 The rock strata are 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 via the Bailong River, part of the Yangtze River system.Jiuzhaigou's best-known feature is its dozens of blue, green and turquoise-colored lakes.