摘要
为了解钾盐矿层形成及后期改造的地质条件,用于钾盐勘查与找矿。文中分析了物质来源、气候和内外动力条件对钾盐矿床的形成与改造。万象盆地含盐系地层为新近系古新统的塔贡组,从下至上由三个沉积旋回组成,每个沉积旋回从下至上由盐岩层—泥岩层组成。钾盐工业矿层赋存于塔贡组下岩性段下亚段石盐层的上部,是钾盐矿找矿的目标层。在中岩性段下亚段石盐层的上部,局部可见薄层钾盐矿层,不具工业价值。认为炎热、干燥的气候条件及海水的持续补给是钾盐矿形成的基本条件;受内外动力条件的影响,成矿早期的地壳升降影响富钾卤水的局部富集及沉积成矿的位置;成矿晚期地壳的升降破坏矿层的稳定性;在盐背斜核部(核部及其两翼)易形成厚度较大的钾盐矿层;而在地壳相对抬升部位,已形成的钾盐矿层有被剥蚀的可能。
By understanding the geological condition formed by potash ledge,the potash ore exploration can be guided. This paper analyses the material source and climate condition of the sedimentary,salt forming and mineralization,and the transform of seam from endogenic and exogenic geological processes,etc. . The salt - bearing strata in Vientiane Basin is Paleocene - Tagong of the Neogene, and it is made up of three depositional cycle from the bottom. Each depositional cycle is madeup of gypsum - mudstone layer from the bottom. The potash industrial seam lies on the upper part ofthe halite bed in the lower part of lower lithologic section,which is the target zone of potash mineprospecting. thin layer of potash ledges in the upper part of the halite bed in the lower part of middlelithologic section is visible,but has no industrial value. The hot,dry weather conditions and thecontinuous supply of the seawater are the basic conditions of potash deposit formation. Because ofthe influence of the endogenic and exogenic geological processes conditions,the crustal rise and fallin the early ore - forming caused the local enrichment of potassium - rich brine and the location ofthe sedimentary mineralization. The crustal rise and fall in the late ore - forming destroyed the stability of the seam. At the core of salt anticline （ nuclear and its two wings） ,large thick potash deposits tend to form,but at the crust relative uplift area,the formed potash deposits are prone to denudatio.
出处
《青海大学学报（自然科学版）》
2017年第1期29-37,100,共10页
Journal of Qinghai University(Natural Science)
关键词
钾盐矿床
万象盆地
形成
改造
potash deposit
Vientiane Basin
formation
reconstruction
