【摘要】 <正>海底沉积物的化学组成复杂,主要成份变化很大。例如,随着海区的不同,某些海底沉积物中的碳酸钙和二氧化硅的含量在0.1—95%之间,变化之大,由此可见。 随着海底地貌的不同,各海区的沉积物类型也不一样。根据它们的化学组成,大致可分为三种类型:更多还原

【Abstract】 A method has been developed for simultaneous semi quantitative spectro-graphic determination of 6 rock-forming elements(Al,Ca,Mg, Fe, Mn, Ti)and 80 and odd trace elements in the bottom sediments from the South China Sea.Samples of the sediments were classified into 8 types, namely, silicate, aluminium-silicon clay and carbonate types,according to their chemical compositions.In order to analyse the samples, 3 sets of standard sample series, closely corresponding to the 3 sample types were prepared separately . Samples were placed into the cavity of the lower cup-electrode. Excitation source was direct current arc (D.C .). Each loaded eletrode was exposed twice and 2 spectra were obtained. The first spectrum was exposed for 45 seconds and current intensity was 6A,and the second one 30 seconds at 12A at first, and then went on to be exposed,while the current intensity was increased to 16A,until the samples were burnt up and this spectrum was taken. The measurement range of the rock-forming elements was 0.1-10%,that of the trace elements was 0.001-0.1%. A comparison between the result of this method to measure the rock-forming elements and the result obtained by means of chemical analyses has been made. Precision of the measurements is within the tolerance limit of semi quantitative spectrographic analyses and can meet the requirements of marine geological investigations.更多还原