An automatic method for generating curvilinear geological section with stratal pinch-out

Geological Section (GS) map is a kind of fundamental material for studying geological stratum, rock mass and geological structures, which can provide the basic information for geological staff to recognize and analyze geological phenomenon. However, it´s not so easy to automatically generate 3D geological sections for complex geological stratum, especially geological sections with stratal pinch-out. This paper proposed an automatic method for generating 3D curvilinear geological sections with stratal pinch-out based on virtual boreholes. In this method, virtual boreholes are generated by computing the intersection points between interpolated vertical lines and 3D stratum body model, from which boundary contour polygons of stratum can be extracted. In order to maintain geometric integrity and promote level of automation in section generation process, firstly necessary stratum points were added to boreholes which are lack of corresponding stratum, then the boundary contour polygons were tessellated as triangles for 3D visualization of the curvilinear geological section. The method has been implemented and successfully applied in a sample engineering case, which demonstrated that it is able to automatically and efficiently generate 3D curvilinear geological section for pinch-out strata with this method.