西汉-元初什刹海沉积物植物硅酸体与环境研究——以小石碑胡同工地西壁南剖面为例

Phytolith and its paleoenviromental significance in Shichahai area from the Western Han Dynasty to the Yuan Dynasty——A case of the southern section at the western side of buiding site in Xiaoshibei Hutong

通过对什刹海北岸植硅体进行分类,并运用植硅体示暖指数分析、对应分析的方法,恢复了北京什刹海地区从西汉-元初的古气候与古环境变化,西汉至元初什刹海气候可以分为两个阶段。I期:西汉晚期-唐早期(1980a.B.P-1295a.B.P)总体为冷期,其中西汉晚期-东汉早中期(1980a.B.P-1820a.B.P)、东晋早期-唐早期(1680a.B.P-1295a.B.P)为凉温气候,东汉晚期-东晋早期1820a.B.P-1680a.B.P为剖面最寒冷时期。II期:唐早期-元初(1295a.B.P-580a.B.P)为暖期,气温整体较温暖,内部有小的波动。剖面中芦苇扇型植硅体、硅藻和海绵骨针的出现印证了什刹海低湿地的微环境。另外,什刹海剖面发现的水稻扇型植硅体,为单一依靠历史文献研究历史地理问题提供了新的实证。

According to the classification of the phytolith in north bank of Shichahai, by using the methods of analysis of the Phytolith warm index, the corresponding analysis, and the comparative analysis of the Palynomorph, the changes of the paleoclimate and paleoenvironment in Shichahai area since Western - Han Dynasty to Yuan Dynasty were resumed. During this period, the climate in Shichahai area could be divided into cold period and warm period. The former one（ 1980a. B. P -1295a. B. P） included three periods ：the period from late Western -Han Dynasty to early or middle Estern - Han Dynasty （ 1980a. B. P - 1820a. B. P） and the period from early Eastern -Jin to early Tang Dynasty （ 1680a. B. P - 1295a. B. P） belonged to cool -warm periods, and the period from late Han Dynasty to early Eastern -Jin Dynasty（ 1820a. B. P -1680a. B. P） was the coldest period; while the latter period was the period from the early Tang Dynasty to the early Yuan Dynasty （1295a. B. P - 580a. B. P） , which belonged to warm period. The appearance of fan -shaped phragmites phytolith and diatom, as well as sponge spicule, confirmed the microenvironment of the swampy ground in Shichahai. Otherwise, the fan -shaped Oryza phytolith discovered in the section of Shiehahai was only attested in several samples, but it was demonstrated that the phytolith could be available for the research on the historical rice - planting in Beijing area. However, the history of rice - planting in Shiehahai area requires other sedimentary sections for further confirmation.