Grain-size Of Sand Materials Of Tamarix Cones And Environmental Change In The Southern Region Of Taklimakan Desert

Taklimakan Desert is located in the center area of Tarim Basin in Xinjiang. Its north isTianshan, the south is Kunlun Mountain, the west is Pamirs plateau, and it reaches east to LopNur Region gradually. The climate belongs to the extreme drought warm temperature zonecontinental with little rainfall, high evaporation, a big temperature difference between day andnight. Because of its special climate environmental conditions, there has developed a kind ofunique biological geomorphic type in arid region that is Tamarix Cone. Some of them haveclear structure of “annual stratum” that has the function of dating and storing environmentalinformation as tree rings. So we can recover and rebuild the climate environmentalinformation in decent hundreds of years based on the sedimentary veins of Tamarix Cone.The researched area of this paper is Minfeng County and Cele County which are locatedin the southern region of Taklimakan Desert. The sampling points we chose are Endere site,south of Endere pasture and northwest of Damagou, where distribute three typical TamarixCones. We utilize the geomorphology method, on the basis of inspecting and observing on thespots, combining with the characteristic of grain-size, to reveal the climate and environmentalchanges of this region and to analyze the influenced factors. The main conclusions are asfollows:(1) Tamarix Cones in this region have developed under the common sand source andwind condition, and have a similar sanddune form evolution.(2) Different Tamarix Cones in the southern region of Taklimakan Desert mainly consistof the fine sand. Also, the parameter of grain-size characteristics, and very little gravel sandcontent, grain-size distributed curve as well as accumulated probability curve have strongrelevance.(3) The sand materials in the southern region of Taklimakan Desert mainly come fromthe hinterland of the desert, the grain-size of sand is relatively finer.(4) The changes of the grain-size of sand materials show that in recent a hundred of yearsthe regional climate has changed from the drought to the moist.(5) The parameter of grain-size characteristics of the sedimentary vein of Tamarix Cone is affected by biological environment. According to the thickness of sedimentary vein ofTamarix Cone, the sandy environment could be divided into four changed stages: from1972to2011, the sandstorm activity is weak; from1950to1969, the strength of sandstorm isgeneral; from1930to1949, the sandstorm activity had strengthened obviously; from1884to1929, the strength of sandstorm had decreased obviously.