Grain Size Distribution And Its Environmental Significance Of Qinhuangdao Since The Late Pleistocene

Qinhuangdao Quaternary general lack of lower Pleistocene , The middle Pleistocene mainly in Shanhaiguan area,and the upper Pleistocene were generally developed. Holocene in the Beidaihe district and the Haigang district were widely distributed and in the Shanhaiguan area were only distributed on river sides. In this paper, based on the main application of this method of particle size analysis, combined with lithology, grain size of the controlled drilling of its characteristics in detail for analysis and comparison with other drilling of Qinhuangdao discussed since the late Pleistocene Characteristics of sedimentary environment.Qinhuangdao controlled drilling of its average particle size of sediment between 1.36 ~ 7.31φand plural mainly between 0.38-8.5φ. particle size changes largely with poor sorting tapering from bottom to top. The skewness is nearly symmetrical, positively skewed and very positively skewed mainly kurtosis-based medium and flat.By the characteristics of probability curve and frequency curve, the water condition of the upper Pleistocene of controlled drilling was weakening from bottom to top and the Holocene was varying in early turbulent changing to stabilizing lately.By combining the various parameters of particle size characteristics with the various cumulative curve ,the C-M plot and pollen characteristics, the upper Pleistocene sedimentary environment was alluvial, alluvial facies, the Holocene mainly dominated by marine sediments.By comparing with the Controlled drilling of Haigang district, and combined with previous research results, the upper Pleistocene fluvial sedimentary environment of Qinhuangdao from north to south was the ice water - Alluvial Phase - Alluvial Phase and the Holocene was river- lagoon- tidal phase.