摘要
大、小柴旦盐湖盆地主要沉积亚环境有:洪冲积扇(裙)、沙坪、(盐)泥坪、盐盘、沙丘区和泉沼区。盆地内的各个亚环境大致呈同心圆状分布,但由于盆地四周的构造性质和活动强度不同,使得亚环境分布不完全对称。本文还通过对大、小柴旦盐湖盆地及其他实例的沉积分布特征分析,作了盐湖盆地沉积亚环境不同发育程度及分布位置的成因解释。最后探讨了研究盐湖盆地沉积亚环境的意义。
The Da Qaidam and Xiao Qaidam Salt Lake basins are two closed artesian basins, in which the main depositional subenvironments include diluvial-alluvial fans (aprons), sand flats, mudflats (including salt mudflats), salt pans, sand dunes and spring-swamp areas. The diluvial-alluvial fans (aprons)and sand flats are better developed on the side with a relatively large uplift amplitude of the surrounding mountains of the basins. Mudflats are better developed in the direction of recharge from the main rivers as there are more terrigenous fine clastic sediments in this direction. Brines in the salt basins are present on the side with the main source of water recharge of the salt pans. Sand dunes are mainly distributed at the ends of a sand flat and at both ends of the long axis of the basin. Springswamp areas are better developed in the direction of water recharge. The boundaries between the basins and their surrounding mountains are often subjected to the control of deep faultswhich serve as important passages along which spring water rises and brings ore substances. The various subenvironments in the Da Qaidam and Xiao Qaidam are largely distributed concentrically, but such distribution is not entirely symmetric, owing to the differences in the structural character and intensity of activity on the periphery of the basins. An integrated analysis has been made on the characteristics of the distribution of the depositional subenvironments in the Da Qaidam and Xiao Qaidam salt lake basins and other basins. According to this analysis the authors give a genetic interpretation of the different degrees of development and distribution of the depositional subenvironments of the salt lake basin and discuss the significance of the study of the depositional subenvironments of the salt lake basins.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第3期220-228,共9页
Geological Review
