Abstract Armoured mud balls were observed after rainfall and a short flood in the otherwise dry Xiaohe (small river) valley of Guanling County, Guizhou Province, South China, app-
roximately 30 km southwest of Guanling City. Armoured mud balls are most common in semi-arid climates, but rather unusual in a humid climate as in Guizhou. A number of well-rounded mud balls, 2-20 cm in diameter, were found lying on the gravel of the Xiaohe gully floor. The mud balls consist of sticky, light brown and slightly mottled clay without carbonate content. The surfaces of the mud balls were studded with rims of sand- or gravel-size limestone clasts, collected during bedload transport, as is typical for armoured mud balls. The mud balls originated from alluvial mudstone deposits of the valley floor and cliff that are most likely derived from the weathering and karstification of bedrock limestones. Such mudstones seem to be especially well suited for forming armoured mud balls. As flood events are rather common in the area, the formation of armoured mud balls should be very frequent in the Xiaohe valley and similar valleys nearby, giving the possibility for further and more detailed studies. To the best of our knowledge this is the first description of armoured mud balls in China.
Fund:The author is much indebted to Prof. Dr. Xiao-Feng Wang of the former Yichang Institute of Geology and Mineral Resources, China Geological Survey (now Wuhan Institute of Geology and Mineral Resources, CGS), for organizing and generously supporting the Guanling Fauna Project (Wang et al., 2006, 2008), during which the described armoured mud balls were observed. Prof. Dr. H. C. Mult. Gerald M. Friedman, Troy, New York, USA, is thanked for providing additional information on armoured mud balls. Dr. M. Franz, Freiberg/Sachsen is acknowledged for helpful criticism of the manuscript and Prof. Dr. I. Lerche, Halle/Saale for improving the English text. The careful reviews of Profs. Zeng-Zhao Feng and Ming-Xiang Mei, both from Beijing, are gratefully acknowledged.
Corresponding Authors:
*Corresponding author. E?mail: gerhard.bachmann@geo.unihalle.
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Cite this article:
Gerhard H. Bachmann. Armoured mud balls as a result of ephemeral fluvial flood in a humid climate: Modern example from Guizhou Province, South China[J]. , 2014, 3(4): 410-418.
Gerhard H. Bachmann. Armoured mud balls as a result of ephemeral fluvial flood in a humid climate: Modern example from Guizhou Province, South China[J]. Journal of Palaeogeography, 2014, 3(4): 410-418.
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