气候变化领域集成服务门户(CCPortal): Sediment geochemistry PASOM research cruise (2009) - Murray Ridge region, northern Arabian Sea

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.830824
	Sediment geochemistry PASOM research cruise (2009) - Murray Ridge region, northern Arabian Sea
	Kraal; Peter; Slomp; Caroline P; Reed; Dan C; Reichart; Gert-Jan; Poulton; Simon W
发布日期	2012-03-21
数据集类型	dataset
英文简介	In this study, we investigate phosphorus (P) and iron (Fe) cycling in sediments along a depth transect from within to well below the oxygen minimum zone (OMZ) in the northern Arabian Sea (Murray Ridge). Pore-water and solid-phase analyses show that authigenic formation of calcium phosphate minerals (Ca-P) is largely restricted to where the OMZ intersects the seafloor topography, likely due to higher depositional fluxes of reactive P. Nonetheless, increased ratios of organic carbon to organic P (Corg/Porg) and to total reactive P (Corg/Preactive) in surface sediments indicate that the overall burial efficiency of P relative to Corg decreases under the low bottom water oxygen concentrations (BWO) in the OMZ. The relatively constant Fe/Al ratio in surface sediments along the depth transect suggest that corresponding changes in Fe burial are limited. Sedimentary pyrite contents are low throughout the ~25 cm sediment cores at most stations, as commonly observed in the Arabian Sea OMZ. However, pyrite is an important sink for reactive Fe at one station in the OMZ. A reactive transport model (RTM) was applied to quantitatively investigate P and Fe diagenesis at an intermediate station at the lower boundary of the OMZ (bottom water O2: ~14 µmol/L). The RTM results contrast with earlier findings in showing that Fe redox cycling can control authigenic apatite formation and P burial in Arabian Sea sediment. In addition, results suggest that a large fraction of the sedimentary Ca-P is not authigenic, but is instead deposited from the water column and buried. Dust is likely a major source of this Ca-P. Inclusion of the unreactive Ca-P pool in the Corg/P ratio leads to an overestimation of the burial efficiency of reactive P relative to Corg along the depth transect. Moreover, the unreactive Ca-P accounts for ~85% of total Ca-P burial. In general, our results reveal large differences in P and Fe chemistry between stations in the OMZ, indicating dynamic sedimentary conditions under these oxygen-depleted waters.
空间范围	Median Latitude: 22.283666 * Median Longitude: 63.591000 * South-bound Latitude: 21.926670 * West-bound Longitude: 63.075000 * North-bound Latitude: 22.565000 * East-bound Longitude: 64.063330
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/217524
推荐引用方式 GB/T 7714	Kraal,Peter,Slomp,et al. Sediment geochemistry PASOM research cruise (2009) - Murray Ridge region, northern Arabian Sea.2012-03-21.https://doi.org/10.1594/PANGAEA.830824.