Lichenometric Dating, Excavated Age and Cause on Huashan Grottoes
皖南花山石窟群开凿年代地衣测年及成因

According to 96 data of the maximum inscribed circle diameter of Rhizocarpon geographicum lichen on the ancient bridges and buttress, toriis, tombstones, folk house, foundations and the wall of grottoes entrances in the Huashan Grottoes area, the carving time of the grottoes is likely 515-370 aBP, that is, in the middle and late Ming Dynasty (1477-1632 AD). The lithological comparisons of the grottoes and the surrounding around ancient architectures, historical materials record, and the ages of ancient China relics in the grottoes are researched. All of the above evidences can prove the lichenometric dating result. The lichenometric dating was measured on the grottoes entrances (inner grottoes has no sunlight, so the lichen can not grow), therefore, it can be inferred that the excavation to the inner grottoes can be possibly dated back to the Qing Dynasty.