MODERN PEARL RIVER DELTA AND PERMIAN HUAINAN COALFIELD, CHINA - A COMPARATIVE SEDIMENTARY FACIES STUDY

Sedimentary facies types of the Pleistocene deposits of the Modern Pea rl River Delta in Guangdong Province, China and Permian Member D depos its in Huainan coalfield in Anhui Province are exemplified by depositi onal facies of anastomosing fluvial systems. In both study areas, sand /sandstone and mud/mudstone-dominated facies types formed in diverging and converging, coeval fluvial channels laterally juxtaposed with flo odplains containing ponds, lakes, and topogenous mires. The mires accu mulated thin to thick peat/coal deposits that vary in vertical and lat eral distribution between the two study areas. This difference is prob ably due to attendant sedimentary processes that affected the floodpla in environments. The ancestral floodplains of the Modern Pearl River D elta were reworked by combined fluvial and tidal and estuarine process es. In contrast, the floodplains of the Permian Member D were mainly i nfluenced by freshwater fluvial processes. In addition, the thick, lat erally extensive coal zones of the Permian Member D may have formed in topogenous mires that developed on abandoned courses of anastomosing Fluvial systems. This is typified by Seam 13-1, which is a blanket-lik e body that thickens to as much as 8 m but also splits into thinner be ds. This seam overlies deposits of diverging and converging, coeval fl uvial channels of the Sandstone D-3 and associated overbank-floodplain deposits. The limited areal extent of lenticular Pleistocene peat dep osits of the Modern Pearl River Delta is due to their primary accumula tion in topogenous mires in the central floodplains that were restrict ed by contemporaneous anastomosing channels. Copyright (C) 1996 Elsevi er Science Ltd