黄土中碳酸盐含量变化及其古气候记录——以兰州红咀寺剖面为例  

CONTENT OF CARBONATE OF LOESS AND SIGNIFICANCE OF PALAEO-CLIMATE:TAKING HONGZUISI SECTION IN LANZHOU AS AN EXAMPLE

作　　者：彭红霞[1] 李长安[1] 杨桂芳[1] 余华贵[1] 黄长生[1] 

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地质科技情报》2003年第1期53-55,共3页Geological Science and Technology Information

基　　金：国家自然科学基金资助项目 (4 9972 0 5 7;40 172 0 61)

摘　　要：以兰州红咀寺剖面为例 ,以 2 cm的间隔采样 ,进行了碳酸盐含量的测定 ,获得数据 892个 ,与其它古气候指标 (磁化率、有机碳总量 )进行对比后揭示了该地区近 3 0× 10 3 a来气候变化的频率及突变事件。3 0× 10 3 a以来主要可以分为 4个阶段 :暖湿期(3 3× 10 3 ～ 40× 10 3 a B.P.)、凉偏干期 (3 0× 10 3 ～ 2 7× 10 3 a B.P.)、寒冷干燥期 (2 7× 10 3 ～ 10× 10 3 a B.P.)、暖湿期 (10× 10 3 ～ 3× 10 3 a B.P.) 。Carbonate is one of the common chemical components in Quaternary sedimentary rocks.The content in loess has the significance of palaeo climate.Taking Hongzuisi loess section in Lanzhou as an example,sampling in 2 cm intervals,and testing the w (CaCO 3) as mass fraction of carbonate in loess,gaining 892 datum,the paper finds that the 17 m high resolution records a detailed history of palaeo climate change since 30×10 3 a in Lanzhou.According to the curve of the w (CaCO 3),the palaeo climate in the area can be divided into 4 main stages:33×10 3-30×10 3 a B.P.,when the w (CaCO 3) is falling,and the climate is cold and dry at the beginning,but the climate is warm and wet at the end of this stage;30×10 3-27×10 3 a B.P.,when the w (CaCO 3) is higher,the biggest value is 19% at about 28×10 3 a B.P.,corresponding to the cold and dry;27×10 3-10×10 3 a B.P.,when the w (CaCO 3) is stable,but there are two big fluctuations in 14×10 3-10×10 3 a B.P.,and the w (CaCO 3) reachs the highest.The climate becomes colder and dryer;Younger Dryas Event 10×10 3-3×10 3 a B.P.,the big warm period in Holocene,when the w (CaCO 3) fluctuates frequently and the climate is warm as a whole in this period.

关 键 词：红咀寺剖面 黄土 碳酸盐 古气候 兰州市 成壤作用 

分 类 号：P532[天文地球—古生物学与地层学] P642.131[天文地球—地质学]