Stage 1:

Rainwater (purple) moves downward through faults or fractures in the rock and mixes with briny water (blue) deep in the rock.

Stage 2:

When the two waters mix, the chemistry changes and allows the water to dissolve the rock.

Stage 3:

The mixing zone becomes deeper in the rock as uplift occurs. The upper part of the cave drains and becomes air-filled while cave development is still occurring below.