The magnetite grains from the Changjiang upstream sediments are rich in Ti whereas those from the downstream sediments are poor in most elements, such as Ti, Al, Cr, V, Mg and Mn (mostly lower than 0.15% ).

• 总体上；长江干流上游磁铁矿富Ti；而下游磁铁矿中Ti、Al、Cr、V、Mg和Mn含量低于0.；15%25。