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The water circulation in deep aquifers controls not only chemical composition of the groundwater, but also stable isotope composition. In order to analyze the flow field in the process of the deep groundwater circulation in different aquifers, specimens belonging to the fourth aquifer in the Quaternary (the fourth aquifer for short), the coal and sandstone cranny aquifer in the Permian, and Carboniferous (the coal catena aquifer for short), the Taiyuan group limestone aquifer in the Carboniferous (the Taiyuan limestone aquifer for short), and the limestone aquifer in the Ordovician (the Ordovician limestone aquifer for short) were gained from the top down in Renlou colliery and local Linhuan coalmine district, northern Anhui, China, in the study. δD, δ(18)O, and the content of tall dissolve solids (TDS for short) of these specimens were tested. The experimental results had revealed that the groundwater in the fourth aquifer and the Taiyuan limestone aquifer takes on (18)O excursion and the coal catena aquifer takes on D excursion in Linhuan coalmine district, while excursion characteristic in the Ordovician limestone aquifer is not evident in the coalmine district. By analysis, δ(18)O and the content of TDS are in negative relationship in the groundwater of the fourth aquifer and the Taiyuan limestone aquifer in Linhuan coalmine district, yet δD and the content of TDS are in positive relationship in the coal catena aquifer. Mining greatly influences the fourth aquifer and the coal catena aquifer so the groundwater in the fourth aquifer flows from northwest and southeast to mining areas and the groundwater in the coal catena aquifer flows from around to mining areas. However, mining does not influence the Taiyuan limestone aquifer evidently so the groundwater flows from east to west still.

During the Permian period of the southern China North Plate, a layer of marine mudstone (source rock) with oil and gas potential has been widely deposited, with a thickness of about 10.4 m, but their formation mechanism remains unclear. Here, through the application of various analysis techniques, the mineral composition of the mudstone and a series of related geochemical data are obtained to investigate their sedimentary environment and tectonic setting. Mineral composition analysis describes that marine mudstone is mainly composed of quartz, illite, kaolinite, montmorillonite, and other silicate minerals, while carbonate components such as calcite are rare. Meanwhile, the higher content of clay minerals promoted the organic matter during the deposition period enrichment. Indicators and diagrams (i.e., chemical index of alteration [CIA] [> 80], index of compositional variability [ICV] [~ 0.6], A‐CN‐K, Th/Sr vs. Zr/Sr) reveal that marine mudstone was deposited for the first time under strong weathering. Some trace element ratios and redox elements provide evidence that in warm and arid climates, mudstones are deposited under oxic‐anoxic conditions based on the participation of seawater, which is consistent with the conclusion of palaeomagnetics. The binary discriminant diagrams of Al2O3 versus TiO2, Hf‐La/Th versus Ni‐TiO2 suggest that the marine mudstone parent rock is felsic igneous rock, and the lithology may be granite. Combining the regional structural evolution and the direction of transgression during the sedimentary period, it is speculated that the provenance of marine mudstone is the North Qinling tectonic belt in the southwest of the study area and the Yinshan ancient land in the north.

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