巴丹吉林沙漠第四纪研究评述与讨论

Review and Discussion about the Progress of Quaternary Research of the Badain Juran Desert,China

近20年来巴丹吉林沙漠第四纪研究倍受地学界的关注,取得了较大的进展,但在一些主要问题的认识和结论上,分歧和争论极大。在综合分析大量研究成果的基础上,对第四纪研究进行了系统的评述和讨论,指出了这些研究中存在的问题、以及出现分歧和相互矛盾的原因。在沙漠形成的时代上,现有的研究主要是对沙漠部分地区的地层断代和沙丘浅部的测年,尚没有系统的工作,为此这里特别对影响沙漠时代研究的几个主要因素进行了详细的讨论。关于高大沙山和其间湖泊的形成机制,前者有多因素理论和地下水理论,后者有沙山间负地形理论说和断裂构造理论。尽管这些理论的依据和手段主要是运用不同的地球化学元素来示踪水源,但得出的结论迥异。通过对这些结果的分析,认为彼此的适用性还需进一步的证实。湖泊水源争论的原因主要是缺乏对沙漠地貌、下部地质、沙山钙结层和植物根套的综合研究所致,沙漠下部地质的进一步研究是解决这些问题的关键。在沙漠气候及其演化的研究上,西风环流和东亚季风对沙漠的形成和演化的影响程度还不清楚。最后对巴丹吉林沙漠的未来研究进行了展望。

Quaternary research on the Badain Juran Desert has been paid great attention to by geoscientists, and many achievements have been achieved since recent 20 years. However, there are still some disputes and divergences about the main issues and conclusions. In this paper, the achievements about the Quaternary research of the Badain Juran Desert are systematically summarized and commented after analyzing the conclusions, and some problems in these conclusions and contraction causes are discussed. The systematical research work about the geologic periods of the desert formation is insufficient because the current achievements in scientific research are based on the local stratum dating and shallow-dune dating. The main factors affecting the study results of the geologic periods of the desert formation are discussed in detail. Formation mechanisms of magadunes have multi-factor theory and ground water theory. The conclusions based on the formation mechanism of high sand dunes and inter-dune lakes and the theories of inter-dune negative landforms and fracture structure are very contrary although the different chemical elements are generally used to trace water sources. After analyzing these achievements, it is considered that their applicability needs to be validated, the disputations are caused by the insufficiency of integrated studies on the morphologic and belowground-geologic features, dune caliche and plant roots in the desert. It is the key to further understand these issues. For the desert climate change, the effects of westerly monsoon on the formation and evolution of the desert are not understood yet. At last, the ran Desert in the future is prospected. circulation and East Asian research of the Badain Ju-ran Desert in the future is prospected.