石笋是洞底由下而上生长的钟乳石，是洞顶滴水在洞底沉淀形成的形如春笋的次生化学沉积物。敢沫岩洞穴内的石笋群，呈典型的棕榈状，20m以上的石笋多达26根，质地如玉，在全国范围内的洞穴实属罕见，是洞厅较高、水流流速较快时由滴水和飞溅水综合作用形成的，是溶洞内协同沉积的典型代表。

Stalagmites grow upward at the bottom of the cave. They are secondary chemical deposits shaped like bamboo shoots in spring formed by dripping water from the top of the cave. The stalagmites in Ganmoyan cave are typical palm-shaped. There are as many as 26 jade-like stalagmites over 20m, which is rare in caves all over the country. Stalagmite group is a typical representative of synergetic deposition in the cave formed by combined actions of dripping water and splashing water.