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.

海洋碳酸盐是重建地球系统在海洋物理和化学特征以及大气成分和全球气候变化方面的演变的核心档案。生物成因碳酸盐、碳酸盐胶结物和微晶灰岩等已被用于重建各自的海水性质。除了碳、氧或锶等更经典的同位素替代物外，越来越多的研究利用痕量硫酸盐来重建海水硫酸盐的硫同位素组成。更有甚者，个别研究将提取的硫酸盐数量解释为最初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，但对硫酸盐掺入的机制以及边界条件没有确切的了解。此外，碳酸盐易受沉积后成岩蚀变的影响。然而，碳酸盐中这种微量成分的丰度和同位素组成的各自影响在很大程度上是未知的。这里提出的实验和实证工作的目的是解开各自的硫酸盐掺入和沉积后的蚀变的细节，以放置作为重建地球系统演化的代理的适用性的严格限制。