Neodymium isotopes distribution and transport in the central North Pacific deep water  

作　　者：EN TianYu LING HongFei HU Rong 

机构地区：[1]State Key Laboratory for Mineral Deposits Research,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Science Bulletin》2011年第21期2243-2250,共8页

基　　金：supported by the Chinese Association for Research of Oceanic Mineral Resources (DY-115-01-2-2);the Program of the Ministry of Education of China

摘　　要：Radiogenic Neodymium (Nd) isotopes in the central North Pacific deep water have been generally interpreted as reflecting Pacific arcs input according to previous studies,while little is known about the specific path and mode of radiogenic Nd from these arcs to deep water.In this study,Nd isotopic data from surface scrapings of 17 Fe-Mn crusts from the central North Pacific deep water (around 20°N) have been reported.Based on these data together with recently published data on dissolved Nd isotopes in seawater for this region,we propose that radiogenic Nd isotopes in North Pacific Intermediate Water (NPIW 300-800 m) from the western Pacific margin is an important source for the central North Pacific deep water,while the surface water of this area has little influence on dominating deep water Nd isotopes.Such a view emphasizes the role of vertical mixing and advection of the marginal ocean currents in balancing Nd isotopes in central North Pacific deep water,and helps to understand oceanic Nd cycling.Moreover,the values of Nd from surface scrapings of Fe-Mn crusts are relatively homogenous,with an average value of about-3.4,which is higher than that of modern seawater (～-3.9).This difference over short time scales reflects the quick evolution of Nd isotopes in central North Pacific deep water.Radiogenic Neodymium （Nd） isotopes in the central North Pacific deep water have been generally interpreted as reflecting Pacific arcs input according to previous studies,while little is known about the specific path and mode of radiogenic Nd from these arcs to deep water.In this study,Nd isotopic data from surface scrapings of 17 Fe-Mn crusts from the central North Pacific deep water （around 20°N） have been reported.Based on these data together with recently published data on dissolved Nd isotopes in seawater for this region,we propose that radiogenic Nd isotopes in North Pacific Intermediate Water （NPIW 300-800 m） from the western Pacific margin is an important source for the central North Pacific deep water,while the surface water of this area has little influence on dominating deep water Nd isotopes.Such a view emphasizes the role of vertical mixing and advection of the marginal ocean currents in balancing Nd isotopes in central North Pacific deep water,and helps to understand oceanic Nd cycling.Moreover,the values of Nd from surface scrapings of Fe-Mn crusts are relatively homogenous,with an average value of about-3.4,which is higher than that of modern seawater （～-3.9）.This difference over short time scales reflects the quick evolution of Nd isotopes in central North Pacific deep water.

关 键 词：太平洋中部 同位素分布 深水 ND同位素 钕 运输 铁锰结壳 同位素平衡 

分 类 号：P734[天文地球—海洋化学]