Gypsum karst geohazards in China
Yaoru, Lu; Cooper, A.H.. 1997 Gypsum karst geohazards in China. In: Beck, Barry F.; Stephenson, J. Brad, (eds.) The engineering geology and hydrogeology of karst terranes, proceedings of the Sixth Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst Springfield/Missouri/6-9 April 1997. A A Balkema, 117-126.Before downloading, please read NORA policies.
China has the worlds largest proven gypsum (CaSO4.2H2O) resources in the world. The gypsum ranges from pre-Cambrian to Quaternary in age and occurs in varied geological environments. The rapid dissolution rate of gypsum means that gypsum karst development can be very fast, resulting in progressively worsening geohazards. This paper reviews the characteristics of the gypsum deposits and their associated geohazards in China.Three kinds of gypsum karst are discussed. These include karst in massive thick beds of gypsum, karst in thin-bedded gypsum and compound karst in gypsum and carbonate rocks. Some site-specific problems are also examined. In the Shanxi coalfield, breccia pipes, or collapse columns, caused by the dissolution of Ordovician gypsum, penetrate the overlying Carboniferous and Permian coal-bearing sequences resulting in difficult coal mining conditions. In Guizhou Province re-activated gypsum karst is associated with leakage of water through the gypsum from a reservoir. Remedial engineering works have been carried out, but leakage still occurs. Groundwater abstraction from gypsiferous sequences is also problematical. It can yield sulphate-polluted water and cause subsidence problems both through gypsum dissolution and groundwater drawdown.
|Item Type:||Book Section|
|Programmes:||BGS Programmes > Physical Hazards|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||09 May 2011 14:10|
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