中文摘要：

为了进一步了解富钴结壳中Ti的元素地球化学特征，对中太平洋M海山一块富钴结壳C5进行元素化学和矿物学分析。结果表明：样品C5具有新老两个生长世代壳层，相对于新壳层，老壳层除含水羟锰矿、非自形FeOOH.xH2O、石英、长石和方解石等矿物外，还含碳氟磷灰石、钡镁锰矿和针铁矿；老壳层中Ti的平均质量分数为0．75％，富集于铁矿物相和碎屑矿物相中，来源于海水和碎屑；新壳层中Ti的平均质量分数为1．92％，主要来自海水中，通过晶格替代过程富集于锰矿物相；另外，Ti的富集也可能受动力过程控制，但Ti的富集通量在生长过程中非恒定，这可能源于其物源多样性；富钻结壳是潜在的海底钛矿资源。

英文摘要：

One cobalt-rich crust C5 from M seamount in Central Pacific Ocean was analyzed mineralogically and chemically to understand the geochemical characters of Ti in cobalt-rich crust. The results show that the cobalt-rich crust C5 shows two growth generations, the lower older section and the upper younger section. The older section contains the carbonate-fluorapatite todorokite and goethite, besides vernadite, amorphous FeOOH.xH2O, quartz, feldspar and calcite, which occur in the younger section. The Ti in the older section has an average mass fraction of 0.75%, which enriches in iron mineral phase and detrital mineral phase and origins from seawater and clastic minerals. In the younger section, the content of Ti is 1.92%, which enriches in manganese mineral phase through lattice-substituting and origins from seawater. Furthermore, dynamic process controls partly the enrichment of Ti in crust. However, the enrichment fluxes of Ti change during the cobalt-rich curst growing, which could be induced by the multiple material sources. The cobalt-rich crust is a potential Ti resource on the seafloor.