再论察尔汗盐湖矿床的构造演化

A REDISCUSSION ON THE STRUCTURAL EVOLUTION OF SALT DEPOSITS IN QARHAN SALT LAKE

柴达木盆地察尔汗盐湖的成盐建造可分为:浅部构造层(Q_2—Q_4);中部构造层(R—Q_1);深部构造层(K以前)。其成盐作用可分为:泛湖阶段(Q_1);盐渍阶段(Q_2);盐沼阶段(Q_3);干盐湖阶段(Q_4)。从地层建造、变形特征、继承关系、富盐程度讨论了构造层次的生成关系。由成盐物质侧向补给的盐筛效应、垂向补给的构造膜效应讨论了构造的成盐规律,并确立了盐湖不完全对称地堑式的沉积模式。

The structure of salt deposits in the Qarhan Salt Lake has been studied comprehensively from the available data. According to the structural characteristics, the salt-forming formations in the lake can be divided into: 1) epi-structural layer (Q2-Q4), 2) mid-structural layer (R-Q1), and 3) deep-structural layer (pre-Cretaceous). The saltforming process in the Qarhan Salt Lake may be distinguished into 4 stages: (1) overflow-lacustrine stage (Q1), (2) salt soil stage (Q2), (3) salt marsh stage (Q3), and (4) salt playa stage (Q4). From the data on the stratigraphic formations, deformation features, inherited relation and salt abundance, the author deals with the genetic relationship between the structural layers, and also the structural regularities for salt-forming by the salt sieve effect of lateral feeder and structural film effect of vertical feeder of the salt-forming materals. The author sets up an asymmetric graben-type sedimentary pattern for the Qarhan Salt Lake.