Previous studies on the Upper Cambrian of the Jiangnan Slope Belt（Peng，1990）were mostly in the area from eastern Guizhou to western Hunan.Tain（1940）was the first worker to recognize the Cambrian in the district.He divided the Cambrian rocks in the region into 6 Middle to Upper Cambrian lithostratigraphic units（Text-figure 2）.He named the dolomite that cropped out widely in that area as the“Loushankuan Limestone”.Since that early work，northern Guizhou has become a classical area for Cambrian research，and many detailed investigations have been carried out.Liu（1945）placed Tian’s 6 units into 2 units that Lu（1956）assigned to the later Cambrian.During the 1960s and 1970s，considerable regional surveying and mapping was conducted in Guizhou and Hunan.Detailed litho-biostratigraphical studies and trilobite faunas have been recorded previously by Jegorova et al.，（1963），the Regional Survey Team of Hunan（1964），Lin et al.（1966），Yang（1978）and Liu（1982）.Investigations of Cambrian strata and fossils in western Hunan and Guizhou were reviewed by Peng（1984，1987，1990，1992），and Peng and Robison（2000）.Regional Cambrian lithofacies and sedimentary patterns were discussed by Gao and Duan（1985），Ye and Pu（1991）and Pu et al.（1993）.Song（1989）and Dong（1990，1991）documented some Cambrian trilobites and conodonts in the northwestern Hunan.Further investigations of the Middle and Upper trilobite faunas and lithofacies palaeogeography of the Dama-Haichongkou-Shishanguan（Chenxi）areas have been carried out by the present author between 1995 and 2003.Text-figure2 HistoricalreviewoftheCambrianinwesternHunan（platformslopeareas）
