Chemistry of pore water and solids, formation factors and salt-corrected porosities of DSDP Site 68-503

Recent discoveries relating to the circulation of fluids within the oceanic crust include the finding of both important fluxes of elements and isotopes into the oceans by ridge-crest hydrothermal convection and important fluxes of heat out of the oceanic crust by convection at ridge crests and at some distance from ridge crests. In the present chapter, I present isotopic, chemical, and physical data from sediments and pore waters of Deep Sea Drilling Project (DSDP) Holes 503A and 503B. These results are modeled in terms of pore-water diffusion, advection, and production to ascertain the relative contribution of these processes at this location, 7.5 m.y. removed from ridge-crest hydrothermal activity. The observations made here contribute to the understanding of chemical and heat transport in oceanic crust of moderate age.

关于洋壳内部流体循环的最新研究发现表明，脊轴热液对流可向海洋输入大量元素与同位素通量，同时在脊轴区域及远离脊轴的位置，通过对流作用从洋壳向外释放大量热通量。在本章中，笔者整理了深海钻探计划（Deep Sea Drilling Project, DSDP）503A与503B钻孔的沉积物及孔隙水的同位素、化学与物理数据。本研究基于孔隙水扩散、平流及生成作用对上述结果进行建模，以明确该区域（距今750万年且远离脊轴热液活动）内各过程的相对贡献。本次研究的观测结果有助于加深对中等年代洋壳内化学物质与热传输过程的理解。