A basin where rock layers have been folded and in which permeable rock which has trapped water is sandwiched between impermeable layers is referred to as

The basin you are describing is called an "artesian basin." An artesian basin is a geological formation where permeable rock, such as sandstone, holds water that is trapped by layers of impermeable rock, such as shale. This water is under pressure because it is confined within the layers of rock, so when a well is drilled into the basin, the water will naturally flow to the surface without the need for a pump. Imagine a water balloon that is squeezed between two flat surfaces. The water inside the balloon is trapped and under pressure, just like the water in an artesian basin. When you poke a hole in the balloon, the water will flow out because of the pressure, just like the water in an artesian well. In summary, an artesian basin is a geological formation where water is trapped between layers of rock and is under pressure, allowing it to flow naturally to the surface without the need for a pump.