| 摘要: |
| 于1986－1988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一第四纪。同时对老、新世代结核的矿物成份和化学成份进行分析，并得出，老世代结核比新世代结核含钡镁锰矿多，富Mn，Ni，Cu，Zn，Mg，而贫Fe，Co，Pb。通过引证与讨论初步得出，前一世代结核是在沉积间断时期受南极底层流的冲蚀而破碎，南极底层流为新世代结核提供物质并造成有利的生长环境；锰结核是在气候比较寒冷、沉积速率比较低的条件下，从盐度相对较高的海水或软泥水中析出Fe，Mn水合物聚结而成结核的。 |
| 关键词: 锰结核 锰结核的世代 太平洋 古海洋事件 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助，49272090号 |
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| GENERATIONS OF MANGANESE NODULES FROM THE CENTRAL PACIFIC OCEAN AND THEIR RELATIONSHIP WITH PALAEO-OCEAN EVENT |
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Shan Lianfang
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Institute of Marine Geology, Ministry of Ceology and Mineral Resources,Qingdao 266071
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| Abstract: |
| 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 generally 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 and chemical compositions of the old and young nodules showed the former contained more todorokite, and is richer in Mn, Ni, Cu, Zn, Mg, but poorer in Fe, Co, Pb than later. A preliminary conclusion is that scouring by Antarctic Bottom Water current during the hiatus, resulting in breaking and abrasion of the old generation nodules, probably provided the material and favorable growing environment for the new generation of nodules which formed probably when climate was colder, and sedimentation rate was slower and salinity higher in bottom water where pore water Fe-Mn hydroxides separated out and accumulated to anganese nodules. |
| Key words: Manganese nodule, Generationof manganese nodule, Pacific Ocean, Palaeo-ocean event |
