舟山北部海域海底第四系淡水资源赋存潜力

摘要

为了解东海舟山北部海域海底第四系淡水资源赋存情况,本文在系统分析舟山北部海域地质钻孔和单道地震资料基础上,分析了研究海域海底第四纪地层结构与沉积环境,阐述了研究海域海底松散沉积物分布规律,探讨了上海陆地地区早更新世中、晚期和早期古河道在研究海域的延伸和分布状况,分析了研究海域海底第四系含水层赋存状况.研究海域第四系可供开发利用的主要含水层为早更新世中、晚期的第四承压含水层(Ⅳ)和早更新世早期的第五承压含水层(Ⅴ);第四承压含水层古河道分布区富水性最佳,含水层顶部发育厚层黏性土隔水层区域赋存淡水资源的可能性很大,含水层开发利用潜力可分为开发前景良好A区、开发前景较好B区和开发前景一般C区3类;第五承压含水层在古河道分布区富水性强,具有很好的淡水赋存潜力和良好的开发利用前景.%To comprehend occurrence potential condition of submarine Quaternary freshwater resources in north Zhoushan sea area,Quaternary stratigraphic texture and sedimentary environment are analyzed based on drilling cores and high-resolution single-channel seismic profiles.Regularities of distribution of submarine loose sediment are elaborated.Extension and distribution of paleo-channels in middle and late Early-Pleistocene and early Early-Pleistocene form Shanghai land area and occurrence status of submarine Quaternary aquifer in the study sea area are discussed.The main exploitable Quaternary aquifers are the 4th confined aquifer in middle and late Early-Pleisto-cene and the 5th confined aquifer in early Early-Pleistocene.The water-abundance in the area of paleo-channels in the 4th confined aquifer is best,the confined aquifer with thick upper clay confining layer may be prone to reser-ving freshwater resources.The exploitable potential is classified into three types:better development prospect (type A),good development prospect(type B)and general development prospect(type C).The water-abundance in the area of paleo-channel in the 5th confined aquifer is also good,in which the reserving capacity and prospect of development and utilization are favorable.