{
  "type": "minecraft:spring_feature",
  "config": {
    "hole_count": 1,
    "requires_block_below": true,
    "rock_count": 4,
    "state": {
      "Name": "minecraft:lava",
      "Properties": {
        "falling": "true"
      }
    },
    "valid_blocks": [
      "minecraft:blackstone",
      "basalt",
      "smooth_basalt"
    ]
  }
}