Collaborative Research: Unlocking the Cenozoic/Cretaceous seawater sulfate record via inclusion of 17O in marine barite

PI将测量海洋沉积物的一种从未分析过的化学性质-硫酸钡颗粒中两种微量氧同位素的变化。这些数据将提供过去1.25亿年来海洋化学变化的记录，这些变化是由地球碳、氧和硫循环的变化驱动的。了解这些元素（碳，氧和硫）的全球循环历史将有助于我们了解地质过程，自然气候变化和陆地和海洋生物过程之间的联系。活动还包括公众宣传（通过描述科学的卡通模块），该项目将支持培养一名研究生。该项目将使用最近开发的方法，对过去1.25亿年来海洋重晶石中硫酸盐中的17 O进行高精度分析，以建立记录。海洋沉积物化学是地质时间尺度上气候演化和地球表面变化的中心目录之一。海洋硫酸盐的硫和氧同位素组成（如在重晶石中捕获的）是过去1.25亿年海洋化学的两个关键记录。它们很重要，因为硫酸盐是微生物生命的能量来源，大约是大气中氧气的10倍，并且整合了广泛的生物地球化学过程和循环，包括碳和铁。最近，一个新的假说被产生，涉及大火成岩省的形成对硫同位素记录的影响。这里提出的新数据--重晶石中的17 O--将被用来检验这一假设，更广泛地说，将被用来更好地理解白垩纪和新生代的C、S和O循环。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

The PIs will measure a never-before-analyzed chemical property of ocean sediments – variations in two trace isotopes of oxygen in barium sulfate particles. These data will provide a record of changes in ocean chemistry over the last 125 million years, changes that are driven by variations in the Earth’s carbon, oxygen and sulfur cycles. Understanding the history of the global cycles of these elements (carbon, oxygen, and sulfur) will help us understand the links between geological processes, natural climate change, and biological processes on land and in the ocean. Activities also include public outreach (via cartoon modules described the science), and the project will support training of a graduate student.This project will build a record of the 17O in sulfate from marine barite over the last 125 million years, using a recently-developed method that enables high-precision analysis of 17O in barite. The chemistry of marine sediments stands as one of the central catalogs of climatic evolution and earth surface change on geological timescales. The sulfur and oxygen isotopic composition of marine sulfate (as captured in barite) are two key records ocean chemistry over the last 125 million years. They are important because sulfate serves as an energy source for microbial life that is roughly 10 times larger than atmospheric oxygen, and that integrates across a wide range of biogeochemical processes and cycles, including those of carbon and iron. Recently, a new hypothesis was generated involving the influence of large igneous province formation on the sulfur isotope record. The new data proposed here – 17O in barite – will be used to test this hypothesis, and more broadly, to better understand the C, S, and O cycles through the Cretaceous and Cenozoic.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.