Abstract:In order to illuminate the mechanism of water-rock interaction in deep aquifers in the concealed coal mining area in North China, taking Suxian-linhuan Mining Area in Huaibei coalfield for example, 166 groundwater samples in 1985 to 2011 were collected or gathered, which belonged to the fourth aquifer of unconsolidated formation, the coal sandstone fissure aquifer, the Carboniferous karst aquifer of Taiyuan formation and the Ordovician karst aquifer. 87Sr/86Sr, 34S and 13C of these groundwater samples were tested, as well as conventional components such as Na++K+, Ca2+, Mg2+, HCO3-, Cl-, SO42-, CO32-. Moreover, tracing and analysis of the water-rock interaction in deep aquifers were carried out based on isotopes and hydrochemistry. The results suggest that, among the main discharge aquifers in the mining area, the coal sandstone fissure aquifer is predominantly characterized by desulfurizing or cation exchange absorption, whereas, the fourth aquifer of unconsolidated formation, the Carboniferous karst aquifer of Taiyuan formation and the Ordovician karst aquifer are predominantly characterized by pyrite oxidation or hardening. The results also suggest that, under mining-induced disturbance, the primary water-rock interaction tends to weaken for the coal sandstone fissure aquifer and the Ordovician karst aquifer, yet, the primary water-rock interaction tends to weaken or strengthen for the fourth aquifer of unconsolidated formation and the Carboniferous karst aquifer of Taiyuan formation, which is controlled by the bedrock level, the fault location and its water-resisting property, the extent of mining-induced disturbance in the mine.