长江上游水系变迁的河流阶地证据

发布时间：2018-06-12 02:45

本文选题：长江上游 + 重矿物　；参考：《第四纪研究》2006年03期

【摘要】：以金沙江石鼓-巧家河段与川江宜宾-重庆丰都河段的阶地堆积物物质成分变化为着眼点研究了长江上游水系变迁。分河段对阶地堆积物重矿物成分进行时空对比后发现,金沙江下段沿岸各地的高位阶地重矿物成分差异较大,说明当时该地区尚未有贯通的金沙江,而可能是独立的小水系。白汉场、剑川、漾濞、元江等地古河谷堆积物样品重矿物成分的相似说明古金沙江可能是在石鼓、鸿文附近向南经过白汉场-剑川-漾濞盆地入红河的。川江各处高位阶地重矿物成分的差异说明当时该地区也存在分散的水系。金沙江下段以及川江贯通之后汇水东流,现代长江上游水系格局形成,并发育了重矿物成分相近的低阶地。
[Abstract]:Based on the material composition changes of terrace deposits in Shigu Qiaojia reach of Jinsha River and Yibin-Fengdu reach of Sichuan River, the changes of water system in the upper reaches of the Yangtze River are studied. By comparing the heavy mineral composition of terrace deposits in different river segments, it is found that there are great differences in heavy mineral compositions of high terraces along the lower reaches of Jinsha River, indicating that the Jinsha River was not connected in this area at that time, but may be an independent small water system. The similarity of heavy mineral composition in the samples from Baihanchang, Jianchuan, Yangbi and Yuanjiang shows that the ancient Jinsha River may have entered the Red River through the Baihanchang-Jianchuan-Yangbi basin in a southward direction near Hongwen. The difference of heavy mineral composition of high terrace in various parts of Chuanjiang River indicates that there were scattered water systems in this area at that time. In the lower part of Jinsha River and after the crossing of Chuanjiang River, the water system pattern of the upper reaches of the Yangtze River is formed, and a low terrace with similar heavy mineral composition is developed.
【作者单位】：南京大学城市与资源学系南京大学城市与资源学系南京大学城市与资源学系
【基金】：高等学校博士学科点专项科研基金项目(批准号:20020284004) 国家自然科学基金项目(批准号:40272126)联合资助
【分类号】：K928.42

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