萨拉乌苏河流域第四纪地层及古环境研究综述

Review of Quaternary Strata and Paleoenvironment on Salawusu River Valley in North China

萨拉乌苏河流域位于我国毛乌素沙漠—黄土高原过渡带,对东亚夏季风和冬季风驱动的古环境波动及全球冰期—间冰期旋回有良好的地质记录。流域内河湖相和风成相沉积交错互层,发育有华北地区晚更新世标准地层——萨拉乌苏组,并含有河套人化石、萨拉乌苏动物群和丰富的文化遗迹。从其发现定名至今,就得到了古人类学家和地质学家的广泛关注。研究表明,流域内出露的第四纪地层主要包括晚更新世萨拉乌苏组和城川组,全新世大沟湾组、滴哨沟湾组和范家沟湾组,这与古气候代用指标所反映的沉积环境有很好的阶段响应。本文通过对滴哨沟湾和米浪沟湾剖面研究进展的回顾和总结,认为在建立精确的地层年代序列,重建末次间冰期以来的高分辨率古环境历史,明确萨拉乌苏动物群及文化层的归属和厘定萨拉乌苏组沉积相等方面有待更深入的研究。

The Salawusu River Valley is located in the transitional zone between the Mu Us Desert and the Loess Plateau, and in the northern marginal area of the East Asian Monsoon. de Chardin and Licent （1924） discovered a paleolithic industry and many fossil specimens in the Salawusu River Valley （or Sjara-osso-gol） in which they found the first fossil evidence （＂the Ordos tooth＂） of paleolithic man in Asia. From then on, the research developments of the Salawusu River Valley get much attention and affirmation from the paleoanthropologists and geologists. In this paper, writers put emphasis on both of the Dishaogouwan section and Milanggouwan section, and reviewed the study history on Quaternary stratigraphy and paleoclimate. The strata in the river valley are made up of interlaced fluvio-lacustrine facies and aeolian facies, consist of Salawusu fauna and many geological vestiges. Previous studies indicate the strata contain sedimentary sequences from the last glacial period to the postglacial period, including the Salawusu Formation （150~70 ka BP） which is the typical Late Pleistocene strata sequence in North China, the Chengchuan Formation （70~11 ka BP）, the Dagouwan Formation and the Dishaogouwan Formation （11 ka BP）. The sedimentary cycles respectively correspond to the paleoenvironment variations in the glacial-interglacial terms, which is explained by the changes of the East Asian Summer Monsoon and Winter Monsoon. Climate proxies help us to confirm these ideas. At the same time, there are still some excited problems and suggestions： （1） the correct and credible chronostratigraphy should be established quickly, especially on the Salawusu Formation; （2） detail study on sedimentary facies may help us to get the high-resolution paleoclimate records which need more accurate data by different ways; （3） whether there existed a paleolake in the southeast margin of the Mu Us Desert during the period between 40 ~30 ka is still an interesting question; （4） some divergent views, such as the different translations of the ＂Ordos Man＂ and the issue of the time scale of Salawusu fauna and cultural layer, need to be unified as soon as possible. Further research of Quaternary strata and paleoenvironment has great significances.Combining the records of the Salawusu River Valley with some recent discovery on adjacent regions is indispensable.