摘要
依据已有研究成果和最新调查资料,在综述沙漠湖泊与高大沙山研究进展及存在问题的基础上,深入探讨了巴丹吉林沙漠湖泊水的补给来源、补给模式及高大沙山的形成机理.结果认为,沙漠湖泊水和地下水的补给来源不是当地降水和周边雅布赖山-北大山的降水形成的地表洪水,而是南部青藏高原(包括祁连山)现代大气降水、冰雪融水、高原湖水的远源补给.补给模式为高原富含CO2气体和Ca CO3的入渗水,通过深大导水断裂通道形成的区域地下水流循环系统,源源不断地自南向北运移到沙漠地带,地下水在通过沙漠湖泊区弧形"叠瓦状"垂向导水构造断裂向上越流过程中被广泛分布的岩浆岩加热,沿断层溢出地表形成湖泊群,同时导致水中CO2的释放和Ca CO3的沉积,形成钙华体.高大沙山的形成机理是深层地下热水向上越流补给了沙漠覆盖区,在承压水头以下形成鼓丘状的沙漠地下水,承压水头以上,水蒸汽继续向上运移并被凝结在沙粒表面,未被吸附凝结的热水蒸汽继续向上运移并被吸附在新沉积的沙粒表面,形成湿砂层并接受更新的沙粒沉积,如此反复循环,则沙丘高度不断增加,逐步形成高大的固定沙山.
Based on the former research results and latest investigation materials,this paper summarizes the research process and existing problems about desert lakes and megadunes and further exploring the supplying resource and mode of the lakes in the Badain Jaran Desert. It comes to a conclusion that the supplying source of both desert lakes and underground w ater is neither by local precipitation or flood resulting from precipitation on the peripheral Jacob Lai mountains-North mountains,but rather feed by southern Tibet Plateau including Qilian M ountain through atmospheric precipitation,ice thaw ing and far-source plateau lakes feeding. The supplying mode is the infiltration w ater rich in CO2 and Ca CO3 goes through the raptured pipe w hich forms underground circulation system. It delivers the w ater continuously from south to the north, desert zone. When the groundw ater arriving at the desert lake zone,it w ill be heated up by the vertical conductive structure shaped like＂laid tile＂arc which is made from magmatic rock. Then the water overflows from the faults to form lake group,meanw hile it leads to the release of CO2 and Ca CO3 deposition forming calcium cementation layer. The mechanism of formation of megadunes is that w hen underground w ater in deep depth goes upw ards to feed the desert covered zone the drum shaped desert underground w ater is formed beneath artesian head and above the artesian head,w ater vapor keeps going upw ards and stays at the surface of sand particles and the uncoagulated hot vapor continues going upw ards and is absorbed by sand particles of new deposited sand to form w et sand receiving renew ed sand particles deposition. Thus the circulation repeating leads to the grow th of sand dune and finally the megadunes are formed.
出处
《冰川冻土》
CSCD
北大核心
2015年第3期783-792,共10页
Journal of Glaciology and Geocryology
基金
国家自然科学基金重大研究计划项目(91225302)
中国科学院重点部署项目(Y322G73001)资助
关键词
沙漠湖泊
高大沙山
地热
地质构造
巴丹吉林沙漠
青藏高原
desert lakes
megadunes
geothermy
geological structure
Badain Jaran Desert
Qinghai-Tibet Plateau
