Geology and Hydrology
Jiuzhaigou's landscape is made up of high-altitude karsts shaped by glacial, hydrological and tectonic activity. It lies on major faultlines on the diverging belt between the Qinghai-Tibet Plate and the Yangtze Plate, and earthquakes have also shaped the landscape. The rock strata is mostly made up of carbonate rocks such dolomite and tufa, as well as some sandstone and shales.
The valley includes the catchment area of three gullies (which due to their large size are often called valleys themselves), and is one of the sources of the Jialing River, part of the Yangtze River system.
Jiuzhaigou's best-known feature is its dozens of blue, green and turquoise-colored lakes. The local Tibetan people call them "Haizi" in Chinese, meaning "son of the sea". Originating in glacial activity, they were dammed by rockfalls and other natural phenomena, then solidified by processes of carbonate deposition. Some lakes have a high concentration of calcium carbonate, and their water is very clear so that the bottom is often visible even at high depths. The lakes vary in color and aspect according to their depths, residues, and surroundings.
Some of the less stable dams and formations have been artificially reinforced, and direct contact with the lakes or other features is forbidden to tourists.
Read more about this topic: Jiuzhaigou Valley