渤海北部海域碎屑矿物组成特征研究

Detrital mineral composition features of the northern Bohai Sea

对采集自渤海北部海域的23个表层沉积物样品进行碎屑矿物鉴定,以探讨研究区矿物组成特征及影响因素。结果表明:采样区碎屑矿物平均含量为17.1%,其中轻矿物9种,平均含量为96.77%;重矿物33种,平均含量为3.23%。Q型聚类方法分析结果表明,由于构造块体的基岩差异,研究区沿东-西方向可分为两个矿物组合区,在风化搬运规律、蚀源区等差异影响下又可将其细分成四个矿物组合亚区。研究发现,影响渤海北部海域表层沉积环境形成的主要因素是物源,次要因素是水动力,其解释贡献率分别为41.91%和22.74%。

A total of 23 surface sediment samples were collected from the northern Bohai Sea,their detrital mineral assemblages and distribution characteristics as indicators of provenance and dispersal pattern in surface sediments were analyzed. Results showed that the average percentage composition of the detrital mineral is 17. 1%,including 9 species of light mineral（ 96. 77% on average） and 33 species of heavy mineral（ 3. 23% on average）. By using cluster method of Q type,it is showed that the northern Bohai Sea could be divided into two regional mineral assemblage zones along the east-west direction,due to the bedrock differences between two tectonic blocks,and further divided into 4 mineral assemblage zones by laws of watershed erosion source area differences and weathering handling. Provenance factor influence accounts for 41. 91% in total,while tide,ocean currents,and submarine topography factors account for 37. 46%. Assemblages and distributions pattern of detrital mineral in the northern Bohai Sea are mainly controlled by provenances,and also affected by hydrody namic and grain density.