沙尘暴形成史初步研究——中国沙漠几个典型地质学记录的实证

以位于沙漠黄土边界带的榆林、阿羌和米浪沟湾地层剖面为典型例证 ,讨论了 110 0kaBP以来中国沙漠沙尘暴的形成、发展和演化过程。提出在过去的 110 0ka中该区总共记录了 4 2个沙尘暴时期 ,并与 4 1个间沙尘暴时期构成比较连续且交替进行的一系列沉积演化历史。其中 ,最强烈的沙暴期发生时间大致在 6 2 0kaBP和 6 80kaBP前后 ,最温暖的间沙尘暴期出现在 5 90～ 5 0 0kaBP和15 0～ 70kaBP。研究认为 ,110 0kaBP以来因沙尘暴期与间沙尘暴期交替出现而形成的沉积旋回 ,是自那时以来在冰期、间冰期气候波动影响下冬夏古代季风相互对峙、交替演化形成气候旋回的结果

A PRELIMINARY STUDY ON THE FORMATION HISTORY OF SAND-DUST STORM-TAKING THE TYPICAL GEOLOGY RECORDS IN DESERT OF CHINA AS A DEMONSTRATION

Taking the stratigraphical sections of Yulin, Aqiang and Milanggouwan sections located in the desert and loess transitional belt as typical examples, we have discussed the formation of the sand dust storm in the desert of China since 1 100 ka B P and its development and evolutionary processes. It is put forward that in the past 1 100 ka, there were historical records of 42 periods of sand dust storms in the desert; these periods of sand dust storms, together with the 41 periods of inter sand and dust storms, constituted a history that comprised a series of comparatively continuous and alternately sedimentary and evolutionary processes; the strongest periods in sand dust sdtorms occurred ca. 620 ka B P and 680 ka B P , and the optimal warm stages in the inter sand and dust storm periods appeared in 590～500 ka B P and 150～70 ka B P. The study result suggests that the sedimentary cycles formed by the alternations of sand dust storm and inter sand and dust storm periods were radically induced by the climate cycles that were formed by the mutual growth and decline, and the confrontation and evolution between the winter and summer monsoon under the influence of the climate fluctuations over the glacial and interglacial periods.