Calcium carbonate and trace element composition of ODP Leg 182 sites

An intensive geochemical investigation was conducted on carbonate sediments recovered during Ocean Drilling Program Leg 182. Four trace elements in 635 sediment samples from Sites 1126-1132 on the Great Australian Bight were examined by atomic absorption spectrometry on the acid-soluble fraction. Downhole profiles of these elements exhibit complicated fluctuations throughout the late Eocene to Pleistocene, principally because of the variations in the acid-soluble fraction. The purpose of this study is to present initial results on the geochemical composition of Cenozoic cool-water carbonates as a basis for a future detailed investigation to determine the paleoenvironment of a carbonate-dominated continental margin during the evolution of the Southern Ocean.本研究针对大洋钻探计划（Ocean Drilling Program）第182航次回收的碳酸盐沉积物，开展了系统性地球化学调查。研究对澳大利亚大湾（Great Australian Bight）海域1126至1132号站位的635个沉积物样品中的4种微量元素，采用原子吸收光谱法（atomic absorption spectrometry）对其酸溶组分（acid-soluble fraction）进行了检测分析。上述微量元素的钻孔剖面在晚始新世至更新世时段内呈现出复杂的波动特征，该波动主要源于酸溶组分的含量变化。本研究旨在公开新生代冷水碳酸盐岩的地球化学组成初步研究成果，为后续开展详细调查以阐明南大洋演化过程中以碳酸盐岩为主的大陆边缘古环境提供研究基础。