Sediments' Elementary Analysis Above Active Sand Dunes In Minqin Oasis And Its Adjacent Deserts

Minqin Oasis is located between Badain Jaran Desert and Tengger Desert, and it is the natural barrier to keep back the two deserts'Confluence. There were a great number of lakes, abundant water resourse and thick grass in Minqin Oasisi being fed by the Shiyang River, which made this area always be the Chinese ethnic minorities'natural pasture and play an important role on the development of the Chinese nation in history. However, with climate change and the increasing ability with which human being can change the nature dramastically, the water resourse of Shiyang River was decreasing and the ecological environment of Minqin was degenerating by the factors of dry, rainless, war and over exploitation.Under the circumstance of developing the west regions and paying attention to environment protection, governments have begun to draw the blueprint of ecological restoration. The expectation of premier Wen Jiabao "never allow Minqin Oasis become the second Lop Nor Lake" have been encouraging people constantly plunge into the activity of sand protection and sand control.Sediments above active sand dunes in Minqin Oasis and its adjacent deserts were studied. XRF was applied to test sediments'element. Surface sediments elementary transference was discussed based on correlation coefficient. Located sand sourse by the method of elements normalization and used enrichment factor, Si/Al and Si/(AL+Fe), chemical weathering index, discriminant function to confirm the conclusion. Finally, Minqin Oasis was divided into four regions based on the conclusion of sand analysis, respectively, upstream region, midstream region, lowerstream region and terminal lake region in Shiyang River drainage of Minqin. There were some conclusions according to the results. The sediments of upstream region stemed from Tengger Desert, its south.so its sand substance was transmitted from its neighbor. The sediments of midstream region stemed both from Minqin Oasis and Tengger Desert which located its south. The sediments of lower region were complicated, but Badain Jaran Desert-Minqin Oasis Sand line zone was the most possible sourse region. The sediments of Terminal Lake stemed from Badain Jaran Desert, which transmitted with west wind far away from Minqin Oasis.