太平洋海山富钴结壳铂族元素(PGE)和OS同位素地球化学及....docVIP

太平洋海山富钴结壳铂族元素（PGE）和Os同位素地球化学及其成因意义( 孙晓明1,2 薛婷1何高文1,3张美1 王生伟1 陆红锋1,3 SUN XiaoMing1,2, XUE Ting1, HE Gaowen1,3, ZHANG Mei1, WANG ShengWei1, LU HongFeng1,3 1中山大学地球科学系, 广州 510275 2中国科学院广州地球化学研究所南海海洋研究所边缘海地质重点实验室, 广州 510640 3国土资源部广州海洋地质调查局, 广州510760 1. Department of Earth Sciences, Sun Yat-sen University, Guangzhou 510275, P.R.China 2. Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510640, P.R.China 3. Guangzhou Marine Geological Survey, The Ministry of Land and Resoures, Guangzhou 510760, P.R.China Sun XM, Xue T, He GW, Zhang M, Shi GY, Wang SW and Lu HF. 2006. Platinum group elements(PGE) and Os isotopic geochemistry of ferromanganese crusts from Pacific Ocean seamounts and their constraints on genesis. Acta Petrologica Sinica, Abstract Platinum group elements (PGE), Au contents and Os isotopic compositions in ferromanganese crusts and their basaltic substrates from the central and west Pacific Ocean were analyzed. The results show that their PGE and Au contents are quite high and greatly varied, the ∑PGE is (70.09~629.26)×10－9 and the total Au is (0.60~26900)×10－9 respectively. In the three-layered (outer, porous and compact layers) crusts, the ∑PGE contents of porous ((339.37~545.82 ) ×10－9) and compact ((280.09~629.26) ×10－9) layers are significantly higher than the outer ((70.09 ~ 133.27) ×10－9) layers. The single-layered crusts are also enriched in PGE(∑PGE=(83.94~479.75)×10-9), and their Au contents are usually higher than the three-layered ones. In addation, ∑PGE and Au contents of ferromanganese crusts are much higher than that in the nodules (∑PGE=(101.57~155.83) ×10-9, Au=(1~4) ×10-9). Different sedimentary water depths and oxygen fugacity of the ambient sea water of the crust and nodules may be the major reason for their different PGE and Au contents. ∑PGE and Pt are positively correlated with Mn % but inversely correlated with Fe %, which is just