渤海湾北部底质沉积物中黏土矿物组成与物源研究

Characteristics and Provenance of Clay Mineral Assemblage of Sediments from the Northern Part of the Bohai Bay

采用X射线衍射物相分析,对渤海湾北部166个表层沉积物样品和A435柱状样中的23个沉积物样品的主要黏土矿物含量组成进行分析。研究结果表明:渤海湾表层沉积物黏土矿物中伊利石(53.0%)含量最高,其次为蒙脱石(27.9%)、绿泥石(9.9%)和高岭石(9.2%),黏土矿物组合为伊利石-蒙脱石-绿泥石-高岭石型。渤海湾北部表层沉积物可分成3个沉积区,分别代表不同的沉积物来源:北部沿岸为滦河-海河物源区;中部和东部为黄河-海河物源区;西部沿岸为海河物源区。渤海湾北部表层沉积物黏土矿物分布和组合特征显示了渤海湾环流对海河、黄河和滦河来源物质的搬运和扩散作用。A435柱状样各黏土矿物含量在100cm以上层段具有很大的波动性,推测主要为黄河在1048—1128年和1128—1855年的改道事件的影响。

The clay minerals of 166 surface sediments and 23 sediments of sediment core A435 from the northern part of the Bohai bay were analyzed with the X-ray diffraction method.The results showed that Illite,averaging 53.0%,was the dominant clay mineral in the surface sediments of the northern part of the Bohai bay,followed in concentration by smectite（27.9%）,chlorite（9.9%） and kaolinite（9.2%）.The illite-smectite-chlorite-kaolinite type was the main clay mineral assemblage of the surface sediments.The surface sediments could be divided into three sedimentary provinces： the northern coastwise from Luanhe river and Haihe river,the middle region from the Yellow river and Haihe river and the other area from the Haihe river.The assemblage and distribution of the clay mineral in surface sediments of the northern Bohai bay were influenced by the source of the rivers and transports of the current.In the sediment core A435,the assemblage of clay mineral varied greatly above the layer of 100 cm.That＇s may be caused by the migration of the Yellow River,which discharged into the Bohai from 1048 to 1128 AD and emptied into the South Yellow Sea from 1128 to 1855 AD.