太平洋中部锰结核世代及其与古海洋事件的关系

于１９８６－１０９９年由海洋四号调查船的ＨＹ４－８６１,８７１,８８１三个航次采集的锰结核样品中选出３７个以老结核或老结核碎块为核心的结核,进行研究,划分出３个结核世代,并大致确定其生长期：第一世代结核的生长期是在早中新世（〈２０Ｍａ）;第二世代结核形成于早中新世－晚中新世（〉６Ｍａ）;第三世代结核的生长期是在上新世－第四纪。同时对老、新世代结核的矿物成份和化学成份进行成析,并得出,老世代结核比新

GENERATIONS OF MANGANESE NODULES FROM THE CENTRAL PACIFIC OCEAN AND THEIR RELATIONSHIP WITH PALAEO-OCEAN EVENT

Study of 37 manganese nodules obtained by the R/V "Ocean 4" cruises HY4-861, 871, 881 showed they could be divided into three generations delimited gener-ally by their growing period: first generation nodules formed in Early Miocene(<20Ma), second generation formed in Early Miocene-Late Miocene (>6Ma),third generation formed in Pliocene-Quaternary. Comparison of the mineral andchemical compositions of the old and young nodules showed the former containedmore todorokite, and is richer in Mn, Ni, Cu, Zn, Mg, but poorer in Fe, Co, Pbthan later.A preliminary conclusiOn is that scouring by Antarctic Bottom Watercurrent during the hiatus, resulting in breaking and abrasion of the old generationnodules, probably provided the material and favorable growing environment for thenew generation of nodules which formed probably when climate was colder, and se-dimentation rate was slower and salinity higher in bottom water where pore waterFe-Mn hydroxides separated out and accumulated to manganese nodules.