Analysis Of The Quaternary Sedimentary Environment In Kunming Basin

Combining with the forefather data, the quaternary lithostratigraphy of study area in KunMing Basin is classified to 4 formation: DianCHi, ZhongYing, GuanDu and HaiGeng.Refer to the research findings of CHengDu Research Institute of Geosciences and Minerals(1990) and Nanjing Research Institute of Geography and Lake of Chinese Academy of Sciences(1989), according to the Guidebook of China Stratum(2000), the chronostratigraphy of Kunming Basin is divided into 4 age: the bottom of the Quaternary corresponding to M/G Boundary, age is 2.6Ma;the Bottom of the Mid-Pleistocene corresponding to B/M Boundary, age is 0.78Ma;the Bottom of the Upper-Pleistocene corresponding to the Blake event, age is 0.128Ma;the Bottom of the Holocene corresponding to the Gothenburg event,age is 0.012Ma.According to the forefather borehole data, the Quaternary sedimentary environment of KunMing Basin is analysed. Especially for the representative borehole KZ2-3 of WangJiadui field, we have made detailed grading analysis about it.In the south of the Basin ,the quaternary sediment is major in lacustrine facies, and the north is major in alluvial-diluvial. Since early-Pleistocence, evolution of the Basin has gone through follow process: fault to Subsicence to Abortion to Dieout.By the analysis of the sporopollen data about the representative borehole, we put out the climatic evolution process of the Basin, especially for the later-Pleistocence. The coldest time of the Basin in quaternary is early-Pleistocence, and the warmest time is later-Pleistocence. From late mid-Pleistocence to Holecence, KunMing Basin has gone through follow process: cool and dry to warm and subhumid to warm and dry to moderate and dry to cool and wet to warm and subhumid to warm and dry.