摘要
根据广西北海近岸表层沉积物取样测试结果,通过统计方法分析了研究区表层沉积物粒度特征、重金属Cr分布及其相互关系。结果表明,Cr含量为5.2×10^(-6)~66.7×10^(-6),在不同沉积物显示出不同统计特征;由于波浪淘选作用,表层沉积物砂分布最为广泛,粒级主要在~0.5mm到~0.25mm之间;砂由于颗粒较粗,其粒级与Cr关系较为分散,但总体上仍然存在着线性关系,且随着粒级变细相关性提高。黏土质砂的粒级与Cr线性关系明显改善,吸附粒级拐点在~0.125mm至~0.063mm之间;Cr含量与分选和平均粒径为线性关系,与偏态、峰态为聚类关系,并划分出五类聚类类型;有机质随沉积物颗粒变细而升高,变化范围为0.02%~1.29%,在黏土质砂中与Cr为显著线性正相关,且高、低值分段拟合关系稳定。Cr/Org比值变化很大,在(43~419)×10^(-6)/%之间,高、低值段Cr与有机质关系均表现稳定。长石/石英比值为0.03~0.08表明化学风化尚在初级阶段,Cr与该比值的关系尚不明显;以最小二乘法线性拟合参数|k|·R^2来综合表示沉积物组分、成分和粒级对Cr之影响性,砂沉积物中以砂组分影响力最大,砂质黏土中,砂组分含量大为降低,有机质权重最高。
Based on geological test data in Beihai nearshore waters, the relationship between heavy metalCr in surficial sediments in survey area and sediment grain sizes is analyzed. The results showed thatsand is widely distributed because of wave control with main grain sizes from-0.5mm to-0.25mm; Crconcentration is 5.2×10^-6 -66. 7 ×10^-6 and has different statistical features in different sediments.Generally, there are linear trends between sand＇s grain sizes and Cr, and the linearity becomes better inclay sand and the slope k transition falls into the range of -0. 125mm to -0. 063mm; there are also lin-ear relationships between sorting and mean size, and cluster relationships between Cr and skew andkurtosis. Organic matter ranges from 0.02%-1.29% and have significant positive correlation with Crespecially in clay sand. Cr/Orgis 43 10 6/%-419 10^-6/% revealing different roles of organic matterson Cr＇s accumulation. Linear fitness parameter calculation reveals that sand composition is the controlfactor on Cr＇s accumulation in sand sediment and so does organic matters in sandy clay.
出处
《海洋湖沼通报》
CSCD
北大核心
2014年第2期169-176,共8页
Transactions of Oceanology and Limnology
基金
中国地质调查局"我国重点海岸带滨海环境地质调查与评价"(编号1212010611403)
关键词
近岸
沉积物
铬
分布
near shore
sediment
Chromium
distribution
