Mineral Chemical Characteristics Of The Yangtze River、Yellow River Sediments And Provenance Implications In The Mud Area Of East China Sea

More than one different thickness、patchy muddy sedimentary bodies distributedin the continental shelf of eastern china sea, which are rich in marine、terrestrialenvironmental information, to become a good geological record of high-resolutionmarine environment evolution、Global Change and regional response. Massive inputof terrigenous material by continental runoff (mainly the Yangtze River, Yellow River,etc.) deposited on the formation of muddy bodies make an incomparable importance.It records abundant information of causes, provenance, climate and environmentalaspects, providing a qualitative and quantitative basis for knowing and understandingthe modern geological processes, the area of climate change and the evolution of themarine environment. Currently, the research tracing the provenance based on detritalminerals multi-focused mineral types and combinations, the use of mineral chemistrystudies less and not comprehensive in modern sedimentary ocean. Therefore, based onthe chemical characteristics of detrital mineral hornblende, and establish a newreliable indicator to identify the source of Yangtze River and Yellow River, Furthercarry out provenance research in the mud area of east china sea, it has importantscientific significance in understanding the diffusion and transportation of the tworivers, acquiring the evolution of the eastern shelf argillaceous sedimentary area andfurther comprehending the role of the "source-sink" issues.This paper studies four groups from the Yangtze River, Yellow River estuarywaters and muddy sedimentary samples of five surface-like area、a cylindrical sample.They are analyzed by grain size tests, X-ray diffraction, detrital mineral identification and EPMA。The following conclusions:Amphibole types is various, the majority are Magnesiohornblende, followed byTschermakite, low Ferrohornblende、Ferrotschermakite, compared to the Yellow Riversource, high Magnesiohornblende and actinolite in the Yangtze River, Tschermakite、Ferrotschermakite is Relatively less; on the causes, the majority of both are seniordeterioration, intrusive and metamorphic or metasomatic acidic, relatively highproportion of retrograde or metasomatic amphibole in Yangtze sediments, Yangtzesediments dominated by amphibole in high-grade metamorphic rocks andmetamorphic or metasomatic amphibole, the latter has higher metamorphic grade thanthe former, the distribution of Yangtze amphibole is more dispersed than Yellow,indicating that genetic type and its Corresponding crystalline environment is morecomplex than the Yellow River; Mg/Fe2+is significantly different, the Mg/Fe2+for theYellow River is less than2,Yangtze River is more than2.3. The above is based onrandom test samples and adequate data，which can be used as an effective mineralchemical fingerprint of the Yangtze River, Yellow River. The acquisition ofdifferences above is built on the basis of statistical laws, which can be as effectivemineral chemical fingerprint in Yangtze and Yellow provenance identification.The mineral chemical fingerprint applied well to identify the provenance ofsurface sediments in the mud areas. The results show that, the effects of the YellowRiver in the eastern mud areas are all reflected, where provenance of Bohai Sea andNorth Yellow Sea is mainly Yellow River substance; South Yellow Sea mud is themulti-sourced deposition of the Yangtze River, Yellow River and the Yellow Seastrait substances, but influenced by the Yellow River mainly; the mud area north ofthe Yangtze River estuary is mainly affected by the Yangtze River substances, whilesubstances from the west bank and off the coast added to them also have a significantimpact; the mud area southwest of Cheju Island is influenced by not only the YangtzeRiver, Yellow River, but adding exogenous substances have a significant impact,Initially presumed that rock weathering products from Tananao group doublemetamorphic belt on Taiwan island are flowed into the eastern coast of Taiwan byeastern rivers, after brought to the muddy area by the Kuroshio. The indicators also used to trace the provenance of the core-B03.aftercomprehensively analyzed its particle, clay minerals, detrital minerals and mineralchemical characteristics of typical layers, the results showed that the source supplyand sedimentary environment is stable, the major source of core are the modernYellow River substances transporting and the erosion of Shandong Peninsula shelf、the seabed bedrock. The core is divided into two layers by the depth of85cm based onsedimentary characteristics, the lower deposited layer more affinities the ShandongPeninsula and adjacent seabed rock, suggesting that there may be some changes in thesediment source, combined with210pb dating data analysts believe that the upper andlower boundary may represent the regional response of Yellow River diversion eventsin1855in the eastern shelf of the Shandong Peninsula.