Collaborative Research: Interpreting the record of Antarctic sediment influenced by metal-rich hydrothermal deposits from their accumulation through early diagenesis and burial

GSTDTAP

项目编号	1847509
	Collaborative Research: Interpreting the record of Antarctic sediment influenced by metal-rich hydrothermal deposits from their accumulation through early diagenesis and burial
	Natascha Riedinger (Principal Investigator)
主持机构	Oklahoma State University
项目开始年	2019
	2019-04-15
项目结束日期	2020-03-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	64927(USD)
国家	美国
语种	英语
英文摘要	The Antarctic region is surrounded by spreading centers, areas on the seafloor where volcanic eruptions and vigorous hydrothermal venting typify the environment. Hydrothermal venting releases metals into the water column. These metals are of some economic interest as a natural resource, and they can impact the biosphere, including affecting faunal composition and microbial processes that dominate in the region. Additionally, hydrothermal metals settle onto the seafloor along with other sediments. Marine sediments provide a window into the past as they accumulate, with each layer containing information about oceanographic condition at the time of their deposition. However, the amount and composition of trace metals in the sediment can change as hydrothermal fluids circulate through the sediment and oceanic crust, thereby impacting this geologic record. The goal of this project is to collect samples during a sea-going expedition on the research vessel R/V Polarstern and identify the impact of hydrothermal fluids on the sedimentary environment. The results will advance our knowledge on how hydrothermal vents impact the geochemical signals in sediment deposit and with that their application to reconstruct paleoenvironmental conditions. The project supports the training of a graduate student. During the last few years several expeditions in the Southern Ocean have focused on reconstructing paleoceanographic conditions in this climate-sensitive region of the planet. In this previous work, variations in redox-sensitive element distributions in the sediment were proposed as a valuable tool for unravelling changes in productivity and redox conditions in the water column over time. However, the potential effect of metal-rich sediment on this paleoceanographic record has remained unstudied. The goal of this project is to decipher the potential impact of hydrothermal systems in the Antarctic region onto the sedimentary trace metal signatures frequently applied for paleo redox reconstructions. For this purpose we will join an international expedition on the R/V Polarstern (P119). Hydrothermal deposits and sediments will be recovered using ROV-guided push cores and piston cores. The sedimentary signal will be compared with the trace metal signal in the hydrothermal fluids from two vent sites and background pelagic opal-rich sediment typical for this area. For this purpose, sulfur, iron and manganese phases and selected trace metals will be analyzed in the solid phase and pore waters. Samples will be analyzed for selected constituents onboard the ship. All other analyses will be carried out at home institutes and samples will be prepared and stored accordingly. The data will enhance our understanding of the alteration of primary proxy-signals and the potential impact of hydrothermal fluids on these proxies and could thus be crucial for its application as redox proxy for sites in vicinity to hydrothermal input. Additionally, the results will complement parallel planned research at this location aimed at understanding the role of hydrothermal vents on faunal composition and microbial processes in these extreme environments. 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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/213073
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Natascha Riedinger .Collaborative Research: Interpreting the record of Antarctic sediment influenced by metal-rich hydrothermal deposits from their accumulation through early diagenesis and burial.2019.