate in order to reconstruct the sulfur isotopic composition of seawater sulfate through time. Even more, individual studies interpreted the amount of extracted sulfate as a reflection of the initial oceanic sulfate abundance. Although empirical evidence suggests that the sulfur isotopic composition indeed reflects the isotopic composition of oceanic sulfate at the time of carbonate deposition, no firm understanding about the mechanism of as well as the boundary conditions for sulfate incorporation exists. Furthermore, carbonates are subject to post-depositional diagenetic alteration. Yet, respective effects on the abundance and isotopic composition of this trace constituent in carbonates are largely unknown. Experimental and empirical work proposed here aims at unravelling respective details of sulfate incorporation and its post-depositional alteration in order to place firm constraints on the applicability as a proxy for reconstructing Earth System evolution.

海洋碳酸盐代表了针对海洋物理和化学特征以及大气组成和全球气候变化的重建地球系统进化的中心档案。生物碳酸盐，碳酸盐水泥和微石已用于重建各自的海水特性。除了更古典的同位素代理，例如碳，氧或锶，越来越多的研究还利用了微量的硫酸盐，以通过时间重建海水硫酸盐的硫同位素组成。更重要的是，个体研究将硫酸盐提取的量解释为最初的海洋硫酸盐丰度的反映。尽管经验证据表明，硫同位素组成确实反映了碳酸盐沉积时海洋硫酸盐的同位素组成，但对存在硫酸盐掺入的机理以及边界条件没有任何坚定的了解。此外，碳酸盐会受到沉积后成岩化的改变。然而，对碳酸盐中这种痕量成分的丰度和同位素组成的影响在很大程度上是未知的。此处提出的实验和经验工作旨在揭示硫酸盐掺入及其沉积后改变的各个细节，以便将公司限制放在适用性上，作为重建地球系统演化的代理。