摘要
本文收集了48组世界大洋各种沉积环境锰结核化学组成和生长速率数据并计算了它们的铁锰通量;讨论了不同环境的锰结核的铁锰含量之间的关系,以及锰通量与铁通量、Mn/Fe比的相关性;导出了由锰结核锰铁含量计算生长速率的经验关系;从本质上揭示了锰结核化学组成、生长速率与沉积环境的内在联系,为探讨锰结核形成机理提供了有力的依据.
48 data sets on the major chemical compositions (Mn and Fe concentrations) and growth rates of manganese nodules from different sedimentary environments of the oceans have been collected and their fluxes of manganese and iron have been calculated. It has been shown that although the chemical compositions and growth rates of manganese nodules from different areas of the oceans are largely different (Mn: 11.3-44.9%; Fe: 0.724-20.5%; growth rates: 0.80-200mm / 106yr) , there are small differences in Fe fluxes (10- 102mg Fe / cm2 \\\ 106yr at most) but large one in Mn fluxes (in range of 10 to 104mg Mn / cm2 \\\ 106yr), reflecting that the diagenetic reactivity of manganese is much stronger than that of iron in marine environments.
It has been demonstrated by statistical analyses the (1) the concentrations of manganese and iron of individual nodules are correlative positively for the nodules with the Mn / Fe ratios of ~ 1 but negatively for those with high Mn/ Fe ratios becauce of different contribution of diagenetic manganese; (2) The relationships of Mn fluxes to Fe fluxes or Mn / Fe ratios of the manganese nodules are dependent on classification of sedimentary environments, but the changes of Mn fluxes and Mn/ Fe ratios caused only by diagenetic processes are linearly correlative, independent on the classification of sedimentary environments. The following equation, derived from the correlation of Mn fluxes to Mn / Fe ratios of manganese modules, can be used to predict the growth rates from the Mn concentrations and Mn/ Fe ratios of the nodules and reveal the importance of sedimentary environments to the chemical composition and growth rate of manganese nodules:
S(mm/106yr) = [52.0(Mn/ Fe - 0.60)1.25 + 10] / [Mn]
出处
《沉积学报》
CAS
CSCD
北大核心
1989年第4期77-84,共8页
Acta Sedimentologica Sinica
