【摘要】 <正> 一、引言盐类沉积是由地表浓缩的卤水经过沉淀作用而形成的。它的成因与受局限的盆地和强烈的干旱气候有关,通常被认为是一种特殊地质条件下的产物。随着地质工作的发展,蒸发岩的产出时代不仅自显生宙以来的每个纪都有,而且几乎遍及每个世。以石膏(硬石膏)为例,其分布时代可上溯到元古代,甚至在南非(阿扎尼亚)的翁弗尔瓦赫特群(Onverwacht Group)中可能还有更多还原

【Abstract】 The major effects of the geomorphology of basins on saline deposits were for a long time neglected. In fact, many saline basins show the high mountain-deep basin feature, which is not only exemplified by some modern saline basins but also by some famous Meso-Cenozoic or even Paleozoic salt deposits which have been proved to be products of evaporation of brines in such an environment.The difference between the elevations of the deep basin and its surrounding mountains may reach a height of 1000—2000 m or even more and the differences in local climate, vegetation and hydrological conditions are prominent as well, so the surrounding mountains are favourable for the supply and transportation of salts, while the depression in a basin is favourable for the concentration and deposition of salts. Furthermore, the high mountain-deep basin geomorphology is usually controlled by deep fractures, which also facilitates the supply of salts from the depth, migration of brines in a basin and differentiation and concentration of salts.As multiple rejuvenation of fractures controlling the high mountain-deep basin geomorphology intensifies the landform, the saline basin is not stable for a long period. Recent studies of rift valleys show that saline deposits are precipitated in a certain stage of development of various rifts and are a characeritstic formation originating under an arid climate as well as the product formed in the process of plate motion. So it is closely related to tectonic movement and magmatic activity. The idea proposed in this paper is conducive to the solution of certain long-standing controversial problems on the genesis of salts; it has provided the basis for formulating a new genetic model of salt deposits and meanwhile opened up a new channel for the study of the temporal and spatial regularity governing the formation of salt deposits.更多还原