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• CN 62-1072/P
• ISSN 1000-0240
• 创刊于1979年
• 主管单位：中国科学院
• 主办单位：中国科学院寒区旱区
•                  环境与工程研究所
•                  中国地理学会

• 研究论文 •

### 天山博格达峰地区冰碛物细碎屑的岩矿特征

1. 中国科学院兰州冰川冻土研究所
• 出版日期:1984-11-25 发布日期:2012-04-26

### Mineriat Characteristics of the Fine-Grained Moraine in Bogda Region, Tian Shan

Tang Yongyi

1. Lanzhou Institute of Glaciology and Cryopedology, Academia Sinica
• Online:1984-11-25 Published:2012-04-26

Abstract: Based on the polarization microscopic analysis of moraine in grain size 0.25-0.01 mm in Bogda Region, the characteristics of its fine-grained fragment component may be summed up as follows:1. General characteristics (1) Complexity of moraine component. It consists of more than 40 kinds of light minerals, heavy minerals and rock debris, one of the characteristics of glacial deposits in moraines of Himalaya and Tian Shan mountains.(2) Low maturity of moraine minerals. Shown in the high rate of heavy components and unstable heavy minerals, low index of maturity in minerals (<2), weak weathering, poor sorting, low index of roundness (2-3), etc.,another characteristic of glacial deposits.(3) Wavy valley shape of roundness index curve particular to glacial moraine deposits.2. Regularity of regional distribution of fine-grained components.The content of acanthconite on the top of Mt. Bogda is higher than that on the northern and southern slopes. The content of pyroxene and amphibole on the northern and southern slopes is higher than that on the top of Mt. Bogda. The type of mineral groups is simple on the top of Mt. Bogda and on the southern slope, but complex on the northern slope, reflecting mineral distribution as mentioned above shows the closer relationship of the glacial sedimentation to bedrocks in Bogda region than that in other localities.3. Mineral characteristics of moraine in different glacial perieds.(1) In the moraine from ancient to actual, the contents of heavy component and unstable heary mineral change from low to high, and the contents of stable heavy mineral and ZTR value vary from high to low. It .shows that mineral maturity of ancient moraine is higher than the modern moraine. This characteristic may be taken as the basis of glaciation division.(2) The mineral composition of moraine changes from complex type to simple as the moraine turns from ancient to modern. This regularity correspounds to different glaciations and their dimensions, clear evidences of development and decline of glaciers.