Quse hot spring, surrounded by green travertine, in Xizang (Tibet)

The Quse Hot Spring is located in the Qiangtang National Nature Reserve on the northern Xizang (Tibetan) Plateau, at an elevation of 4,740 meters above sea level. The spring outlet temperature reaches 72.8°C, and the water is of the NaHCO₃ type. The helium isotope ratio of the gases is 0.22 Rc/Ra, indicating that the helium is mainly derived from crustal sources, with a minor contribution from mantle-derived helium. Travertine deposits across the Qinghai–Xizang Plateau are typically dominated by white and brown calcium carbonate formations, while green travertine makes the spring unique visual appearance.