Quaternary Sedimentary Environment Analysis In Handan

This paper began from the holes study, divided rock stratum and age stratum in HanDan city according to lithology change features and former stratum studies, analyzed sediments features and sediments change trend of representative bores by granularity method, analyzed sediment conditions change since the Quaternary period through sporopollen analysis and well log features analysis, and analyzed depositional environment evolution change since Quaternary period on the basis of transverse contrast and region depositional environment features. Such main conclusions can be drawn from the study:1.Strum of the Quaternary period in HanDan city can be divided into Gu'an formation (Qp¹G) of the lower Pleistocene Series, Yangliuqing formation (Qp²Y) of the middle Pleistocene Serie Ouzhuang formation of the upper Pleistocene Series, and Holocene series (Qh), on the basis of bores lithology feature analysis and historical studies. Stratum of the Quaternary period in Handan city can be divided according to abundant ¹⁴C, optical luminescence, thermoluminescence dating data and sporopollen analysis: bottom of the Quaternary period is 2.48Ma, borderline of middle and early Pleistocene is 0.73Ma, borderline of late and middle early Pleistocene is 0.128Ma,and borderline of Holocene and late Pleistocene is 0.012Ma.2. Average grain size, quartile deviations, skewness and kurtosis were calculated and parameter curve feature plots were made.. C-M plot and structure parameter scatter plot showed that transport condition was gravity deposition (i.e. grading suspend) and uniform suspend. Each granularity parameter and curve features of representative bores showed strong hydrodynamics in the lower part and weakening hydrodynamics and poor sorting upwards.Accordant result from size parameter curves showed that energy varies on different deposition stages. From these curves, we can see distinct leap boundary, different amplitude of fluctuation and different frequency. Consequently, theyrevealing a rising trend from down to up about base level of erosion in this hole. Characteristic curves and parameter curves depict a sort of reasonable classification based on the approach of lithostratigraphic and chronostratigraphic.3. A conclude about depositional environment evolving character can be derived from analysis of Lithology feature, Sporopollen., Well log features and grain size. The result showed that representative bores were located at river ways of fan delta and lake basin expanding-river deposition- alluviation and flood deposition -river deposition - lake basin shrinking-lake progression- river process strengthening in middle Pleistocene, lake progression-alluviation and flood deposition-lake basin shrinking- alluviation and flood deposition in late Pleistocene, and lake basin shrinking- alluviation and flood deposition in the Holocene.There was river way sediment of fan delta in HanDan region according to regional deposition backgrounds and 10 field lithology contrasts.