Research Of Structural Geology And Genesis Of Pollen Assemblages And Paleoenvironment Since Holocene In The Wei Nan Region

With the understanding of the loess- paleosol and its significance in the ancient climate, since the international the development of the ancient climate research especially in recent decades. To a great extent, promote the ancient climate research of loess-paleosol in our country, trying to become a quantitative to qualitative description of the ancient climate science exploration. The acquisition of the loess plateau surface pollen samples in total of 196, vegetation quadrat survey in 196, the first large area in the loess plateau area density, surface soil pollen samples collection and synchronous modern vegetation investigation, using the data of the loess plateau region, surface soil pollen and initially established the relationship between surface loess pollen and plant ecological-climate. Wei Nan loess plateau region in China is one of research hotspots in the ancient environment.Combined with 6 meters of Wei Nan section, a total of 150 sampes and analyzing sporopollen samples, quantitative reconstruction of the Wei Nan region of paleoclimate evolution since the holocene. In 14.64 ~ 8.49 ka BP phase, the average temperature of 8.39 ℃, average rainfall of 178.8 mm. In 8.49 ~ 5.036 ka BP phase, the average temperature of 14.63 ℃, the average rainfall of 245.51 mm. In 5.036 ~ 3.58 ka BP phase, the average temperature of 12.56 ℃, average rainfall of 261.06 mm. In 3.58 ~ 3.29 ka BP. phase, the average temperature of 7.90 ℃, average rainfall of 205.87 mm. In the 3..29 ~ stage so far, the average temperature of 8.91 ℃, the average rainfall of 123.76 mm.Quantitative reconstruction of Wei Nan region since the holocene climate change showed that the holocene Wei Nan area change and the change of the holocene epoch of the classic broadly in line, the early holocene overall performance for quick heat precipitation increased obviously, and in the middle of the holocene, is the best climate period, the highest temperature rainiest. Since the late holocene, the climate has the change trend of temperature reduce and rainfall decrease again.Reconstruction loess plateau climate change history is to know the world,the bridge of global climate change, understand the ancient climate change characteristics, not only can understand different cycle characteristics and mechanism of climate change, but alsoprovide data for future climate, to explore quantitative restore Wei Nan loess plateau region of climate change on ecological environment evolution and development of the region and even have a great significance of the whole country.