dong Wangmadong -

Wangma Dong (GX/Nd/1)
Guangxi, Nandan County, Dong Tung Ping
N 25° 17’ 6,34’’ E 107° 38’ 7,09’’
Altitude: 809 m a.s.l.
Type of research: physical-chemical analyses, biological
Exploration: Guizhou 2004, Guizhou 2005 November
Surveyors: H. Bertasi, R. Zorzin (10 Nov. 2004), H. Bertasi, G. Di Silvestro, G. Gozzo, R. Zorzin (8 Nov. 2005)
Cave description:
The entrance to the cave is suspended on the upper rim of a doline at the base of a karst cone; it is easily reached from the road. The cave begins with a wide inactive gallery a few hundreds m long which leads to a lower level of galleries with a shaft-waterfall of about 10 m. The gallery is almost free of debris, its diameter is never less than 10 m, and it represents the main structure of the cave. Towards the end of the gallery, the amount of clastic deposit increases until the gallery reaches a collapse room which is probably a tectonic intersection point (the opposite side of the collapse mound has not been explored). Passed this point, the gallery turns at more than a 90 ° angle, and the morphology becomes more and more tectonic: evidence of vertical cracks less than 1 m large, more or less filled with clastic material, which delimit the southern border of the karstic system for a length of about 300 m. We explored to a depth of about 30 m, most of it concentrated in the collapse rubble at the end of the main branch. This branch ends in an overflow gallery 200 m long, with a positive inclination, which leads back to the same elevation as the entrance; the clastic sediment is substituted here by 1 m thick layer of stratified clay and sand. More precisely, the lower layers are represented by yellow sand, the upper layers by darker sand, and a 5 cm thick layer of clay sealing the deposit. The gallery water inflow and outflow are provided by a small siphon, filled with mud at the time of our exploration, located in the lower section of the gallery.
At least two lateral branches start from the main gallery, but only one of them has been explored and surveyed. It is a phreatic conduit 200 m long with a diameter between 3 and 6 m, probably running on two levels which join through vertical connections. The presence of vegetal de-bris (including some large trees) in the first part of the gallery, and of some suspended pools, suggests he existence of another sinkhole (maybe represented by the doline outside the cave), active only during the rainy season. In fact, Wang-ma Dong develops on three levels: the higher one is the entrance, the intermediate one are the galleries surveyed in 2005, the third level is the active section, at the bottom of the doline; it is an overflow gallery that follows a vertical fracture. It was explored for about 7 m.; the phreatic surface of the karstic system emerges at the bottom. The local population informed us that during rainy periods the doline fills up with water, flowing also from the main entrance of the cave.
The analysis of the internal and external morphology of the cave allowed us to hypothesize that the cave was initially a sinkhole, and become an overflowing conduit only later.
(R. Zorzin)

Leonardo Latella, Roberto Zorzin : Caves explored during the scientific expeditions to China of the Museo Civico di Storia Naturale of Verona
Research in South China Karst - Memorie del Museo Civico di Storia Naturale di Verona - 2. serie - Monografie Naturalistiche 3-2008
Analyse : gkc-JPB
Results of the 13 expeditions organized by the Museo Civico di Storia Naturale of Verona to southern China. One-hundred-twenty-five caves were explored, for a total of more than 60 km in length. For each cave we list the progressive number, the cadastral number, the type of research conducted and a short description of the cave. Most of the caves are located in Guizhou Province, in Qianxi County. The hydrogeology, biology, geography and archaeology of the area were investigated during the scientific expeditions. 40 pages, No caves maps, 21 photos.

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