渤海湾唐山港海域表层沉积物粒度和黏土矿物分布特征及其物源指示

通过对取自渤海湾唐山港海域的161个站位的表层沉积物进行粒度和黏土矿物组成及分布特征分析，探讨不同区域沉积物物质来源及其控制因素。研究结果表明，唐山港海域表层沉积物平均粒径（Mz）为1.4～7.7 Φ，主要由粉砂质砂、砂质粉砂以及少量的砂和黏土组成。根据粒度参数特征和端元模型分析，研究区沉积物可以分为3个区和EM1—EM4四个端元：东北部以EM3端元砂和粉砂质砂为主，分选较差、正偏态，沉积环境动力强；中部曹妃甸深槽区以EM4端元砂质粉砂和粉砂质砂为主，分选差、正偏态，沉积环境动力强；南部和北部唐山港附近区域以EM1和EM2端元粉砂为主，分选中等—较差，沉积动力环境较弱。黏土矿物组成主要是伊利石（72%）和蒙脱石（12%），其次是绿泥石（8%）和高岭石（8%）。物源分析表明，渤海湾唐山港海域表层沉积物中细颗粒组分来源主要是黄河-海河混合来源的陆源碎屑物质，研究区东北部和曹妃甸深槽区可能有部分古滦河三角洲粗颗粒物质的加入。渤海环流和潮余流控制着本区细颗粒沉积物主要向南部和唐山港附近运移，粗颗粒物质向东北部和中部曹妃甸区搬运沉积。

Characteristics of grain size and clay mineral distribution of surface sediments and their provenance implication in Tangshan Harbor,Bohai Bay

The grain size and clay composition and distribution of 161 samples taken from surface sediments in the Tangshan Harbor, Bohai Bay were analyzed to explore the provenance and the controlling factors. Results show that the average grain size (Mz) of the surface sediments was from 1.4 ～ 7.7 Φ, and mainly consists of silty sand, sandy silt, and a small amount of sand and clay. According to the characteristics of grain size parameters and end-member modelling analysis, the sediments can be divided into three zones and four end-members (EM1 to EM4). The northeastern part of the area is dominated by EM3 (sand and silty sand), with poor sorting, positive skew, and strong dynamics of depositional environments. The central Caofeidian Deep Trough area is dominated by EM4 (sandy silt and silty sand), with poor sorting, positive skew, and strong dynamics of depositional environments. The southern part and the Tangshan Harbor area is dominated by EM1 and EM2 (silt), with moderate-poor sorting and weak depositional dynamics. The clay minerals are relatively high in illite (72%) and smectite (12%), followed by chlorite (8%) and kaolinite (8%). The provenance analysis shows that the source of surface sediments in Tangshan Harbor is mainly the mixed detrital materials from Yellow River and Haihe River, while the northeastern part of the study area and the Caofeidian Deep Trough may have some coarse-grained materials from the ancient Luanhe Delta. The Bohai Sea circulation and tidal currents control the transport of fine-grained sediments mainly to the south and near Tangshan Harbor, while coarse-grained materials are transported and deposited to the northeastern and central Caofeidian area.