蒋家沟现代泥石流表层堆积物热释光信号的沿沟变化  

The TL Signal Variation on Modern Surface of Debris Flow Deposits Along the Jiangjia Ravine(Yunnan,China)

作　　者：宋波[1] 魏明建[1] 赵秋月[1] 周锐[1] 张彬[1] 

机构地区：[1]首都师范大学释光断代实验室,北京100048

出　　处：《核电子学与探测技术》2013年第3期379-383,共5页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金资助项目(40871017);北京市自然科学基金项目(8102013);北京市自然科学基金重点项目B类(KZ201210028034)

摘　　要：连续两年对沿蒋家沟主沟(门前沟和多照沟交汇处至蒋家沟与小江交汇处)新发生的泥石流表层堆积物等距取样,测定热释光信号,计算出本底年龄值。研究表明:2010年泥石流表层堆积物的等效剂量和本底年龄沿沟向下游总体增大,2011年总体减小。2011年呈规律性波动,2010年相对于2011年规律不明显。2010年泥石流表层堆积物的辐照响应有较大差异,2011年则基本相同。随着支沟泥石流堆积物汇入主沟,本底年龄值先增大后减小,支沟泥石流堆积物的加入重置了主沟的退火起点。为确保泥石流释光测年机制的可对比性,应该选用对辐照响应较一致的样品,以不同的支沟退火过程为基础研究主沟的退火机制。本工作为进一步揭示泥石流的释光退火机制,开展古泥石流的释光测年提供技术支撑。Modern surface debris flow deposits were equi -distantly sampled along the main ditch in Jiangjia valley located at the interchange from Menqian gully and Duozhao gully to Jiangiia valley and Xiaojiang River for two successive years, the TL signals were measured and the background values were calculated. The research demonstrated that the trend of equivalent dose and background ages in the surface of debris flow deposits along the main ditch increased in 2010, whereas decreased in 2011. 2011 showed the regular fluctuations but no obvious rule in 2010 compared to 2011. The irradiation dose responses on the surface of debris flow deposits in 2010 had bigger difference, and those in 2011 were basically the same compared with each other. With the import of debris flow deposits from tributary into the main ditch, the residual age increased at first and then reduced, the support of tributary reset the annealed point of the main ditch. To ensure the correlation of debris flow dating studies , samples in the study should be chosen from good consistency, and studies of the annealing mechanism of main ditch should be based on the annealing process of the tributary. The present work can provide technical support in revealing the annealing mechanism of debris flow deposits and carrying out the ancient debris flow deposits dating.

关 键 词：等效剂量 热释光 泥石流 堆积物 

分 类 号：TL824[核科学技术—核技术及应用]