摘要
用碱熔法新测得Jade热液区 7件海底块状硫化物样品的锇含量及其同位素组成 ,1 87 Os/1 86Os比值在 2 2 0 5— 6 462之间 ,均值为 4 31 4,高于地幔端员 ,而低于海洋沉积物和海水端员 ,表明该区块状硫化物中锇是深部来源锇与海水和 /或沉积物混合的产物。结合该区块状硫化物样品的REE、硫和铅同位素组成特征 ,进一步揭示出海水、长英质火山岩、沉积物和深部地幔源是形成Jade区块状硫化物的物源。
In the Okinawa Trough,the rare earth elements,sulfur and lead isotopic compositions of seafloor massive sulfides from the Jade hydrothermal have been studied in order to understand their sources. Although we know the source of rare earth elements,sulfur and lead in the seafloor massive sulfides,we do not know the sources of the major metal materials of forming seafloor massive sulfides,for example,iron,copper,zinc,etc.; it is still a disputing question on the material sources of forming seafloor massive sulfides. Due to the material sources of forming seafloor massive sulfides from the Jade hydrothermal field is a key question for understanding the formation mechanism of seafloor massive sulfides and the evolution of seafloor hydrothermal activity in the Okinawa Trough. This paper will report the analytical results of osmium isotopic compositions of seafloor massive sulfides from the Jade hydrothermal field,study the characteristics of osmium isotopic compositions of seafloor massive sulfides,and discuss the material sources of hydrothermal ore-forming in the Jade hydrothermal field. For measuring the osmium isotopic compositions of seafloor massive sulfides from the Jade hydrothermal field,the whole rock samples of massive sulfides were rubbed in an agate mortar,adding the suitable Na 2O 2 and NaOH to the powder samples of 0.5—1g,then the samples were heated to 700℃ for melting,using the hot-water to distill the melting samples,adding the acetone to the solution of 4/5 volume for extracting the rhenium,adding CrO 3 and H 2SO 4 to the solution of 1/5 volume for acidifying. The OsO 4 from the solution were absorbed by HBr,then the rhenium contents and osmium isotopic compositions of samples were measured by the MAT-262 mass spectrograph. New data on the osmium isotopic compositions,the rhenium and osmium contents of seven seafloor massive sulfide samples from the Jade hydrothermal field have been obtained. The rhenium content range of massive sulfide samples is from 3.505×10 -9to 154.900×10 -9,
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2003年第4期407-413,共7页
Oceanologia Et Limnologia Sinica
基金
国家重点基础研究发展规划项目
G2 0 0 0 0 4670 1号
国家自然科学基金资助项目
40 1 760 2 0号。
