As water flowed down the hydraulic gradients toward the Green River many canyon style passages were formed, while other more elliptical passages formed under phreatic conditions. Either while water levels where higher or during high precipitation events when channels were flooded.
Northern Vietnam
Immense rooms in caves from Halong Bay, monsoonal climate aids in dissolution process.
Fenglin- notches from wave erosion.
Exposed limestone strata at Halong Bay, tilted beds indicate tectonic activity.