Chemical composition of sediments from DSDP Hole 149

The diagenesis and geochemical evolution of deep-sea sediments are controlled by the interaction between sediments and their associated pore waters. With increasing depth, the pore water of Hole 149 (DSDP) exhibits a strong depletion in Mg and a corresponding enrichment in Ca, while the alkalinity remains relatively constant. Dissolved SiO2 is nearly constant in the upper 100 m of sediment, but is highly enriched in the deepest pore waters. The pore waters exhibit a depletion in K with increasing depth, and O18/O16 pore water ratios also decrease. […]深海沉积物的成岩作用与地球化学演化，受控于沉积物与其伴生孔隙水之间的相互作用。随着埋藏深度增加，深海钻探计划（Deep Sea Drilling Project, DSDP）149钻孔的孔隙水呈现出显著的镁（Mg）亏损与对应的钙（Ca）富集，而碱度则维持相对稳定。溶解态二氧化硅（SiO₂）在沉积物上部100米范围内近乎恒定，但在最深部孔隙水中发生强烈富集。孔隙水中的钾（K）含量随深度增加而降低，孔隙水的氧18/氧16（O¹⁸/O¹⁶）同位素比值同样呈下降趋势。[…]