The High Temperature Titration of Amorphous Silica

建立了一种新的测定海洋沉积物中无定形二氧化硅的新方法。它是基于无定形二氧化硅与添加碳酸钙的高温滴定反应：SiO_2+CaCO_3-CaSiO_3+CO_2。拟议的研究将沿着三条线进行：1.该方法的进一步发展。初步的热解实验在500oC下进行了三天。随后的工作是在700oC下进行一小时。这些新的条件需要重复许多实验来确定最佳温度和时间，以及反应对最佳条件的矿物学、水含量等的依赖关系。2.重估海洋硅石预算。初步工作表明，钙质软泥和大陆架沉积物是比之前认为的更重要的下沉。3.使用产品二氧化碳的&amp；18O作为无定形二氧化硅及其沉积的古海洋的&amp；18O的量度。//

A new and novel technique will be developed for the determination of amorphous silica in marine sediments. It is based on the high temperature titration of amorphous silica with added calcium carbonate according to the reaction: SiO2 + CaCO3 ----- CaSiiO3 + CO2. The proposed research will proceed along three lines: 1. Further development of the method. Preliminary pyrolysis experiments were done at 500oC for three days. Subsequent work was at 700oC for one hour. These new conditions necessitate the repetition of many experiments to determine the optimum temperature and time and the dependence of the reaction on mineralogy, water content etc. for the optimum conditions. 2. Revaluation of the marine silica budget. Preliminary work indicates that calcareous oozes and continental shelf sediments are much more important sinks than previously believed. 3. The use of the &18O of the product CO2 as a measure of the &18O of amorphous silica and the paleocean from which it was deposited. //