罗布泊“大耳朵”地区L07-10剖面沉积特征及其环境指示意义

对罗布泊“大耳朵”地区L07-10剖面进行沉积学观察,结合盐分、沉积物14C测年等分析,结果表明,L07-10剖面自上而下主要有3个层次：盐壳层、泥盐混合层、淤泥层。整个剖面不同年份,不同层次盐分变化存在一定规律性,结合剖面沉积学特征,其对罗布泊的演化具有可能的指示意义。反映了罗布泊在发展演化过程中,主要经历了淡水湖-盐湖-干盐湖的发展阶段,指示区域气候持续干旱化的特点,但在气候总体干旱的背景下,出现多次气候干湿波动变化。罗布泊的演化主要经历了淡水湖-盐湖-干盐湖三个发展阶段。

The Sedimentary Characteristics of L07-10 Profile and Its Environmental Indicator in Lop Nor "Great Ear"Area

The study was conducted to survey sediments characteristics, pollen assemblage characteristics, geochemistry characteristics and to analyze ^14C chronology in L07-10 sediments profile. The results indicated that there are three main strata sequences from top to bottom of the L07-10 profile, salt crust,admixture of mud and salt, silt. There was a regularity in the salt change of profile and different strata sequences. It was found that the evolution of Lop Nor was of indicative meaning,on the basis of the profile sedimentary characteristics. The evolution process of Lop Nor mainly went through the development period of freshwater lake-saltlake dry salt lake. The progressive drought existed in the indicative area. However, under drought climate,there were changes of drought climate and moistrue climate.