Travertine Mineralogical Characteristics and Spatial Distribution in Huanglong, China, a World Natural Heritage: Derived from Late Pleistocene to Early Holocene Glacial U-Shaped Valley Carbonate Deposits

In the long and complex process of geological evolution, the rise of the Himalayan movement and the strong Quaternary glacial movement 400,000 years ago have shaped the highly distinctive travertine landform landscape of Huanglong, China. The overflow of karst water in the high travertine layer has formed magnificent waterfalls and wonderful karst caves as well as the world's largest open-air travertine beaches and pools. The unique travertine landscape has entered the public's vision. The travertine landscape composed of rare geological relics such as pools, terraces, beaches, waterfalls, and karst caves is like a gorgeous garland on the eastern edge of the Qinghai-Tibet Plateau, playing a pivotal role in China and even the world. The mineralogical characteristics and development level of Huanglong travertine were studied by means of hydrogeological survey, UAV aerial survey, and rock and mineral analysis. The length of Huanglong Trench is 3.6 km, with an average thickness of 17.8 m, and the thickest part is 31.9 m at the front of Pengjing pool. Due to the strong alteration of superficial plants, the main vertical structure is diversified, with porous travertine, dense travertine, and detritus travertine. Huanglong travertine was born in the late Pleistocene to early Holocene of the Quaternary. The deep carbonate rocks were deposited on the surface through a water cycle. The mineral composition is mainly calcite, and the purity of CaCO₃ is generally over 95%. The research results have initially revealed the mineralogy characteristics and landscape spatial distribution of travertine in Huanglong World Natural Heritage.