{
  "type": "minecraft:range_choice",
  "input": {
    "type": "minecraft:noise",
    "noise": "minecraft:gravel",
    "xz_scale": 3,
    "y_scale": 0
  },
  "max_exclusive": 0,
  "min_inclusive": -1,
  "when_in_range": "rfi:aquifer/lower",
  "when_out_of_range": "rfi:aquifer/upper"
}