SEDIMENTARY FACIES AND PALAEOGEOGRAPHY OF SOUTHEASTERN NORTH CHINA PLATFORM DURING THE CARBONIFEROUS

In Shangxi, Hebei, Shangdong, Henan, Jiangsu and Anhui Provinces in southeastern North China Platform, the Carboniferous strata occur on a wide range of scales and abound in mineral resources such as coal and aluminium. The overall palaeotectonic framework typical of epicontinental seas in the Ordovician was inherited during the Carboniferous. During the Benxian, the sea water passed from Qinling-North Huaiyang trough in the south through Feidong strait northwards to Xuzhou and Linyi, and kept on expanding northwards, westwards and southwards, thus resulting in the formation of the epicontinental marine basins surrounded by old land in which the accumulated paraplains were developed and brought the formatian and distribution of the G-layer of bauxite beds under control. Till the Taiyuanian, the sea water from the Qinling-North Huaiyang trough intruded further from western Henan through Funiushan-Huoqiu old land northwards to the Huaihe River basin, resulting in the formation of the vast area of epicontincntal tidal flats in the study area. The pulsating transgression was responsible for the development of the polycyclic, rhythmic coalbearing formations with the intercalations of carbonate rocks and elastic rocks. hifluenced by frequent transgression, the sedimentary coal seams tended to occur as thin coal scams or coal streaks up to ten layers and more in the Huaihe River basin south of 35°N, whereas in the Hebei-Shandong region north of 35°N, weak influence of transgression allowed a great deal of commercial coal beds to be accumulated.
The Carboniferous epicontinental tidal flats in the study area and the eastern part of the adjacent Qinling-North Huaiyang trough were left-rotated and translated by the later-formed Tancheng-Luxian fault and migrated to the Liaodong Peninsula and the northern part of the Shandong Peninsula, being linked up with the Liaoji epicontinental tidal flats and Jiaolai-Linjinjiang trough, respectively. The original North China epicontinental sea during the Carboniferous was an EW-trending, southward-dippin, tidal flat-dominated coal-accumulating sedimentary basin.