摘要
云南澄江上震旦统白云岩,其白云石有序度与沉积和成岩环境有关。浅滩相的颗粒白云岩,其白云石有序度为0.857,MgCO_3=50.574%Sr/Ba=0.206,小于1,为混合水白云石化模式产物;潮坪-泻湖的藻白云岩,白云石有序度也高,为0.922-1,MgCO_3=50.230-50.912%,Sr/Ba=0.277-0.313,小于1,也是有淡水参加作用的库龙白云石化模式产物;只有萨布哈的膏质白云岩,白云石有序度低,为0.588,Sr/Ba=2.475,大于1,CaCO_3≈MgCO_3(无序排列),系蒸发泵白云石化模式产物,震旦系白云石也有无序的。
The order degree of dolomite is related to sedimentation and diagenetic environment. Forgrain dolostone of shoal facies the order degree of dolomite δ is 0.857, MgCO_3=50.57%, Sr/Ba=0.206, less than 1. This type of dolomite is suggested to be product of mixed water dolomitization.For algae-dolostone of tidal flat and lagoon facies. δ=0.922-1. MgCO=50.230-50.912%.Sr/Ba=0.277-0.313, also less than 1. Dolomite is developed on the Coorong dolomitizationmodel, but with fresh water effect. The Sabkha type gypsiferous dolomite has the lowest orderdegree, δ=0.588,Sr/Ba=2.475, more than 1. CaCO_3≈MgCO_3 (disorderly arranged). This typeof dolomite is the product of evaporative pumping.Disordered dolomite is also observed in the Siniandolostone.
关键词
上震旦统
白云岩
岩石
有序度
Upper Sinian
dolomitization model
order degree
shoal
tidal flat
lagoon
Sabkha
