Award: OCE-1850789

This project investigated how the decomposition of marine particles at the seafloor impacts the cycling of neodymium (Nd) in the ocean and how that cycling might influence the oceans Nd isotopic signature. The motivation for this work is that the Nd isotope ratio is proving to be a powerful tracer of deep ocean circulation over the past (at least) 10s of millions of years, which has important implications for understanding the global heat transport and the oceans carbon cycle. The primary result of our work establishes that the deep-sea floor, which is often regarded as an unreactive or minor component of ocean supply of trace elements, is a significant source of the Rare Earth Elements and other trace elements at the sea floor. Furthermore, that bottom source exerts an important control over the vertical and global distribution os trace elements and their isotopes within the ocean. While the details can be found in the publications resulting from our work, our research investigated further possible implications of the idea that the marine budget of the Rare Earth Elements would need significant revision, and that the Nd isotope distribution has a complex relationship with the diagenetic phases that are often employed as archival phases for isotope studies that target past environmental conditions. Last Modified: 08/01/2024 Submitted by: BenjaminSTwining