| Depositional records in muddy area is the important information carrier of themarine environmental evolution in Holocene. Through accurate interpretation of shallowstratigraphic section data from "1:250000Qingdao division of marine geologicalsurvey", a small mud deposition area was found in the southern coastal waters ofShandong Peninsula. It mainly be distributed in coastal waters from north of QingdaoLaoshan to mouth of Rushan, the overall parallels to the coastline and with bandeddistribution. The mud area gradual thinning from the shore to the sea, and equalthickness parallel to the shoreline, the deposition centers are located in Aoshan Bay.AMS14C dating results show that the shale region was formed in the Holocene. Byanalyzing grain size, clay minerals, detrital mineral and geochemical elements of76surface sediments and3core sediments collected from the mud area, and contrastingcomposition material of main rivers run into the sea (Dagu, Wulong, Rushan rivers),then combining with granularity, element geochemistry, clay minerals, detrital mineralsand AMS14C dating data of shallow drilling (QDQZ03), sedimentary characteristics andsource conditions of muddy sedimentary area in southern coastal waters of ShandongPeninsula were comprehensively analyzed. Results were showed as follows:(1) According to Folk classification, types of sediment are silt and sandy silt, siltaccounted for70%and sandy silt accounted for30%. QDZ02, QDZ14, QDZ18coresgranularity parameter analysis were showed as follows: from west to east, the particlesof sediment are from coarse to fine, sand content in the sediments becomes fewer, whilefine-grained sediments increases. From north to south, the fine-grained sedimentsthicker and sand content in the sediment becomes larger, fine-grained sedimentsdecreases. QDQZ03in the study area reveals that the entire drilling shallow (0~8.63m)component sediment is less of sand content, shallow strata hydrodynamic environment isweak, and is more suitable for deposition of silt and clay.(2) According to illite, smectite content in clay minerals of surface sediments, the study area is closer to the Yellow River. From the surface and the sediment cores illite-smectite-(chlorite+kaolinite) triangular end-member, clay minerals in sediments areclose to the South Yellow Sea, and is much closer to the Yellow substances, anddeviation from the Yangtze substances.(3) Based on the characteristics of detrital minerals, it is divided into three areas:Laoshan-Jimo offshore mineral district, Haiyang mineral waters area and Rushannearshore mineral district. Every Districts material comes from various sources, and itmainly contains near source and far-source material. Among then, near source whichhas erosion material from coastal and islands, and also carried by rivers into the sea;while far-source material includes far modern Yellow River substance.(4) Utilizing the discriminant function to select the rare earth elements of Ce/La andSm/Nd elements as a comparison, and using the small river nearby (Wulong andRushan rivers) and China’s Yangtze River, the Yellow River as the end of the dollar,along with section line3DF values were calculated. Results show that the material andthe Yellow River sediments in the study area sediments are close to the maximum extent.To eliminate the effects of grain size, the more stable geochemical environment elementratio were compared with the ratio of the rare earth element, such as Ti/Al, Ti/Zr, Gd/Nd, La/Yb, La/Co, etc. Figure shows that, elemental ratios in surface sediments of thestudy area are closer to the Yellow River sediments, while deviating from the YangtzeRiver deposited material. Meanwhile, surrounding river flows into the sea also has someimpact on its provenance.(5) Using SPSS software for R-type factor analysis, principal component extractionand the maximum variance rotation method analysis, the surface sediments of constantelement, trace elements, sediment type and other parameters obtained four main factors,the cumulative variance adds up to89.39%. F1factor significantly associated withsediment type, which reflecting the relationship between the elements and the sedimentgrain size distribution, in order to pro-clastic combination of elements; F2factorrepresents a combination of elements of biological carbonate deposition components; F3factor variance rate of9.62%, a combination of the factors of sand, silt and TiO2; F4factor represents the impact of the sea on the surface sediments. Comprehensive study of clay minerals, detrital minerals, element geochemistry,material sources of muddy area in south of Shandong Peninsula area are mainly from theYellow River, but also be affected by the coastal provenance. |
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