Comparison of the Geology Presented in a Cross-Section and That Observed in The Field – A Lesson from the Tomisławice Lignite Opencast Mine, Konin Basin in Central Poland

This article briefly focuses on comparing geological information shown in a cross-section with field data. An example from the Tomisławice opencast mine, where the first Mid-Polish lignite seam (MPLS-1) is currently exploited for electricity production, is used where two sites present large and even surprising differences. In the first case, they are due to technical reasons, i.e., wet drilling. The second case is most likely caused by the compaction of peat during its transformation into lignite. The obtained results clearly indicate that the actual geological structure observed in the field may differ significantly from that which is interpreted on the geological cross-sections based on borehole data.