Often, rimstone is covered with small, micro-gours on horizontal surfaces. Rimstone basins may form terraces that extend over hundreds of feet, with single basins known up to 200 feet long from Tham Xe Biang Fai in Laos.
Rimstone often has tiny micro-gours on its horizontal surfaces. Rimstone depressions can form terraced structures that span over hundreds of feet, and some basins reach lengths of up to 200 feet in Tham Xe Biang Fai, Laos.