EPISODIC TRANSGRESSIONS AND COAL ACCUMULATION: AN EXAMPLE FROM THE LATE CARBONIFEROUS COAL-RICH UNITS IN THE WESTERN SHANDONG COALFIELDS

The extremely gentle slope of the large coal-accumulating basins in the Late Palaeozoic epicontinental seas in North China is believed to be good sites of coal accumulation. The episodic transgressions of sea water,in turn,have provided favourable conditions for the development of peat swamp and the preservation of peat. The results in this study show that many important episodic transgressive horizons may be recognized in the Carboniferous -Permian coal measures. The study of the formation of these transgressive horizons is advantageous to the exploration of the distribution of coal-rich units. In this paper, the authors discuss the genetic relationship between the episodic transgressions of sea water and the formation and distribution of coal-rich units,and the coal accumulation in the western Shandong coalfields with the aid of the theory and method of sequence stratigraphy.