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宇宙成因核素可用于河流阶地测年,然而保存于阶地面上的漂砾暴露年龄是否能代表其形成年代还缺乏深入研究。应用宇宙成因核素~(10)Be对怒江丙中洛河段第三级阶地上的花岗岩漂砾进行测年研究,结果显示继承性组分可以忽略,而风化侵蚀将对其暴露年龄产生较大影响。基于采集自第三级阶地保存较好的基岩中石英脉样品,应用有效暴露年龄、暴露时间与风化速率间的关系图解出花岗岩漂砾的风化速率为0.3cm/ka,并据此得到第三级阶地的形成年代大约为150～203ka。
Cosmogenic nuclides can be used to date the terraces of rivers, however, whether the exposed age of boulders stored on the terrains can not represent the formation age of them is still lack of further study. The dating of the granite boulders on the third terrace of the Bingzhongluo section of the Nujiang River using the cosmic genetic nuclide ~ (10) Be shows that inheritance components can be ignored and the weathering erosion will have a significant impact on the age of exposure . Based on the samples of quartz veins collected from the bedrock of the third terrace, the weathering rate of granite boulder is 0.3cm / ka using the relationship between effective exposure age, exposure time and weathering rate, Three terraces formed about the age of 150 ~ 203ka.