青海柴达木盆地干盐湖盐层的^(10)Be分布和铀系年龄研究  

10Be DISTRIBUTION AND U-SERIES DATING OF SALT BEDS IN DRY SALT LAKES IN THE CHAIDAMU BASIN, QINGHAI, NORTHWEST CHINA

作　　者：梁卓成[1] 顾德隆[2] 

机构地区：[1]中国科学院地球化学研究所 [2]美国南加利福尼亚大学地质系

出　　处：《地球化学》1986年第4期291-297,共7页Geochimica

摘　　要：用高灵敏度加速器质谱计测量柴达木盆地干盐湖一个钻孔岩心(36.4°N,94.5°E)上下两个盐层的盐相和碎屑相的宇宙成因核^(10)Be的分布,结果表明^(10)Be的地化特征是亲碎屑相的。在近几万年以来,^(10)Be的沉降速率是不均匀的,似乎与气候有关,湿润期的沉降速率大于干旱期的沉降速率。用^(230)Th法测定了两个盐层的年代。校正后下部盐层的年龄说明该地区气候由湿润变为干旱期约发生在距今45ka。这和深海岩心2阶段和3阶段交界的^(230)Th年龄(36.3±1.8ka)基本吻合。The distributions of cosmogenic nuclide 10Be in the upper and lower salt anils from a core (36.4°N,94.5°E) in the Chaidamu basin,Qinghai,China have been measured using the accelerator mass spectrometer.The comparison of these 10Be results measured on saline and detritus phases shows that the Geochemical behaviour of 10Be is detritusphile.In this area 10Be deposition rates are different in the past tens of thousands of years,which is suggested to be related to climatic fluctuations during late Pleistocene.It seems that: 10Be deposition rates were higher in wet environments than in dry environments.The 230Th-based age estimates of two salt units have been determined.The corrected age results of the lower unit show a climate shift from wet into dry at about 45 ka ago in this area.This is in agreement with the 230Th age (36.3±18ka) of the deep sea core sample at the boundaiv between Stage 2 and Stage 3

关 键 词：柴达木盆地 干盐湖 ^10Be分布 铀系年龄 同位素 

分 类 号：P597[天文地球—地球化学]