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天山北坡海拔2400～700 m间不同高度的地貌面上分布大片风成黄土,是准噶尔盆地古尔班通古特沙漠的同源异相沉积.黄土在沙湾和石河子一带最厚,其中沙湾清水河出山口河流最高阶地上71m厚的黄土发育9大层浅褐色古土壤,其层序结构和特征与黄土高原古土壤非常相似.古地磁测定表明B/M界线位于 69.5 m深处的黄土 L8底,推测剖面底部年龄约 800ka前,指示准噶尔盆地极端干旱气候和现代古尔班通古特沙漠雏形最迟大致于同时形成.高分辨率粒度古气候记录揭示出距今约650和500ka年前有两次显著的干旱化增强和沙漠扩大,然后逐步增强最终形成今天的环境格局.这些干旱化和沙漠扩大事件与中更新世全球气候巨大变化基本同步.亚洲内陆沙漠和干旱区大范围变化所导致的巨大环境效应可能是全球气候变化和中更新世系列气候事件发生的重要驱动力.
In the northern slope of Tianshan Mountain, there are large amounts of aeolian loess distributed on the geomorphic surfaces with altitudes of 2400-700 m above sea level, which are the same-sourced and heterogeneous sediments of the Gurbantunggut Desert in the Junggar Basin, where the loess is the thickest in Shawan and Shihezi, Nine layers of pale brown paleosol are developed in the 71m thick loess on the highest level of the river from the Qingshui River estuary, and the sequence structure and characteristics are very similar to the paleosol in the Loess Plateau. Paleomagnetism measurements indicate that loess with B / M boundary located at depth of 69.5 m L8 bottom, presumed that the bottom of the section before the age of about 800ka, indicating that the extreme arid climate in Junggar Basin and the prototype of the modern Gurbantunggut desert formed roughly at the same time at the same time. High-resolution grain paleoclimate records reveal about 650 and 500ka years ago There have been two notable increases in aridification and desert expansion in the past and the gradual increase in the final formation of today’s environmental landscape.These aridification and desert expansion events are basically in sync with the tremendous changes in the global climate in the mid-to late Pleistocene Asia Inland Desert and Arid Regions Extensive The huge environmental effects caused by the changes may be a significant driver of the global climate change and the Middle Pleistocene climatic events.