- 责任者：Shao Tianjie (College of Tourism and Environment Science ; Shaanxi Normal University ; Xi’an 710062 ; China) ; Zhao Jingbo
- 刊名：Journal of Mountain Research
- 出版年：2013
- 卷期：31(4)
- 关键词：沙丘 ; dunes ; 内蒙古 ; Inner Mongolia
- 页码：p.434-441
- 图表：illus., 1 table, 25 refs.
- 分类号：1400
- issnNo：ISSN1008-2786
- isbnNo：CN51-1516/P
In order to find out the formation and developmental mechanism of megadune, an emblematic megadune in the densely distributed central area in the southeastern Badain Jaran Desert was chosen as the study object. Using a combination of the material composition and physiognomy zonations of a single megadune to research the forma- tions of megadune systematically and quantifieationally. Method of particle size analysis was used to obtain the data of physiognomy zonations at the windward slope, sediment size composition at the different parts of megadune. Ac- cording to these data, further discuss the relationship between sediment size composition and landform zoning char- acteristics of megadune windward slope and wind dynamic conditions at different parts of megadune. Some results were drawn as follows：l, the particle size of megadune was comprised by coarse silt, very fine sand, fine sand, medium sand and coarse sand. The content of the fine sand was the highest, followed by the medium sand and coarse sand, the very fine sand and coarse silt were less. 2. The particle size of sediment on surface layer of wind- ward slope was thicker than that on sublayer of windward slope and surface layer of leeward slope, and its average kinetic energy of transportation medium also was maximal. 3. The sediment particle size became smaller from the bottom to the top of the slope, which was caused by the differences of forming prpcess and dynamic effect. 4. Ac- cording to the observational data of secondary physiognomy, the windward slope of megadune was divided into low- lying sandy depression zones, sparse simple barchans or barchanoid chains zoning, dense barchans and barchanoid chains zoning and steep main peak zoning from the bottom up. 5. That aeolian sand material was not carried to the middle and upper part of megadune one time, but carried to the upper part of megadune by numerousness wind- force transport. Firstly, medium sand and fine sand in the lower of megadune was carried to the middle part, and shaped barchan and barchanoid chains. After repeatedly transport, finally the peak of megadune was shaped.