关键词: 上寒武统　, 测井曲线　, 水文地质试验　, 扫描电镜　, 核磁共振

Abstract: The development of pores,fractures,and other structural features is a key controlling factor for aquifer permea bility and also influences physical and mechanical properties such as rock integrity,density,and strength.Taking the Upper Cambrian aquifer at the Liangbei Mine in western Henan as a case study,this work integrates core logging,borehole logging, hydrogeological tests,scanning electron microscopy (SEM),and nuclear magnetic resonance (NMR) measurements to charac terize the macro-and micro-scale structural attributes of this aquifer.The results are summarised as follows:① In well-logging responses,the formation exhibits low natural gamma-ray values and relatively high lateral resistivity,compensated density,and compensated sonic values;the logging curves are stable,and ultrasonic borehole images indicate sparse macroscopic fractures. ② Hydrogeological parameters show that the permeability coefficient of the aquifer is below n×10-3 m/d,placing it in the slightly permeable category.Tracer tests yield an average groundwater velocity of 0.038 m/d,which is notably lower than that reported for the Taiyuan Formation limestone,Ordovician limestone,and Cambrian limestone aquifers in other areas. ③ Pore-structure analyses reveal porosities ranging from 1.50% to 9.46%,generally low;most samples are dominated by small-to-medium pores (<2 μm),with only a few containing macropores (from 2 μm to 20 μm) and micro-fractures.Collec tively,the macro-and micro-scale test results indicate that the Upper Cambrian strata in the study area are lithologically homo geneous,compact in texture,poorly developed in pores and fractures,low in permeability,and characterised by slow groundwa ter flow.These findings provide a technical basis for evaluating the hydrogeological conditions of the Upper Cambrian aquifer at this mine and also offer a useful reference for studies on aquifer structural characteristics in analogous regions.