Composition of sedimentary material from the bottom and the area surrounding the Lake Untersee, East Antarctica

This paper presents data on geographic and geologic conditions of modern sedimentation in the Lake Untersee, the largest lake in the East Antarctica. Geochemical and sedimentation data indicate that the leading mechanism supplying aluminosilicate sedimentary material to the surface layer of bottom sediments is seasonal melting of the Anuchin glacier and the mountain glacier on the southeastern part of the valley hosting the lake. Strongly reduced conditions in the lowermost 25 m of the water column in the smaller of two depressions of the lake bottom were favorable for enrichment of the bottom sediments in bacteriogenic organic matter, Mo, Au, and Pd. H2S-contaminated water results to significant enrichment of the sediments only in redox-sensitive elements that are able to migrate in anionic complexes and precipitate (co-precipitate) as sulfides.本论文提供了南极东部最大湖泊——翁泽湖（Lake Untersee）现代沉积作用的地理与地质条件相关数据。地球化学与沉积学数据表明，向湖底表层沉积物供给铝硅酸盐沉积物质的主要机制为阿努钦冰川（Anuchin glacier）以及该湖所在山谷东南部山地冰川的季节性消融。该湖湖底的两个凹陷盆地中，较小凹陷的水柱底层25米范围内存在强还原环境，这有利于底沉积物富集细菌成因有机质、钼（Mo）、金（Au）与钯（Pd）。硫化氢污染水体仅会使沉积物显著富集那些能够以阴离子络合物形式迁移、并以硫化物形式共沉淀的氧化还原敏感元素。