兖州煤田北部和西部,第四系下组含水层直覆含煤地层之上,南部和东部仅有红层残存。第四系下组含水层的下段,以稳定的、含水较丰富的细砂及砂砾层为主,与煤系露头风化带和基岩有直接的水力联系,为煤系含水层的主要补给水源。随着矿井开采时间的延长,第四系下组 Yanzhou coalfield north and west, Quaternary aquifer under the coal seam strata above, only the red remaining in the southern and eastern. In the lower part of the Quaternary aquifer, the lower part of the aquifer is mainly composed of stable fine sand and gravel with abundant water and direct hydraulic connection with outcrop weathered belt and bedrock, which is the main supply source of coal-bearing aquifer . With the extension of mining time, the Quaternary group