印度洋多金属结核地质特征与资源潜力

Geological characteristics and resource potential of polymetallic nodules in Indian Ocean

通过在中印度洋海盆结核区外的印度洋其他海域内收集到的298处多金属结核站位的分布、成分和赋存环境等地质特征,圈定了5处资源潜力区。文章对这些区域内海洋长周期沉积速率、底层水含氧量、底质类型、夏季海面平均生物生产力、底栖宏生物量密度、海底地形地貌特征和海底表层沉积物有机碳含量等数据信息进行加权评估,揭示各区域结核分布密度的高低状况,辅以结核主要有用组分含量的分类,确定了印度洋内各结核区资源潜力的划分标准。笔者认为加斯科因平原结核区为印度洋多金属结核高资源潜力区,马达加斯加海盆结核区和南澳大利亚海盆西部结核区为中等资源潜力区,克洛泽海盆结核区和南澳大利亚海盆东部结核区为低资源潜力区。未来在这些区域内,尤其是加斯科因平原结核区中有希望通过进一步调查研究,精确锁定具有更高资源潜力的次级面积结核勘探区,检验和完善资源潜力评估方法,精细量化揭示这些区域的资源潜力。

Five potential resource areas were delineated based on the distribution,composition and environmental information of 298 polymetallic nodule sites from the Indian Ocean except the Central Indian Ocean Basin nodule field.We made weighted assessments of the long-term sedimentation rates,bottom-water oxygen concentrations,seafloor lithology,summer sea-surface productivity,abundance of benthic megafaunal biomass,bathymetry and total organic carbon in the seafloor sediment from these areas.All above can reveal the distribution abundance of the nodules and determine the criteria for dividing the resource potential area of the polymetallic nodules in the Indian Ocean,which combined with the grade of the valuable metals of the nodules.This study considered the Gascoyne Abyssal Plain nodule field as the best resource potential area,the Madagascar Basin nodule field and the western South Australian Basin nodule field as the moderate resource potential area,the Crozet Basin nodule field and the eastern South Australian Basin nodule field as the lowest resource potential area.In the future,it is expected that the higher potential resource sub-areas of the nodules will be accurately identified in these fields through investigations and studies,especially in the Gascoyne Abyssal Plain nodule field,and the resource potential assessment methods will be tested and improved to reveal the resource potential of these regions precisely and quantificationally.