Geochemical speciation and spatial distributions of phosphorus in surface sediments from the basin of the Marcus-Wake seamounts in the western Pacific Ocean  

作　　者：Chao Yuan Fansheng Meng Xuying Yao Jianyu Ni 

机构地区：[1]Key Laboratory of Submarine Geosciences,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China

出　　处：《Acta Oceanologica Sinica》2022年第4期80-90,共11页海洋学报（英文版）

基　　金：The China Ocean Mineral Resources Exploration and Development Special Foundation under contract No.DY135-S1-1-08。

摘　　要：The concentrations of five forms of phosphorus(P)including exchangeable or loosely adsorbed P(Ex-P),Febound P(Fe-P),authigenic P(Auth-P),detrital P(Det-P),and organic P(Org-P)from the basin among the Marcus-Wake seamounts(19.4°–24°N,156.5°–161.5°E)in the western Pacific Ocean were quantified using a sequential extraction method(SEDEX)to investigate the distribution and sources of different P species.Concentrations of total P(TP)varied from 14.0μmol/g to 44.1μmol/g,with an average of(32.4±7.7)μmol/g.Inorganic phosphorus,which was the major chemical form of sedimentary P,ranged from 12.6μmol/g to 40.6μmol/g,while the concentration of Org-P varied between 1.38μmol/g and 5.18μmol/g,accounting for 83.4%–93.4%and 6.6%–16.6%of the TP,respectively.The relative proportions of the five P species followed the order of Det-P>Auth-P>Org-P>Fe-P>Ex-P.On average,Det-P was the major P sink resulted from the atmospheric input and accounted for approximately 58.9%±12.4%of the TP.Auth-P and Org-P comprised 22.8%±11.4%and11.5%±3.0%of the TP,respectively,while Fe-P accounted for 5.1%±2.6%.Lastly,Ex-P comprised 1.6%±0.3%of the TP.Org-P exhibited a negative correlation with Fe-P and Auth-P,while Fe-P showed a positive correlation with Auth-P.This indicated that the formation of Fe-P and Auth-P was at the expense of the regeneration or remineralization of Org-P during early diagenesis.High concentrations of Det-P and Auth-P as well as a low ratio of total organic C to reactive P(TOC/Rea-P)suggested that the aeolian input may play a significant role in sedimentary P budget in the study area.Additionally,well-oxygenated bottom water and low sedimentation rate could be responsible for the low TOC/Org-P ratio in the sediment.

关 键 词：phosphorus speciation SEDEX sediments western Pacific Ocean 

分 类 号：P736.41[天文地球—海洋地质]