保存农乐杂卤石矿床的水文地质条件

农乐杂卤石矿床是20世纪80年代在我国发现的埋藏在地下的第一座硫酸钾盐矿床。杂卤石作为一种含硫酸钾的非金属矿物，常温下即能溶于水；在形成矿床后，除了要有一个适宜的构造环境外，还得有一套不透水的盖层和底板的保护，避免地表水、地下水(淡水)的渗透、淋滤、潜蚀、溶解，才能较好地保存下来。保存农乐杂卤石矿床的水文地质条件包括：有利于地表水自然排泄的地形地貌，矿床顶底板都是隔水层，地表水、地下水不能进入矿床；无沟通地表水地下水与矿床水力联系的断层；含水层具承压性质，有良好的补给、迳流、排泄的自然循环条件，地下水不能对矿床充水。

Hydrogeologic conditions for preservation of the Nongle polyhalite ore

The Nongle polyhalite ore is a sulfate potassium ore which was first found in the subsurface in China in the 1980s. Since the polyhalite solves in water under ordinary temperature, a suitable structural environment is needed to preserve a polyhalite ore after the ore was formed. A pervious confining layer is usually necessary to prevent the ore from being percolated, eroded and solved by surface water and groundwater. Hydrogeologic conditions for preservation of the Nongle polyhalite ore include:topography and physiognomy conditions suitable for surface water to drain naturally, a top confining aquiclude which prevents surface water and groundwater from entering the ore, a lack of faults which connect the surface water, groundwater and the ore. Aquifers, if any, must be artesian, and groundwater in the aquifers cannot fill the ore.