Minor element geochemistry of Lake Michigan ferromanganese nodules

Samples of ferromanganese nodules from several localities in Lake Michigan have been analyzed for their minor element content utilizing neutron activation techniques. The thorium and uranium levels in Lake Michigan nodules exhibit marked dissimilarities with marine nodules. The radium content of these freshwater nodules is substantially higher than the reported marine values.针对采自密歇根湖多个采样点位的铁锰结核（ferromanganese nodules）样本，研究人员借助中子活化技术（neutron activation techniques）对其微量元素含量进行了分析测定。密歇根湖铁锰结核中的钍（thorium）与铀（uranium）含量，与海洋铁锰结核的对应指标存在显著差异。这类淡水铁锰结核的镭（radium）含量，显著高于已公开报道的海洋铁锰结核的镭含量数值。