赤道东北太平洋悬浮体物源示踪元素的研究

Characteristics of the elemental source tracers of the suspended particles in the northeastern equatorial Pacific Ocean

2005年7月在赤道东北太平洋的3个测站分层采集了悬浮体水样．利用ICP—MS对悬浮体的元素组成进行了测试，从测试的47种元素中筛选出了钡和铝分别作为悬浮体生源组分和陆源组分的示踪元素．悬浮体中钡含量为0．02～0．19μg／dm^3，其中生源钡含量为0．01～0．13μ／dm^3，铝含量为0．33～18．54μg／dm^3．生源钡和铝元素含量及其比值在水体中的分布特征与悬浮体含量的相对应，分为三段．水体透光层生物作用和近底层底质沉积物再悬浮作用是其在水体表层和近底层显著变化的原因．近底雾状层内生源钡和铝元素含量的比值从水体向底质沉积物中降低，至底质沉积物降到最低，显示出底质沉积物再悬浮对悬浮体组分和含量的影响，可以作为近底雾状层颗粒物质运移的示踪指标．

Water samples for suspended particles in water column were collected at 3 stations in the China Pioneer Area of Multi-metallic Nodules, the northeastern Pacific Ocean in July 2005. The samples of suspended particles were analyzed by ICP-MS, and contents of 47 elements from the particles were obtained. The barium and aluminum were chosen as the biogenic and terrigenous source tracers for the suspended particles, respectively. The barium content ranges from 0.02 to 0.19 μg/dm^3 with the bio-barium content range from 0.01 to 0.13μg/dm^3 , and the aluminum content ranges from 0.33 to 18. 54μg/dm^3. The distribution of the bio-barium and aluminum of suspended particles and their ratio from the surface to the bottom in the water column corresponding to that of the TSM, which can be divided into three parts, was mainly caused by the distribution of biological process in the euphotic layer and the resuspension process of the seafloor sediment in the benthic layer. The decreasing tendency of the ratio of bio-barium to aluminum from marine benthic layer down to the seafloor reveals the evident change of the content and component of the suspended particles caused by the resuspended seafloor sediment in the benthic layer. Thus, their ratio can be regarded as an effective tracer of suspended particles exchange and transport in the benthic nepheloid layer.