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讨论了~936)Cl的成因、~(36)Cl断代法的原理及测试方法。自1987年以来,应用该方法测得柴达木盆地尕斯库勒湖和大浪滩湖石盐的沉积年龄,并与~(14)C,~(230)Th和古地磁测年法所测得的年龄数据进行对比,结果均在误差(1δ)范围内相吻合,表明石盐的~(36)Cl断代法是可行的,获得的年龄数据是可靠的。 相似文献
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The Qaidam Basin is. a tectonically controlled depression at 2700 m altitude on the northern margin of the Tibet Plateau. A succession of Neogene clastic sediments indicates lake depocentre migration from NW to SE. Towards late Pliocene, evaporative conditions developed with formation of gypsum, halite, celestite, mirabilite and bloedite. Continued deformation through Pleistocene developed a series of NW- SE trending domes and troughs. This setting continued to exert a controlling influence on basin and brine evolution and the progressive development of sulfate to chloride brines as, dry conditions intensified in late Pleistocene, at the end of which, extensive flat floors were formed in Dalangtan, Qarhan and other playas.The, model, which was set up based on the synthetic analyses, divides the fluctuating palaeoclimate since 750ka,B. P. into 11 warm and humid stages and 10 dry and cold stages. The water of the lakes evaporated during the dry-cold periods and were freshened during the warm-humid periods 相似文献
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青海察尔汗盐湖达布逊区段和别勒滩区段的成盐年代 总被引:5,自引:0,他引:5
88-01孔和89-04孔是1989年后笔者用14C和230Th两种方法较为系统的测定了年龄的钻孔剖面。本文以此两孔为主,结合已有年龄数据的钻孔,重点讨论了达布逊区段的成盐年代,并根据88-01孔校正后的年龄,将达布逊区段四个大盐层的底板年龄大致划分为:S1约50000a.B.P.左右;S2约为36000a.B.P.左右;S3约30000a.B.P.左右;S4约18000a.B.P.左右。根据别勒滩区段CK2022,CK6和CK1308三个钻孔剖面,讨论了此区约25000a.B.P.成盐年代。 相似文献
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1993年采用α谱仪和大面积屏栅电离定对柴达木盆地盐湖水、地下水、河水以及地表和两个钻孔沉积物中的U,Pu和Am进行了测定。结果表明,各类水样中239Pu(含240Pu,下同)的平均含量高出表层海水约1000倍,其239Pu/238U的活度比在0.001-0.530之间;两钻孔沉积物中239Pu的平均值分别为49±0.8mBq/g和2.4±0.5mBq/g,239Pu/238U的活度比为0.141和0.088,由此探讨了U,Pu和Am的分布特征、239Pu/238U比值的变化规律以及沉积物和水中Pu的来源。 相似文献
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七十三万年来柴达木盆地察尔汗盐湖古气候波动的形式 总被引:21,自引:2,他引:21
本文采用14C、230Th和古地磁法,测定了察尔汗盐湖CK-6孔岩芯的年龄,并根据对该孔有机碳含量变化的研究,讨论了0.73Ma以来古气候波动的形式。初步结果表明,CK-6孔可与洛川黄土及深海沉积钻孔的气候曲线进行对比,认为全球性气候事件在青藏高原内部同样有明显的反映。 相似文献
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Heavy water eoutcnts were determined for brines from Some salt lakes, and for water samples from rivers, springs and oil field by temperature-float method. Because the salt lakes studied are situated in cold, arid region of high altitude, the heavy water content in concentrated brines is much higher than that in rivers and springs due to vigorons evaporation, with a maximum value of 5.9 γ higher than that in running water of Peking. Discussion is also given to the dependence of heavy water variation upon season, depth of lake water, density, the degree of brine metamorphism,and crystallization of minerals containing crystalline water. 相似文献