论文部分内容阅读
萨拉乌苏河流域米浪沟湾剖面萨拉乌苏组含7层古流动沙丘砂、4层古固定—半固定沙丘砂。对这些沙丘砂的沉积构造观察以及粒度、扫描电镜和常量化学元素分析结果表明:(1)这些沙丘砂具有与现代沙丘砂相似的风成沉积构造特征;(2)粒度及其参数——Mz、!、Sk和Kg,以及主要化学组分SiO2、Al2O3和TOFE也与现代沙丘砂相近;(3)Mz-“、SiO2-Al2O3+TOFE散点图和概率累积曲线显示这些沙丘砂与萨拉乌苏组中的河湖相、古土壤差别明显,而与现代沙丘砂一致;(4)石英砂颗粒具有良好的磨圆以及碟形坑、新月形坑、麻坑、上翻解理薄片、硅质沉淀和硅质裂纹等表面结构特征,反映其曾受持久的风力搬运作用。沉积构造、粒度、石英砂颗粒表面结构和化学元素等多个方面具备了与现代沙丘砂类似的风成特征,证明这些沙丘砂的成因是风成的。
The Sara Wusu Formation in the Miurangangwan section of the Sara Wusu River Basin contains 7 layers of ancient mobile dune sand and 4 layers of ancient fixed-semi-fixed sand dunes. The sedimentary structure of these sand dunes and the results of particle size, scanning electron microscopy and constant chemical element analysis show that: (1) These sand dunes have similar characteristics to the modern sand dunes; (2) The grain size and its parameters - Mz , Sk, and Kg, and the main chemical components of SiO2, Al2O3 and TOFE are also similar to modern sand dunes; (3) Mz - ”, SiO2-Al2O3 + TOFE scatter plot and probability cumulative curves show that these sand dunes and sands The lacustrine and lacustrine facies in Lausu Formation are obviously different from those in ancient soils, but they are consistent with modern sand dunes. (4) Quartz sand particles have good roundness, as well as craters, crescent-shaped pits, The surface features such as thin slices, siliceous sediments and siliceous cracks indicate that they have been subjected to long-lasting wind handling, and the sedimentary structures, grain sizes, surface structures of quartz sand grains and chemical elements have similar wind characteristics to modern sand dunes As a result, it is proved that the origin of these sand dunes is of great success.