BEDDING KARST AND MULTILAYERED GROUNDWATER FLOWS IN KARSTIC BLOCK MOUNTAINS IN THE NORTHEAST OF MOUNT XISHAN, TAIYUAN, CHINA

The hydrogeology of the northeastern part of Mt Xishan has historicall y been interpreted in terms of a simple unconfined aquifer model. The groundwater required is characterized by (1) karst terrain, (2) multil ayered unconfined groundwater flow developed in block mountains involv ing rapid hanging discharges and (3) deep confined groundwater with a carbon 14 age of 1000-2800 years and low tritium content. The flows ar e partly towards the southern part of Mt Xishan, partly east towards t he porous aquifers of the Nitun Basin and partly discharging through t he Lancun Spring system. The spatial structure of karst aquifers in bl ock mountains is elucidated by an understanding of stratigraphic, stru ctural, lithological, climatic and karst geomorphological evolution. T he actual complex hydrogeological conditions in the Mt Xishan area con sidered are demonstrated by a comprehensive model proposed by the auth or. Such a model may also be applied in other karstic block mountains.