caa a22 4500 445300159 CHVBK 20180317142554.0 cr unu---uuuuu 170323e20100301xx s 000 0 eng 10.1007/s11430-010-0018-y doi (NATIONALLICENCE)springer-10.1007/s11430-010-0018-y Discovery of native aluminum and its possible origin from prospective gas hydrate areas in the South China Sea [Elektronische Daten] [Zhong Chen, ChiYue Huang, BiHao Wu, MeiXun Zhao, Wen Yan] Aluminum is an active amphoteric metal element, but native aluminum (Al°) can be formed and preserved in special conditions so that its occurrence has unique geological significance. In this paper, the coarse fractions (> 63 μm) of 269 samples of surface sediments and of 165 sediment samples in four cores from the South China Sea (SCS) were picked out and analyzed. Al° particles were found in only five surface samples and three samples in two sedimentary cores. The particles are grayish or silver white in color with a strongly metallic luster and high plasticity, and they occur as irregular plats, elongated shapes and spherules with botryoidal structures. The identified Al° particles belong to cubical system, Fm3m space group with a varying from 4.028×10−1 nm to 4.059×10−1 nm. Their chemical compositions consist mainly of Al (95.07%-99.84%) and minor amounts of Si, Fe, Ti, S, Zn, Mg, Ca and trace amounts of K, Na, Cu, Co, P and Mn. Our results show that the identified Al° is authigenic, formed in situ in the prospective areas of gas hydrates, and that it is an unreported type of Al° occurrence. A possible mechanism of Al° formation is proposed: under the strongly reducing micro environments at cold seeps, dissolved Al3+ in sediments is reduced to its metallic state by the strongly reducing agent of H2 through microbial processes and enzyme action. As a result, the Al° particles from the prospective gas hydrate areas in the SCS are the special products, representing the first report on Al° from the sediments at cold seeps. The proposed mechanism provides a theoretical basis for further studies on the special biogeochemical processes at cold seeps. Science China Press and Springer-Verlag Berlin Heidelberg, 2010 native aluminum nationallicence cold seep nationallicence gas hydrate nationallicence reducing environment nationallicence South China Sea nationallicence Chen Zhong Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 510301, Guangzhou, China aut Huang ChiYue Department of Earth Sciences, Cheng Kung University, 701, Tainan, China aut Wu BiHao Institute of Mineral Resources, Chinese Academy of Geological Sciences, 100037, Beijing, China aut Zhao MeiXun Key Laboratory of Marine Chemistry Theory and Technology of the Ministry of Education, Ocean University of China, 266100, Qingdao, China aut Yan Wen Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 510301, Guangzhou, China aut Science China Earth Sciences SP Science China Press 53/3(2010-03-01), 335-344 1674-7313 53:3<335 2010 53 11430 https://doi.org/10.1007/s11430-010-0018-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11430-010-0018-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Zhong Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 510301, Guangzhou, China aut NATIONALLICENCE 700 1- Huang ChiYue Department of Earth Sciences, Cheng Kung University, 701, Tainan, China aut NATIONALLICENCE 700 1- Wu BiHao Institute of Mineral Resources, Chinese Academy of Geological Sciences, 100037, Beijing, China aut NATIONALLICENCE 700 1- Zhao MeiXun Key Laboratory of Marine Chemistry Theory and Technology of the Ministry of Education, Ocean University of China, 266100, Qingdao, China aut NATIONALLICENCE 700 1- Yan Wen Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 510301, Guangzhou, China aut NATIONALLICENCE 773 0- Science China Earth Sciences SP Science China Press 53/3(2010-03-01), 335-344 1674-7313 53:3<335 2010 53 11430 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer