| We have carried out XRD analyses, sequential extraction procedures and whole-rock analyses for the sediment samples obtained from E53 site near the East Pacific Rise 13°N. We discussed hydrothermal activity records in sediment core according to the mode of occurrence of elements and the process of hydrothermal activity in study area combining with dating data.The sediment core can be divided into three layers, with the upper layer brown, the middle layer yellow and the bottom layer sage green. The XRD results indicate that the primary mineral phase of E53 upper layer is amorphous Fe-oxyhydroxide and Mn-oxides and the main mineral phase of its bottom layer is calcite. According to elements in whole-rock and different phases, we divide major and trace elements into different groups. Fe and Mn mainly concentrate in the ferromanganese oxide phase,and their contents decrease according with whole-rock samples downcore. Al,Ti,Ba mainly concentrate in the residual phase and K,Na,Mg mainly concentrate in the carbonate phase. Ca,Sr also mainly concentrate in the carbonate phase, which have carbonate as their main modes of occurrence. When coming to trace elements, Mo,Co,V,Cu,Zn,Ni,Y,Pb mainly concentrate in ferromanganese oxide and decrease in contents with depth. Th,Sc,Li,Zr mainly concentrate in the residual phase; Cd,U mainly concentrate in the carbonate phase. There are following three characters in mode of occurrence of elements of rare earth elements (REE). Firstly, REEs mostly concentrate in the ferromanganese oxide phase and the contents decrease downcore. Secondly, the secondary modes of occurrence is the carbonate phase, the contents increase downcore and exceed the former at one time. Thirdly, contents are very low and vary little in the redisual phase and the bound to organic phase.Combining with former dating data, we could conclude that the records in E53 sediment core reflect a recent hydrothermal activity which were enhaced but stable recently.
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