Why is Wulong Karst special
Situated in China’s southwest Chongqing, Wulong Karst is an important part of South China Karst. It was named as a world natural heritage by UNESCO in 2007. Compared with Stone Forest in Yunnan and Libo Karst in Guizhou, Wulong Karst is located in a relatively remote area away from the impact of human activity. Therefore, Wulong Karst retains its original features of karst landforms, hence its outstanding universal value.
As a cluster of several karst landscapes, consisting of gorges, natural bridges, caves, eroded dolines, shafts and underground streams, Wulong Karst is a valuable treasure that nature created. Three major karst landscapes are named as Lotus Cave, Three Natural Bridges and Houping Giant Doline. These karst landforms developed in the carbonate rocks, vividly recording the development and evolution of karst terrain in the Three Gorges area since Pleistocene Era. They are the three representative karst landforms, developing under the condition of intermittent uplifting movement of the earth.
Wulong Karst Highlights
Each of the three karst landforms has its own distinguished characteristics. The Lotus Cave abounds with various karren sediments. The limestone sediments not only present wonderful sceneries, but also offer great significance in scientific study; the Three Natural Bridges constitute the largest natural bridge cluster in Asia. The natural karst bridges are quite high and grand, a sight rarely seen anywhere in the world; Houping Giant Doline is the prime example and the largest doline cluster formed by erosion in the world.
Three Natural Bridges
Three Natural Bridges feature three natural karst bridges: Tianlong Bridge, Qinglong Bridge and Heilong Bridge. The three natural karst stone arch bridges constitute the largest natural bridge cluster in Asia with an average height of over 200 meters, and an average span of over 200 meters.
Tianlong Bridge is about 200 meters in height, 100 meters in width. It spans 450 meters, and has two arches from south to north. The south arch was also called Mihun Cave. The northern arch is a passage; Qinglong Bridge is about 350 meters high, 150 meters wide, and spans over 400 meters. After the rains, a waterfall pours over the bridge and forms a mist. When the sunset reflects on the mist, a colorful rainbow emerges like a dragon ascending to the heaven; while Heilong Bridge has a deep and long arch passage, like a black dragon winding its way out. Heilong Bridge is also renowned for its four springs with tortuous trickles of stream.
The three natural bridges evolved due to tectonic uplift and the erosion by underground water. Some parts uplifted forming the bridges, and others collapsed to form karst pits. Therefore, the unique landscape of Three Natural Bridges enclosed with Two Pits is solely nature’s creation. It is a rare geological wonder and a delight for eco-tourists.
Lotus Cave is a large limestone cave, formed in the carbonate rocks of Cambrian-Ordovician Period. Lotus Cave is abundant with various speleothems, which shape the dazzling karst landscapes. Located on the bank of the Lotus River, Lotus Cave is the only cave in China that was listed in World Natural Heritage List.
There are 100 species of sediment varying from carbonate to sulphur, and over 300 scenic spots in Lotus Cave. Covering an area of 11,000 square meters, the Glory Hall is the most spectacular. The magnificent stelae, stalagmites and stalactites are splendid and astonishing; the huge stone waterfall and curtain are 15 meters in width and 21 meters in height, which are quite grand; the palm-shaped stalagmites are as smooth as jade; the texture of the stalagmites is delicate and pure, which is rare elsewhere; and the red coral and calcite are very precious.
Lotus Cave was discovered by local farmers in 1993, and was opened to the public in June 1994. It was appraised by the Vice Chairman of World Cave Association as “one of the best caves open to tourists in the world”.
Houping Giant Doline
Houping Giant Doline is situated at Houping Town. It is the first doline cluster type of erosion discovered in the world. The Houping Giant Doline developed in the soluble limestone of Ordovician Period. It is an integrated karst ecosystem, consisting of gorges, dolines, shafts and underground caves, which demonstrate the various stages of the evolution of karst terrain. Based on the cause of formation, dolines can be divided into two types: collapsed dolines and eroded dolines. Collapsed dolines are common, while eroded dolines are quite rare. The Houping Doline cluster is the finest example of a rare eroded doline.
Covering a total area of 150,000 square meters, the Giant Doline is mainly composed of five smaller dolines. Located in a primitive forest, the five dolines well preserve the features of karst landforms. The cylindrical dolines are huge, measuring about 300 meters both in diameter and depth. At the bottom of dolines, there are spacious underground caves, in which larger dolines hide. Among the five dolines, Qingkou Doline is the most typical. It has integrated morphologic features, providing strong evidence of geological evolution. The pithead takes an oblong shape, and has a depth of about 300 meters. From a view from the bottom of the doline, the steep walls extend to the vault of heaven.
Endowed with so many wonders by nature, the Giant Doline cluster is an ideal place for scientific study of the geological evolution as well.