Minecraft wiki entry for carver, associated text:  config:Configuration values for the carver.
 probability: The probability that each chunk attempts to generate this carver, must be between 0 and 1.
 y: Height provider. The height at which this carver attempts to generate.
Height provider[show]
 yScale: Float provider. Vertically scales the carved area.
Float provider[show]
 lava_level: The vertical anchor where lava begins to generate.
Choices for a vertical anchor[show]
 aquifers_enabled: If true, aquifers will be generated.