Grottes et karsts de Chine... Sur les traces de Xu Xiake
Gebihe 89 Contents

Chapter 5: Karsts and caves of Wufeng county (Hubei)


Résumé -Abstract - Zusammenfassung -:Located in the south west of the Hubei province, the mountainous region of Wufeng culminates at 2320 m and shows morphology with qiufeng-ouvala, qiufeng-polje and deep canyons. The SW-NE folds are composed of 2000-metre-thick limestones and dolomites, from Cambrian to Trias. The mountain subtropical climate, with a pronounced continental touch, is characterized  by an important thermic amplitude (1,7°C in January, 24°C in July at 600 m a.s.l.). The precipitation  amount to 1400 to 1600 mm/year. The forests cover 70 % of the county (with some climacteric forests at the border of Hunan),  cultures 10 % (tobacco, tea, maize, wheat....).
 In twelve different caves, 27 km of passages were surveyed. The Longdong system, near Wufeng, is composed of two main caves:  the Dadong sinkhole (9,7 km long), which begins at a 100-metre-high entrance at the end  of the blind canyon of the Songjiahe river, and the Longdong resurgence (5,7 km). Further to the East, in the mountains, the system of General's cave, East Pitch and West Pitch have been explored. General's cave is a 1,95 km long tunnel-cave to which a labyrinth of passages is connected. The East Pitch and West Pitch are active sinkholes in the bottom of a temporary flowing valley. They are the entrances of a 382 m deep and 5 km long "alpine" system, with pitches, meanders, rivers and potholes. Remarkable sediments were observed: speleothems (Thenardite, gypsum speleothems) and a rhythmic settling with red and grey varve and pebbly beds, 25 m high, testify to a soil withdrawing in terms of a paleoclimatic sequence.

Keywords: qiufeng, ouvala, polje, canyon, blind valley, sinkhole, resurgence, shaft, climate, climacteric forest, limestone, dolomite, Paleozoic, Ordovician, Wufeng, Hubei.


Karstologia Mémoires N° 4 Année 1991 GEBIHE 89 - ISSN : 0751-7628