Liangshan Stone Swallows

　　　　Liangshan Mountain is located about thirty Chinese miles west of Hanzhong City. It is a peak formed from seabed sedimentary rocks through crustal movements. The rock strata structure has been quite well preserved, reflecting changes in the earth’s crust and providing important specimens for geological research.

　　　　Stone swallows are fossils of ancient brachiopods, a type of marine animal. They were deposited on the seabed along with silt and sand, and under the pressure of seawater, turned into sedimentary rock. Later, due to crustal movements, the seabed rose and became land, which then folded to form mountains. As the mountain rocks weathered, they turned back into silt and sand, and the animal fossils separated from the surrounding sediment, eventually emerging above ground. The stone swallows commonly seen today are a type of such fossils.

　　　　As far back as 30 million years ago during the Paleozoic era, Hanzhong was still covered by a vast ocean. Therefore, these fossils often appear in Liangshan Mountain, which was formed from seabed sedimentary rocks. In Su Dongpo’s “Record of the Joyful Rain Pavilion,” there is a description: “When the wind rises, the Shangyang bird dances; when rain is coming, the stone swallows fly.” “Liangshan Stone Swallows” have become a unique and rare marvel of Hanzhong. The winds and rains over Liangshan have also been regarded as a wondrous natural phenomenon.