中国新疆博斯腾湖全新世沉积环境年代学特征  

The Chronological Characteristics of Bosten Lake Holocene Sediment Environment in Xinjiang, China

作　　者：张成君[1] 曹洁[1] 类延斌[1] 尚华明[1] 

机构地区：[1]兰州大学资源环境学院,兰州730000

出　　处：《沉积学报》2004年第3期494-499,共6页Acta Sedimentologica Sinica

基　　金：国家重点基础研究规划项目"中国西部干旱区生态环境演变与调控研究"(批准号 :G1 9990 4 350 1 );国家自然科学基金项目 (批准号 :40 0 4 1 0 0 4 )资助

摘　　要：通过对博斯腾湖沉积物湖芯样品进行13 7Cs,14 C -AMS测年分析 ,湖芯剖面上有明显的 1986年的切尔诺贝利核事故蓄积峰 ,以及 1975年和 196 3年次蓄积峰 ,这些13 7Cs蓄积峰对博斯腾湖现代沉积有明显的时标意义。通过质量深度与年代分析 ,博斯腾湖的沉积速率相对稳定 ,平均沉积速率为 0 .13± 0 .0 1g/cm2 .a。与14 C年代获得的中全新世以来的平均沉积速率 0 .13± 0 .0 3cm/a和 0 .12± 0 .0 5cm/a相似 ,表明博斯腾湖中全新世以来的沉积环境较稳定 ,并且也说明14 C -AMS测年分析所得的结果较为可靠 ,可以利用博斯腾湖沉积物样品测定的14 C年代进行线性回归作年代校正 ,由于湖泊沉积物中老碳效应的影响 ,博斯腾湖沉积物有机质14 C测年偏老约 6 5 0a左右。Cs and 14 C AMS were analyzed for the Bosten Lake sediment cores in Xinjiang, arid China. In the BST-4 core 137 Cs section, there are obvious 1986 Chemobyl nucleus accident peak and 1975, 1963 peaks, which are important age characteristics for the Bosten lake sediment. The sedimentation rate, which was average 0.13±0.01 g/cm 2 .a, was stable in the Bosten Lake by analysing the mass depth and ages. It is very similar to that from the 14 C age, 0.13±0.03cm/a for BSTC-1 core and 0.12±0.05cm/a for xb46 core, in Bosten Lake after middle Holocene and show that the depositional environment was stable and the 14 C ages were accurate. From the 14 C age of the samples in Bosten Lake, it can be calibrated the old carbon effect produced by the hard water in the lakes and old carbon effect can lead to the old age for the 14 C age in analysing the lake organic matters in sediments. We obtained the result of about 650a old effect in Bosten lake from the 14 C age and the sedimentation rate by the 137 Cs data.

关 键 词：全新世 沉积环境 地质年代学 中国 沉积速率 

分 类 号：P534.632[天文地球—第四纪地质学] P597.3[天文地球—古生物学与地层学]