Fracture networks in limestone and dolostone quarries in southern Belgium were analyzed as analogues to fractured subsurface Lower Carboniferous carbonates in the Campine-Brabant Basin (northern Belgium, southern Netherlands and westernmost Germany), which are considered as potential geothermal reservoirs. This study focuses on the difference in fracture density, intensity and connectivity in dolostone and limestone quarry walls, as well as on the relationship between bed thickness and fracture density/intensity. Bedding planes and fractures were interpreted based on orthorectified images of quarry walls. Statistical tests show that fracture density and intensity are significantly larger in the dolostones than in the limestones, which is explained by rock mechanical properties. Fracture connectivity is also highest in the studied dolostones. Interpreted bed thickness is significantly larger in limestones than dolostones, but no correlation is present between bed thickness and fracture density or intensity. This may be explained by the low percentage of bed-bounded fractures in the quarry walls. Fracture density, intensity and connectivity are key parameters influencing permeability, especially in carbonates with low matrix porosity. The results suggest that, in light of fracture properties, Lower Carboniferous dolostones might possess better geothermal reservoir characteristics than limestones.

比利时南部石灰岩和白云岩采石场的裂缝网络被分析为类似于 Campine-Brabant 盆地（比利时北部、荷兰南部和德国最西部）的裂缝性地下下石炭统碳酸盐岩，这些碳酸盐被认为是潜在的地热储层。本研究侧重于白云岩和石灰岩采石场墙的裂缝密度、强度和连通性的差异，以及床层厚度与裂缝密度/强度之间的关系。基于采石场墙壁的正射校正图像解释层理平面和裂缝。统计测试表明，白云岩中的裂缝密度和强度明显大于石灰岩，这可以通过岩石力学性质来解释。在所研究的白云岩中，裂缝连通性也是最高的。石灰岩中解释的床层厚度明显大于白云岩，但床层厚度与裂缝密度或强度之间不存在相关性。这可能是由于采石场壁中床层裂缝的百分比低。裂缝密度、强度和连通性是影响渗透率的关键参数，特别是在基质孔隙度低的碳酸盐岩中。结果表明，从裂缝性质来看，下石炭统白云岩可能比石灰岩具有更好的地热储层特征。强度和连​​通性是影响渗透率的关键参数，特别是在基质孔隙度低的碳酸盐中。结果表明，从裂缝性质来看，下石炭统白云岩可能比石灰岩具有更好的地热储层特征。强度和连​​通性是影响渗透率的关键参数，特别是在基质孔隙度低的碳酸盐中。结果表明，从裂缝性质来看，下石炭统白云岩可能比石灰岩具有更好的地热储层特征。