论文部分内容阅读
萨拉乌苏河流域米浪沟湾剖面150kaB.P.以来存在27个由风成砂与河湖相和古土壤构成的沉积旋回。通常后两者的Al2O3、TFe、Mn、TiO2、K2O、MgO、CaO和Na2O含量明显高于前者,而SiO2则相反,构成了与沉积旋回相应的150kaB.P.以来27个元素变化旋回。结合各元素的化学迁移特性、研究区所在的鄂尔多斯高原东南部洼地地貌特征以及季风沙区位置,论证了风成砂中SiO2含量增高,Al2O3、TFe、Mn、TiO2、K2O、MgO、CaO和Na2O相对降低,与干寒多风气候及其影响下石英的大量迁入有关,而河湖相和古土壤中SiO2相对迁移、Al2O3等呈聚集的势态,与暖湿气候作用下稳定性元素Al2O3、TFe、Mn、TiO2和非稳定性元素K2O、MgO、CaO、Na2O都能够从四周地表汇集于本区这种特殊的比较封闭的低地有关。研究表明,萨拉乌苏河流域150kaB.P.以来27个元素变化旋回与该时期北半球冰期-间冰期气候波动诱发的亚洲冬夏季风在毛乌素沙漠的多次更迭具有成因上的联系。
There are 27 sedimentary cycles consisting of aeolian sand, lacustrine and lacustrine facies and palaeosol since 150 kaB.P. In general, the contents of Al2O3, TFe, Mn, TiO2, K2O, MgO, CaO and Na2O in the latter two phases are obviously higher than those in the latter, while the opposite of SiO2 make the 27 elements change cyclically since 150kaB.P. corresponding to sedimentary cycles. Based on the chemical migration characteristics of each element, the characteristics of the depression in the southeast of Ordos Plateau and the location of monsoon sand area in the study area, the effects of Al2O3, TFe, Mn, TiO2, K2O, MgO, CaO and Na2O Relatively lower, with dry and windy climate and the impact of a large number of quartz immigrants related to the relative migration of the lacustrine facies and paleosol SiO2, Al2O3 and other aggregates showed the same trend, with the warm and humid climate stability under the elements of Al2O3, TFe, Mn, TiO2 and the unstable elements K2O, MgO, CaO and Na2O are all related to the special relatively closed lowland from the surrounding terrestrial surfaces. The study shows that the 27 elemental change cycles of the Salawusu River Basin since 150 kaB.P. Have an genetic relationship with the multiple alternations of the Asian winter monsoon in the Mu Us Desert triggered by the climatic fluctuations in the Northern Hemisphere glacial-interglacial periods.